Watts HF scientific CLX-Ex2 Series User manual

Operations and Maintenance Manual
Chlorine and Total Residual Oxidant Monitor
For Use in Hazardous Environments and Extended Reagent Life
Model CLX-Ex2 28034
IOM-HF-CLX Ex2-28920
WARNING
!
Read this Manual BEFORE using this equipment.
Failure to read and follow all safety and use information can
result in death, serious personal injury, property damage, or
damage to the equipment.
Keep this Manual for future reference.
IOM-HF-CLX Ex2-28920 Rev 4

2
Table of Contents
1.0 Safety .......................................................................................... 3
1.1 Symbols Used in CLX-Ex2 .................................................... 3
1.2 Use in Explosive Environments Safety .................................. .3
2.0 Overview ..................................................................................... 4
2.1 Specifications ......................................................................... 4
2.2 Unpacking and Inspection of the Instrument and Accessories ...... 5
2.3 Instrument Labels .................................................................. 5
2.4 The Display ............................................................................ 5
2.5 The Touch Pad ...................................................................... 5
2.6 Orientation ............................................................................. 5
3.0 Theory of Operation .................................................................... 6
3.1 The Measurement................................................................... 6
3.2 The Air Sentinel Controller ..................................................... 6
3.3 Remote Standby ................................................................... 7
3.4 The Reagents ........................................................................ 7
3.5 The Reagent Cooler .............................................................. 7
4.0 Installation and Commissioning . .................................................. 7
4.1 Mounting and Site Selection ................................................... 7
4.2 Plumbing ............................................................................... 8
4.3 Air Supply .............................................................................. 8
4.4 Electrical Connections ........................................................... 8
4.4.1 RS-485 ......................................................................... 8
4.4.2 Relay ............................................................................ 8
4.4.3 4-20 mA ....................................................................... 8
4.4.4 Remote Standby Connections ...................................... 8
4.4.5 RS-485/4-20 mA cable Ferrite ...................................... 9
4.4.6 Modbus Control ............................................................ 9
4.5 Installing Reagents ................................................................ 9
5.0 Air Sentinel Controller Operation .................................................. 9
5.1 Start Up ................................................................................. 9
5.2 Indicator Lamps ..................................................................... 9
5.3 Maintenance Bypass Operation ........................................... 10
6.0 Operation .................................................................................. 10
6.1 Routine Measurement ......................................................... 10
6.2 Routine Measurement with Remote Standby ....................... 10
6.3 Security Access Feature ...................................................... 11
6.4 The White LED .................................................................... 11
7.0 Instrument Calibration ............................................................... 12
7.1 Slope (gain) Calibration Procedure ....................................... 12
7.2 Zero (offset) Calibration Procedure ....................................... 12
7.3 Restore Factory Settings ..................................................... 12
8.0 Instrument Configuration (CONFIG mode) ................................. 13
8.1 Setting the 4-20 mA ............................................................ 13
8.2 Configuring the Error Level ................................................... 13
8.3 Configuring the RS-485 Port ............................................... 13
8.4 Configuring the Alarm .......................................................... 14
8.4.1 Alarm1 ........................................................................ 14
8.5 Enabling the Security Access................................................ 14
8.6 Extended Settings ................................................................ 14
8.7 Units of Measurement ......................................................... 14
8.8 Averaging and Filtering ........................................................ 14
8.9 LCD Backlight Brightness .................................................... 15
8.10 RS-485 Parameters ........................................................... 15
8.11 Cycle Time ........................................................................ 15
8.12 Water Conservation ........................................................... 15
8.13 4 mA Adjustment ............................................................... 16
8.14 20 mA Adjustment ............................................................. 16
9.0 Additional Features and Options ............................................... 16
9.1 RS-485 Output .................................................................... 16
9.1.1 Simple Communication ............................................... 16
9.1.2 Modbus Communication ............................................. 16
10.0 Troubleshooting ....................................................................... 17
10.1 CLX-Ex2 Fault Detection ................................................... 17
10.2 Setting Flow Rate .............................................................. 17
10.3 Clearing Faults ................................................................... 17
10.4 Reagent Clogs ................................................................... 17
10.5 Diagnostic Chart ................................................................ 18
10.6 Technical and Customer Assistance .................................. 18
11.0 Routine Maintenance ............................................................... 18
11.1 Maintenance Schedule ...................................................... 18
11.2 Replacing or Installing the Reagents .................................. 19
11.3 Indicator Reagent Preparation ........................................... 20
11.4 Check Valve Flushing Kit ................................................... 20
11.5 Instrument Storage ............................................................ 20
11.6 Cleaning the CLX-Ex2 ....................................................... 20
12.0 Accessories and Replacement Parts List ................................ 21
13.0 Ballast Water Market Products Limited Warranty ..................... 24

3
This symbol identifies hazards which, if not avoided,
could result in death or serious injury.
This symbol identifies hazards which, if not avoided,
could result in minor or moderate injury or damage to
the equipment.
This symbol identifies important information,
practices or actions.
This pictorial alert you to the need read the manual,
possibly at a different section.
This pictorial alerts you to electricity, electrocution
and shock hazards.
1.0 Safety
This manual contains basic instructions that must be followed during
the commissioning, operation, care and maintenance of the instrument.
The safety protection provided by this equipment may be impaired if it
is commissioned and/or used in a manner not described in this manual.
Consequently, all responsible personnel must read this manual prior to
working with this instrument.
In certain instances icons or symbols, have been added to give further
clarification to the instructions. Refer to the Table of Contents to easily
find specific topics and to learn about unfamiliar terms.
This manual is intended to be used in conjunction
with No.28749 for more information on the connection
and operation of the Air Sentinel.
1.1 Symbols Used in This Manual
WARNING
!
CAUTION
!
NOTICE
1.2 Use in Explosive Environments Safety
In the interests of safety the operator must ensure the atmosphere
where the instrument is located is safe from gases, vapors, dust or other
flammable conditions whenever the instrument is opened for service or
maintenance. At all other times the door must be kept closed with purge
air connected the purge system operating with the all GREEN lamps lit
indicating safe operation.
WARNING
!
If power is retained to the CLX-Ex2 after opening the enclosure
door while NOT in bypass mode, immediately close the
enclosure door and remove power to the instrument. Contact
HF scientific service department for further instruction.

4
2.0 Overview
The CLX-Ex2 Online Chlorine Monitor allows for the reading of chlorine
levels of process water on-line. The CLX-Ex2 has been designed
to meet the design criteria specified by Standard Methods for the
Examination of Water and Wastewater (21th Edition) Method 4500-Cl
G. DPD Colorimetric Method. The CLX-Ex2 uses a 515nm LED as the
measurement light source.
This instrument has been designed to operate in explosive atmospheres
and meets the IECEx rating as stated in the specifications. The instrument
does this with the use of an approved purge/pressurization controller
called the Air Sentinel. Please refer to the companion manual Cat. No.
28749 for all information on:
• Operation of the Air Sentinel.
• Electrical power connections.
• Purge Air Connection.
*Viton®is a trademark of The Chemours Company FC, LLC
Noryl®is a registered trademark of SABIC Global Technologies B.V.
2.1 Specifications
Measurement Range 0.00 – 10.00 mg/L (PPM) or 0.00 – 15.00 mg/L (PPM)
Accuracy For 0.00 – 10.00 mg/L Range: ±5% of reading or ±0.03 mg/L (PPM) whichever is greater for range of 0-6.0 mg/L(PPM)±10% of reading
from 6.01-10.00 mg/L (PPM)
For 0.00 – 15.00 mg/L Range: ±10% of reading or ±0.03 mg/L (PPM) whichever is greater
Resolution 0.01 mg/L (PPM)
Cycle Time Adjustable; 60 seconds to 10 minutes (600 seconds)
Display Multi-Line Liquid Crystal Backlit Display
Alarms One NO relay contact 120-240VAC 2A
Analog Output Powered 4-20 mA, 600 Ω drive, isolated
Communications Port Bi-directional RS-485 with Modbus
Water Pressure Integral pressure regulator 0.34 bar (5.0 PSI) to 10.3 bar (150 PSI.)
Flow Rate to Waste 200 – 400 ml/min.
Operating Temperature 0°C – 55°C (32°F – 131°F)
Wetted Materials PVC, Borosilicate Glass, Reslyn (FFKM), Viton®(FKM), Polypropylene, 316 Stainless Steel, Acetal, Noryl®, Silicone
Sample Temperature Range 0°C – 55°C (32°F – 131°F)
Power Supply 100 to 240VAC, 47-63 Hz, 250VA
Insulation Rating Double Insulated, Pollution Degree 2, Overvoltage Category II
Environmental Conditions Altitude up to 2000 meters
Up to 95% RH (non-condensing)
IECEx Hazloc Rating Ex pxb IIC T4 Gb 0°C ≤ Ta ≤ 55°C
Compressed Air Water and oil free, -40°F (-40°C) Dew Point, Particles <5u, ISA Grade Hydrocarbon Free. Full time clean dry air at 5.5 - 7 bar
(80-101.5 PSI) @35 SLPM (1.2 SCFM) @ 20°C (68°F) Max
Regulatory Compliance and Certifications CE Approved, ETL listed to UL 61010-1 Issued May 11 2012 3rd Ed and ETL certified to CSA 22.2 No. 61010.1 issued May 11 2012
EN61326:2006
Shipping Weight 27.2kg (60lbs.) Reagents are Shipped Separately
Shipping Dimensions 93 cm X 62 cm X 32 cm (36½" X 24½" X 12½")
In addition this instrument has vortex cooling. This instrument will
automatically control a connected compressed air line to lower the
temperature of one of the reagents, allowing the reagent an operating
life of up to 3 months.
Every effort has been made to ensure the accuracy of this manual. Due to
the continuous development and improvement of all instrumentation, there
may be slight differences between this manual and the instrument received.
Therefore, no legal claims can be made against any discrepancies herein.

5
Purpose Location Label
Serial number,
manufacturer, part
number, power
rating, CE and UL
marking
Front of
Enclosure
Warning and
informational
Front of
Enclosure
Informational Front of
Enclosure
2.3 Instrument Labels
The following labels should be applied to the outside of the enclosure.
2.4 The Display
Figure 1 illustrates all the items that can appear on the display. The
upper row of the display (1) is used for reporting the chlorine levels and
to provide user guidance in the customer setting routine. The lower row
of the display (2) is used to communicate error messages (message
queue) and provide user guidance. The display has two icons (3)
that are used to indicate the use of access code and offset mode. In
addition, mode arrows (4) are used to indicate the current instrument
operating mode; AUTO (normal operation), CAL (calibration) and
CONFIG (configuration).
Figure 1: Display used in the instrument
2.5 The Touch Pad
Figure 2 illustrates the touch pad. The touch pad has six buttons:
PRIME, SERVICE, MODE/EXIT, , and 
The MODE/EXIT button is used to cycle between the three operational
modes of the instrument: CAL, CONFIG, and AUTO (Measurement)
mode. The button enters the option or mode that is highlighted or
chosen. The and buttons are used to change settings.
The PRIME and SERVICE buttons are dedicated controls. The PRIME
will start 75 reagent pump pulses to prime the tubing after a change
or addition of reagent bottles. The SERVICE button will drain the
instrument and hold all operations until either the SERVICE button is
pushed again or the power is reset. This button should be used while
changing the tubing, the measurement cuvette or reagent bottles.
Figure 2: The CLX-Ex2 touch pad
2.6 Orientation
From the diagram below the major components can be located.
Note that two reagents are required the buffer and the indicator. The
reagents are discussed in the Routine Maintenance section 11.0.
Figure 3: The CLX-Ex2 with Cover Open
2.2 Unpacking and Inspection of the
Instrument and Accessories
The table below indicates the items included in the shipment.
Item Quantity
CLX–Ex2 Monitor 1
Instruction Manual 1
Tubing/Cuvette Kit: 8 black pump tubes, 2 different Cap Assemblies,
1 replacement cuvette
1
Check Valve Flushing Kit 1
Remove the instrument from the shipping crate. Carefully inspect all
items to ensure that no visible damage has occurred during shipment. If
the items received do not match the order, please immediately contact
the local distributor or the HF scientific Customer Service Department.

6
3.0 Theory of Operation
3.1 The Measurement
The CLX-Ex2 has two solenoid valves, one for sample water (FLOW)
and one for draining of the cuvette (PURGE). A third solenoid, along
with four check valves forms a reagent pump. Sample water flow is
controlled by the FLOW solenoid valve. The PURGE solenoid valve is
used to empty the cuvette in the measurement chamber.
The measurement chamber consists of a sample inlet, a purge drain,
and an overflow. The reagent is added from the check valves integrated
into the lower portion. A green LED provides the 515 nm source
lamp, a red LED is used for sample level and flow measurement. A
single detector is located 180º from the green LED. A replaceable
glass cuvette separates the LEDs from the detector and maintains
the measurement path length. Sample water flows in the inlet at the
bottom, through the measurement cuvette and out through an overflow
drain. This flow is used to both fill the cuvette and flush the system.
The reagents are dispensed from two replaceable bottles. One bottle
has a buffer to control the pH; the second has an indicator that contains
the DPD, which produces color when chlorine is present in the sample.
The degree of color is dependent on the amount of chlorine in the
sample water.
The measurement chamber is open to view operations. A white LED
backlights the chamber for a clearer view. The white LED will flash to
attract attention in the case of a warning or failure. Most warnings and
failures are also displayed on the screen. To prevent interference, the
white LED is turned off during measurements.
During normal operation the CLX-Ex2 will run through a timed cycle.
A simplified cycle will consist of the following sequences:
• Flushing – continuous sample flow
• Purging – PURGE valve opens
• Zeroing – no flow with cuvette full
• Adding Reagents – one pulse of the reagent pump
• Mixing with sample – sample flow pulses in
• Reading resulting sample – no flow with cuvette full
• Purging – PURGE valve opens to remove reacted sample
The cycle above is simplified and does not describe all the actions
and testing that occurs. The CPU continuously diagnoses the entire
system for correct operation and sample water flow. If an error occurs,
a message is posted to the message queue on the LCD screen.
The reagent is added by a single pulse of the reagent solenoid. When
the reagents require replacement, the PRIME button is pushed to bring
new reagents into the system. During PRIME the reagent solenoid is
pulsed several times to draw fluid from the two reagent bottles and
fill the tubes with new reagent. A complete PRIME takes less than
a minute.
The SERVICE button empties the cuvette, stops the flow of sample
water, and clears any errors. This provides a convenient way to replace
reagents and the measurement cuvette. If more extensive servicing
is performed, all power to the CLX-Ex2 should be removed. If the
CLX-Ex2 is to be turned off, it is recommended that the instrument be
placed in SERVICE mode before removing power. This ensures that
the cuvette is emptied and the flow is off.
3.2 The Air Sentinel Controller
The Air Sentinel controller governs the power to the instrument. For
normal instrument operation air needs to passes through fitting on
the base of the main enclosure and constantly purge any vapors that
could build-up. All GREEN lamps indicate a safe operating condition.
Only when this condition is reached will power be applied to the
measurement portion of the instrument.
Start-up
At start-up with the enclosure door open the Air Sentinel will display a
RED PRESSURE lamp on the visual indicator indicates that the system
is not pressurized and no power is sent to the instrument.
Closing the door with the air pressure applied, will cause the Air
Sentinel to display a GREEN PRESSURE lamp and a RED TIMER
lamp. During this time the enclosure will undergo an automatic dilution
purge period of 5 minutes where at least 5 volumes of free space inside
the enclosure will be exchanged with clean purge air. No power is
applied to the rest of the instrument during this time.
After the enclosure air has gone through this purge period the Air
Sentinel will display all GREEN lamps. At this time the instrument is
deemed safe and power is applied to rest of the instrument.
Do not apply power to the Air Sentinel controller unless the area
has been properly tested and is known not to contain explosive
materials.
Bypass Key
Use of the bypass key disables the safety features and safe
operation of this instrument. It is imperative that this operation
be performed only after the area has been tested and known to
be safe.
If power is retained to the CLX-Ex2 after opening the enclosure
door while NOT in bypass mode, immediately close the
enclosure door and remove power to the instrument. Contact
HF scientific service department for further instruction.
Assuming the area has been tested and is known not to contain
explosive materials; a bypass service key is provided and can be
used. In this operating mode power will be retained to the rest of the
instrument even though the door is open. It is imperative that this mode
is only used after area is known to be safe. This operation disables the
safe operation of this instrument.
Upon turning the key, the indicator will display the RED BYPASS &
TIMER lamps. This is an indication of the maintenance mode. Power
is retained to the instrument. The key cannot be removed in this mode
of operation.
After maintenance has been performed the door should be closed
and latched. Air pressure will once again pressurize the enclosure. The
maintenance key can now be turned and removed and the key cover
replaced. The purge controller will display GREEN PRESSURE &
BYPASS lamps indicating a safe operation and power is kept applied
to the instrument. The TIMER lamp will remain RED for 5 minutes to
indicate a bypass operation had taken place.
WARNING
!

7
3.4 The Reagents
The indicator reagent reacts with any oxidant, generally chlorine, to
create a pink color which the instrument measures and compares with
a sample of water without reagents.
The buffer reagent is required to control the sample pH to bring the
sample to neutral. The reagents are provided already hydrated and
require little operator preparation.
Each 125 mL indicator will require the addition and mixing of the DPD
powder contained in the small brown bottle. This activates the indicator
reagent. The indicator reagents should be changed out on a 90 day
basis even if they are not fully used.
The 500 ml buffer does not require any preparation and is good for
one year.
After one year all the reagents will have been consumed and replacement
reagent set will be required. This can be ordered through agent Catalog
No.09991. This set will include four sets of Indicator reagents plus one
500 mL bottle of Buffer.
3.3 Remote Standby
This feature will allow for remotely placing the instrument into a standby
mode. This can be done to lower reagent usage while not performing
ballasting or de-ballasting operations. The last operation of each
cycle is a flush and hold. Whenever the instrument is not being used
(standby), it is stored such that the optics is clean and dry.
Dry contacts are provided as feedback as to the operation
of the instrument (operating or standby). For more
information on this feature refer to sections 4.4.4 Remote
Standby Connections and 6.2 Routine Measurement with
Remote Standby.
3.5 The Reagent Cooler
A reagent cooler is provided for the 125 ml indicator reagent.
For proper operation power must be applied by the Air Sentinel controller
to the cooling chamber temperature controller. Clean dry compressed
air must also be provided at pressures between 5.5 and 7 bar (80 to
101.5 PSI).
The cooling chamber temperature controller governs the solenoid
which controls air flow to the vortex cooling unit. The air flow is turned
on or off as required to maintain the indicating reagent temperature at
20-25˚C. This extends the life of the reagent up to 90 days.
To provide this extended reagent life, power to the cooling power supply
and air pressure must be supplied full time.
4.0 Installation and Commissioning
Prior to use for the first time, one of the reagents
(the indicator) will have to be mixed. Refer to section
11.2 Replacing or Installing the Reagents.
4.1 Mounting and Site Selection
The instrument is designed for wall mounting. Choose a location that is
easily accessible for operation and service and ensure that the Purge
Control lamp is about eye level. Consideration must be made for the
plumbing and electrical conduit connections. The overall mounting
dimensions of the instrument are shown in Figure 4.
Figure 4: Overall Mounting Dimensions of the Instrument
Be sure that the instrument be mounted as close as possible to the
sampling point to ensure a quick response time (within 2-3 meters
(6-10 ft) of the sampling point).

8
4.2 Plumbing
The instrument is designed to require very little head pressure to operate,
but will need around 0.34 bar (5 PSI). The maximum pressure for proper
operation should not exceed 10.3 bar (150 PSI). The maximum
allowable fluid temperature is 55°C (131°F).
NOTICE
The fluid waste from drain connection of this instrument contains
reagents diluted with large quantities of sample water. HF scientific
recommends that in the case of ballast installations, the waste
stream is reintroduced to the bilge tanks. This waste fluid must
NEVER be reintroduced into the incoming water stream.
All plumbing connections are intended to be made through stainless
steel connections.
The water sample inlet requires 6 mm OD stainless steel tubing. The
fitting is a compression fitting so the installer need only place the
supplied the nut and feral over tubing and tighten.
The water drain requires 12 mm OD stainless steel tubing. This fitting is
also a compression fitting so the installer need only place the supplied
the nut and feral over tubing and tighten.
Properly installed and sealed connections are required to ensure the
water tightness and ratings of the instrument.
NOTICE
The drain must be open to the Atmosphere for proper operation.
4.3 Air Supply
This instrument requires water and oil free air, (-40°C [-40°F ] Dew
Point, Particles <5u, ISA Grade Hydrocarbon free). The air needs to be
provided at between 5.5 and 7 bar (80-101.5 PSI) with a volume of 4
cubic foot/min as measured at 5.5 bar (80 PSI). This air supply must be
provided continuously from a known safe area. Min flow is 35 SLPM
The air connection requires 6 mm stainless steel tubing. A compression
type fitting is supplied on the base of the main enclosure that simply
requires the installer to slip the supplied nut and feral over the tubing
and then tighten the nut.
4.4 Electrical Connections
All electrical connections must pass through the three compression
grommets on the left side of the instrument. Cabling must be selected
to ensure that these connections are tight. The grommets can accept
cabling from 11 to 21 mm diameter. One grommet is supplied for
system power and two are supplied for low voltage I/O connections.
These grommets must be tightened to maintain cabinet air pressure.
Most of the low voltage electrical communication connections to the
instrument are made at the termination area which is located on the
left side of the instrument. Remove the access cover by loosening the
captive screw. The connections are labeled and are self-descriptive.
Please follow all government recommendations for installation of
electrical connections to and between the instrument and other
peripheral devices.
All terminals are designed to accept wires in the range of 14-28 AWG.
All wires should be stripped to a length of 6 mm (¼").
For line power connections refer to the companion
manual Catalog No. 28749.
4.4.1 RS-485
The RS-485 half-duplex (2-wire) digital interface operates with differential
levels that are not susceptible to electrical interferences. This is why
cable lengths up to 3000 ft can be implemented. The last device on
each bus may require terminating with a 120 ohm resistor
to eliminate signal reflection on the line. Do not run RS-485
cables in the same conduit as power. Set-up of the RS-485
is covered in 8.3 Configuring the RS– 485 Port.
To prevent damage to the instrument,
ensure that power is disconnected
prior to making connections. For ease
of connecting, remove the plug-in
terminal block. Connections are
labeled beside this termination on the
PC board. The recommended cable
is 22 AWG shielded twisted pair. The
grey terminal block is removable to
assist in making connections.
4.4.2 Relay
One relay alarm connections labeled
ALM COM & ALM NO is provided.
Please note that this is a fail- safe so
the “normal” condition is power to the
CLX-Ex2 on and no alarm condition.
The relay is rated 240VAC
2A. Operation of this alarm
is covered in section 8.4
Configuring the Alarm.
4.4.3 4-20 mA
The 4-20 mA output is driven by a 15 VDC power source and can drive
recorder loads up to 600 ohms. Transformer isolation is provided on
the CLX-Ex2.
Do not run 4-20 mA cables in the same conduit as power.
Operation of this output is covered in section 8.1 Setting
the 4-20 mA.
To prevent damage to the instrument, and for general safety
ensure that power is disconnected to the CLX-Ex2 prior to making
any connections. Polarities of the connections are labeled beside this
termination on the PC board.
The recommended cable is 22 AWG shielded twisted pair. To prevent
ground loops, connect the shield at either the CLX-Ex2 or at its
destination, but not both. The grey terminal block is removable to assist
in making connections.
The 4-20mA is factory calibrated. An adjustment is available
on the 4-20mA in sections 8.12 and 8.13. In addition to
making adjustments, these menus output continuous 4 mA
or 20 mA and can be used as a signal test. Remember that
the configuration mode will timeout after 15 minutes.
4.4.4 Remote Standby Connections
The instrument operates on user control software, where an external
control initiates each cycle. This control line is called the RSI short for
Remote Standby Input.
The CLX-Ex2 will indicate the current status on another line called RSO
or Remote Standby Output. These connections are a relay contact that
is closed when busy and open during when in standby mode.
The connections are labeled RSI and RSO. The RSI has + and – polarity
connection associate with it and expects a 24VDC control signal.
The RSO is simply a relay contact and is not polarized.

9
4.4.5 RS-485/4-20 mA cable Ferrite
To meet IEC requirements for RF radiated immunity a clamp-on type
ferrite is supplied in the accessory kit. It should be placed on the RS-
485 or 4-20 mA cable outside, as close as possible to the CLX-Ex2. If
both outputs will be used, an additional ferrite will be needed and can
be ordered from HF scientific Catalog number 24560T.
4.4.6 Modbus Control
In addition to the above mentioned Remote Standby Connections,
the same control can be achieved using Modbus control. Two special
Modbus addresses are provided.
The reading cycle is initiated using the coil 00005 with default at False
(0). Setting this address to True (1) initiates the reading cycle.
At any time the standby status can be check at Modbus Coil Address
00005 or Modbus Input Address 10005. False (0) indicates standby
and True (1) indicates the measurement cycle is taking place. Control is
only available from the Coil Address 00005.
4.5 Installing Reagents
The CLX-Ex2 will require that two reagents be installed
prior to operation. These are a buffer and an indicator. For
reagent preparation refer to section 11.2 Replacing and
Installing the Reagents.
5.0 Air Sentinel Controller Operation
The Air Sentinel controller is mounted on the side of the main enclosure.
This controller will ensure proper safe operation of the CLX-Ex2. If of all the
required conditions are met, the controller will act as a power governor. It
does this by monitoring the pressurization of the main enclosure with clean
dry air. Should this air supply pressure fail the PRESSURE lamp on the
Air Sentinel unit will turn RED and power to the rest of the instrument
is disconnected.
5.1 Start Up
When power is applied to the CLX-Ex2 for the first time,
ensure that the air supply is connected as stated in section
4.3 and the cabinet is closed and locked. Once power is
applied, the Air Sentinel will go through a purge period of
5 minutes where at least five volumes of the enclosure are
pushed through the CLX-Ex2 and out the Air Sentinel vent. During the
purge period the TIMER lamp Air Sentinel will be RED indicating the
purge is in process and no power is applied to the rest of the CLX-Ex2.
At the complete of the purge, the TIMER lamp will go GREEN and
power will be applied to the rest of the system. As long as the proper
air supply conditions are met the CLX-Ex2 will continue to operate.
Do not apply power to the Air Sentinel controller unless the area
has been properly tested and is known not to contain explosive
materials.
5.2 Indicator Lamps
The indicator lamps are a very quick way to determine to operation of
the controller and thus the safety condition of the CLX-Ex2.
Lamp Color Matrix Function Default
All lamps GREEN Safe Operation Power ON
TIMER lamp RED Instrument purging or Bypass
operation Power OFF
PRESSURE lamp RED Unsafe Operation Power OFF
BYPASS lamp RED Bypass Key Operating Power ON
No Lamps on No power applied to CLX-Ex2 No power applied
everything off
Using the table above, you can quickly determine the operating
condition of the instrument. Under normal operation all GREEN lamps
should appear.
WARNING
!

10
5.3 Maintenance Bypass Operation
Use of the bypass key disables the safety features and safe
operation of this instrument. It is imperative that this operation
be performed only after the area has been tested and known to
be safe.
NOTICE
When shipped from the factory the bypass key is shipped on
the strap securing the key cap. Once the commissioning of the
system has been done these should be moved to a known secure
location. It is not advised that they be left on the strap.
To perform some maintenance operations on the CLX-Ex2 it is necessary
to have the entire instrument powered up while the enclosure door is
open. Under these conditions normally the Air Sentinel controller would
determine that the enclosure is not pressurized and power will be removed
to the measurement section of the CLX-Ex2. To allow for this situation, a
special maintenance bypass key is supplied.
Located on the right side of the Air Sentinel controller is a knurled cap.
Removing this cap reveals the key slot. Insert the key, push in slightly
and turn it clockwise to engage the bypass operation. The TIMER &
BYPASS lamps will turn RED to indicate the bypass mode. Assuming
the area around the CLX-Ex2 has been tested and known to be safe,
the enclosure door can now be safely opened and power will remain on
to the entire system. The key cannot be removed while operating in the
maintenance bypass mode.
Do not operate the CLX-Ex2 for long periods of time in the bypass
mode. This is intended only for maintenance operations.
Do not operate the CLX-Ex2 in the bypass mode unattended.
To return the instrument to normal, safe operation, close the enclosure
door. Ensure that the air supply is connected turn the key counter-
clockwise and remove. Replace the key cover. If the pressure in the
cabinet has built up to a normal acceptable level, the Air Sentinel will
show all GREEN lamps and the instrument will continue to run.
6.0 Operation
Under normal operation the Air Sentinel controller lamps will all be
GREEN indicating safe operation. If the lamps are not GREEN, correct
this condition first. Please refer to section 5.0 Air Sentinel Controller
Operation.
The CLX-Ex2 Online Chlorine Monitor allows for the measurement of
the chlorine of process water on-line. The chlorine value of the process
water is usually reported in milligrams per Liter (mg/L), these units are
equivalent to Parts Per Million (PPM).
The CLX-Ex2 has two available measurement ranges, 0.00 – 10.00
or 0.00 – 15.00 mg/L (PPM). Although the unit will display above the
range, these readings will not be within the stated accuracy. As the
reagents degrade due to aging, readings above the set range may
decrease in value.
6.1 Routine Measurement
First, ensure that all plumbing and electrical connections are complete
before continuing.
The following steps describe how to measure the value of chlorine of a
sample using this instrument:
1. Apply power to the instrument and allow the unit to warm up. The
instrument may have to re-calibrate the water level sense detector.
This WCAL or water calibration will take few minutes to perform.
2. When a continuous process stream is flowing through the
instrument, the instrument will display the measured chlorine level
of the sample by displaying it on the LCD screen. In addition, the
equivalent signal is provided on the analog (4-20 mA) output, or the
digital (RS-485) output, depending on the options selected.
6.2 Routine Measurement with
Remote Standby
First, ensure that all plumbing and electrical connections are complete
before continuing.
The following steps describe how to measure the value of chlorine of a
sample using this instrument:
1. Apply power to the instrument. The instrument will perform a water
calibration (WCAL). During this time the RSO contact will be closed,
indication the system is busy. This automatic calibration is necessary
and will only be performed once on power up.
2. When the system has completed the WCAL, the RSO contacts will
open indicating that it is in standby mode and is ready to take a
measurement.
3. Application of 24VDC to the RSI+ will initiate a read cycle. The RSO
contacts will close to indicate the system is busy.
4. At the completion of the cycle, the RSO contacts will open and the
measured chlorine level of the sample will be displayed on the LCD
screen. In addition, the equivalent signal is provided on the analog
(4-20 mA) output, or the digital (RS-485) output, depending on the
options selected.
The system is ready to take another measurement.
As mentioned previously the same control can be
performed via Modbus. Setting Coil 00005 to a 1 will start a
cycle. See 4.4.6 Modbus Control.
WARNING
!
WARNING
!

11
These screens can be seen through the window of the CLX-Ex2
with the door closed, however to access the anything other than
measurement screens requires that the instrument be placed in bypass
and the enclosure door be opened.
During normal operation, the instrument will have the arrow beside
AUTO highlighted with the current scale displayed on the lower row of
the display and the measured reading on the upper row of the display
(see screen shown).
The screen depicted indicates that the system has just been started
or just entered AUTO mode from Service mode and no readings have
been taken yet.
NOTICE
Please note that calibrations will not be allowed until a reading
is posted.
6.3 Security Access Feature
The instrument is equipped with a security access code feature that
can be activated in the configuration mode. If the security feature is
enabled, the screen shown in the illustration below will appear when
the MODE/EXIT button is pressed.
The security code (333) must be entered to gain access to CAL or
CONFIG menus. Notice that the first number in the code is flashing.
The flashing indicates that this is the number to be changed. Use the
or arrows to select the first of the three numbers in the code and
then press the button to accept the first number of the code. Now
enter the second number in the code. Proceed as with the first number
followed by . Then repeat the process for the third number in the
access code, and finish with the button.
If the valid access code has been selected, the instrument
will be directed to the calibration mode. If the wrong access
code is selected, the instrument will return to the AUTO
mode. Refer to section 8.4 Enabling the Security Access
for more information.
6.4 The White LED
A white LED is used to illuminate the measurement cuvette for easy
viewing of the instrument operations. During the Zeroing portion of
the cycle and the Measurement portion of the cycle, when the green
LED is active, the white LED is turned off to lower interference. This is
normal operation for the instrument and does not represent an error
or problem.
The white LED is also used to draw attention to a problem
as described in section 10.1 CLX-Ex2 Fault Detection. In
these instances the white LED blinks at a constant rate
dependent on the severity of the problem, but is still turned
off as described above. Please note that any fault is always posted to
message queue on the lower portion of the LCD.

12
7.0 Instrument Calibration
The instrument was tested prior to leaving the factory. The instrument
operates from a pre-determined calibration curve for high accuracy
of residual oxidant concentration. It is not necessary to recalibrate to
maintain accuracy specifications.
If re-calibration is required by a regulatory authority, this can easily be
performed if required. The method is by comparison against another
instrument, such as a laboratory or hand held photometer (such as HF
scientific’s Chlorine Pocket Photometer).
There are two points of calibration. The slope or gain and the zero (offset).
To perform the zero calibration, the instrument must be plumbed to a
sample of known chlorine free water, such as de-ionized water for a
zero adjustment.
7.1 Slope (gain) Calibration Procedure
It is important that the chlorine level be quite stable to use this method.
The comparison will be made against a trusted measurement such as a
chlorine photometer, spectrophotometer, or an amperometric titration.
1. Obtain a grab sample of the flow prior entering the instrument.
2. Measure the value of the sample with one of the methods shown above.
3. On the CLX-Ex2, press the MODE/EXIT button once. The screen is
shown below.
4. Press to enter the calibration adjustment.
5. The screen will show the current reading on the CLX-Ex2. Using the
and buttons adjust the reading to agree with the laboratory
method or portable photometer.
6. Press to accept the calibration adjustment and return to AUTO
measurement mode.
NOTICE
There is a limit to the size of the change that can be made to a
current reading. The upper limit is the current reading times 1.5.
The lower limit is the current reading divided by 1.5.
Ensure a reading is posted to the display before calibrating to
avoid a nOnE error.
7.2 Zero (offset) Calibration Procedure
Generally this calibration is only required if readings are expected to be
below 1 mg/L or if it is required by a regulatory authority. To perform
this calibration, the water supply to the CLX-Ex2 must be changed to
chlorine free water such as de-ionized water. This chlorine free water
must be run through the instrument for at least 5 minutes prior to using
the following procedure.
1. On the CLX-Ex2, press the MODE/EXIT button once. The screen is
shown below.
2. Press either the or buttons to get the following screen.
3. Press to enter the zero calibration screen.
4. The screen will show the current reading on the CLX-Ex2. Since
there is no chlorine, the only reading may be a slight offset due to
the absorbance of the reagents. There should be no pink color
developed.
5. Press to perform a Zero calibration. When the calibration has
completed the instrument will return to AUTO measurement
mode automatically.
NOTICE
There is a limit of ±0.20 mg/L total adjustment available. A ZERO
Cal. greater than this will cause a CAL warning and no calibration
will have occurred. Enter SERVICE mode to clear this error.
7.3 Restore Factory Settings
If the CLX-Ex2 displays a CAL error or the calibration was incorrectly
performed, it may be preferred to restore the factory calibration. All
factory defaults settings including the factory calibration can be reset
by holding down the button and then pressing and releasing the 
button then releasing the button.

13
Please note that these operating screens cannot be seen
except through the door window with the cabinet door
closed or in maintenance bypass mode. See section 5.3
for more information on this.
If changes to the configuration have to be performed, you will need to
enter the maintenance bypass mode see section 5.3 for more information.
The instrument has been designed to provide the ability to customize the
instrument according to needs at any time during normal operation. This
mode has been split into sub-menus to facilitate instrument configuration.
This section describes how to use each of the sub-menus to configure the
instrument. While in the configuration mode, the instrument has a time-out
feature that automatically returns the system operation to the AUTO mode
after a fifteen (15) minute period of no button pushes.
Enter the CONFIG mode of the instrument by pressing the MODE/EXIT
button until the arrow beside CONFIG is illuminated, then press the 
button to scroll through the sub- menus.
8.1 Setting the 4-20 mA Output
The first configuration selection is 4-20 for the 4-20 mA
output. Select the either On or OFF using the and 
buttons. Once the desired output has been set, press the
button to accept it. The next prompts will depend on the
output selected. Also see sections 8.12 and 8.13.
If the 4-20 mA output was turned On, prompts to set the 4mA (4MA) and
20mA (20MA) chlorine limits will be displayed. There will also be a menu
to adjust the error level (ERLV). The first prompt will be the chlorine limit
assigned to the 4 mA output level:
Select the chlorine level to assign to the 4MA using the and buttons.
Once the desired level has been set, press the button to accept it.
NOTICE
To exit the CONFIG mode, press the MODE/EXIT button any
changes that were made will be saved.
NOTICE
The 4MA can be set higher than 20MA level to invert the output
current if required. This may be required to control a dosing pump.
The next prompt will be the chlorine level assigned to the 20MA. Select
the chlorine level using the and buttons. Once the desired level
has been set, press the button to accept it.
8.2 Configuring the Error Level
In case of an error in the CLX-Ex2, the 4-20 mA reading can be used to
indicate a problem by sending the current to either 4.00 mA, 2.00 mA or 0
mA. The factory default setting is OFF. Select the desired ERLV by using the 
and buttons then press the button to accept the desired error response.
8.3 Configuring the RS–485 Port
The instrument is equipped with an RS 485 port which operates in
Simple bus or Modbus. Prompts will appear for setting the baud rate,
the address and the Modbus transmission mode (RTU or ASCII).
Select the correct baud rate (1200, 2400, 4800, 9600, or 19200) for
operation of the I/O port by pressing the or buttons to change the
displayed baud rate.
Press the button to continue on and select the desired instrument
address using the or buttons. Once the selection is satisfactory,
press the button.
To use the Modbus mode, select ASCII or RTU. See
section 9.1.2.
Only access when the atmosphere has been tested and known to
be safe.
WARNING
!
8.0 Instrument Configuration
(CONFIG mode)

14
8.4.1 Alarm 1
Alarm 1 Function: The ALM1 is displayed and the display indicates
the current function of alarm 1 (HI, LO, OFF, or Error). Use the or
buttons to cycle through and select the desired function. Press the 
button to accept the selection.
Alarm 1 Set Point: This prompt is used to select the set point for this
alarm; this is indicated by “S/P” shown on the lower row of the display.
Select the desired alarm level by using the and buttons. Once the
desired set point has been set, press the button to accept it.
The Remote Standby limits the relays to a single
normally open connection.
NOTICE
Due to the cyclic nature of the CLX-Ex2, relay chatter is not an
issue. There is no need for alarm delays or hysteresis.
8.5 Enabling the Security Access
The instrument is equipped with a security access. If
this option is turned on, the user is required to input the
access code into the instrument to get to any mode other
than AUTO. The only code is 333. This code may not be
changed. See section 6.3 for more information on this
security feature. The security key icon will be visible and flashing on
the display whenever the access option is selected using the or 
buttons. (On or OFF).
8.6 Extended Settings
The last settings are grouped together to prevent them from being
adjusted by accident. To gain access to the extended settings, select
On using the or buttons and press the button.
If extended settings are set to OFF, pressing the button will save all
settings and the CLX-Ex2 will automatically return to the normal AUTO
mode of the instrument.
8.7 Units of Measurement
The unit of measure can be set to either mg/L (milligrams per liter) or
PPM (parts per million). The factory setting is mg/L. Select the desired
UNIT using the and buttons and press the button to accept it.
8.8 Averaging and Filtering
The CLX-Ex2 can display and output averaged readings to help
smooth out the response and eliminate large reading variation in rapidly
changing processes. There are 5 settings for the averaging feature:
1 = No averaging, each reading is in “real time”.
2 = The current reading and previous reading are averaged.
3 = The current reading and previous 2 readings are averaged.
4 = The current reading and previous 3 readings are averaged.
5 = The current reading and previous 4 readings are averaged.
The factory setting is averaging of 2. Select the desired AVG using the
and buttons and press the button to accept it.
mg/L screen
PPM screen
8.4 Configuring the Alarm
One relay is provided that are designed to operate as an independent
programmable alarm or as a system problem alarm. Please note that
changes to the alarm will not be recognized until the start of the next
cycle. Two settings must be selected to fully program the alarm:
1. The alarm function (HI, LO, OFF or Error)
2. The alarm set point (level at which the alarm activates)
These items are described below:
Alarm Function: The alarm can either be turned OFF or selected to
operate in one of three different manners:
1. HI alarm: the relay changes state when the measured chlorine level
is higher than the programmed alarm level (set point).
2. LO alarm: the relay changes state when the measured chlorine level
is lower than the programmed alarm level (set point).
3. Error alarm: If there is a system fault or problem the alarm will
change states.
Alarm Set Point: The level at which the alarm activates is called the
alarm set point. On the instrument, the alarm set point is designated
as “S/P”. The set point is adjustable to any valid chlorine level over
the range of the instrument in steps of 0.01 mg/L. This setting is not
available if the Error function is chosen.

15
8.9 LCD Backlight Brightness
The LCD backlight brightness may need to be adjusted. This is of
particular interest if multiple instruments are located in the same area
and it is desired for the entire group to have the same appearance. Ten
levels are available. The factory setting brightness is 8.
Change the brightness by pressing the or button. When the
desired brightness has been selected, press the button.
8.10 RS-485 Parameters
These menus will only appear if the RS-485 is enabled (see 8.3). The
factory setting is 8 Bit, no (nOnE) Parity, 1 Stop Bit.
Make selections using the and buttons then press the button
to move to the next menu.
8.11 Cycle Time
The cycle time can be changed using this menu. Please note that
changing this menu will directly affect the volume of reagent
that will be consumed.
Make selections using the and buttons then press the button.
Allowable setting is from 60 to 600 seconds (10 minutes).
NOTICE
The indicator reagent has a defined life after being mixed regardless
of the cycle time setting. If the reagent is kept in the powered cooling
chamber the life is 90 days.
8.12 Water Conservation
To conserve water, the flush time can be adjusted use as little water
as possible.
NOTICE
This feature is generally not used in ballast water applications and
should be set to OFF.
The instrument requires 110 seconds to complete its normal
operations, when the WCON is turned On, at the factory cycle time the
instrument sits idle for about 40 seconds. This results in about a 25%
water savings. The actual amount of water conservation is dependent
on the incoming water pressure and the cycle time setting.
The use of this option may result in some slight loss of accuracy. The
factory setting for this option is OFF.
Make selections using the and buttons then press the button
to exit to AUTO mode and save all configuration settings. If the 4-20
mA in section 7.1 is turned ON, there are two additional menus that will
appear before returning to AUTO mode.
In addition to averaging, the CLX-Ex2 has a software filter that limits
the change between consecutive readings to 20%. For example,
the reading following a reading of 1.00 ppm could not be displayed
as higher than 1.20 ppm or lower than 0.80 ppm. This filter also
helps smooth out large changes and eliminate reading spikes. After
3 consecutive readings, it is assumed that the large change in the
readings is “real”, and the filter will be disabled. For example, the
change between reading 1 and 2, and readings 2 and 3 will be limited
to 20%, but the change between readings 3 and 4 will not be limited.
Note: This software filter is completely disabled when the averaging
(AVG) is set to 1.

16
8.13 4mA Adjustment
If the 4-20 mA setting is turned ON (8.1 Setting the 4-20
mA Output), the following two menus will appear. The first
menu outputs a constant 4 mA while allowing for a small
amount of adjustment. The adjustment can be made using
the and buttons. This adjustment will allow the operator to make
the CLX-Ex2 agree with a PLC or SCADA system. The adjustment
limits are ± 200 counts or about ± 0.2 mA.
This setting will be slightly different on each instrument as each
CLX-Ex2 will be factory set to 4.00mA. Press the button when
adjustments are complete to save this setting and move on to the
20mA adjustment.
8.14 20mA Adjustment
This menu operates similar to the previous menu. This menu outputs a
constant 20 mA while allowing for a small amount of adjustment. The
adjustment can be made using the and buttons. The adjustment
limits are ± 1000 counts or about ± 1 mA.
This setting will be slightly different on each instrument as each CLX-Ex2
will be factory set to 20.00mA.
When complete with the 20mA adjustment, press the button to exit
to AUTO mode and save all configuration settings.
9.0 Additional Features and
Options
9.1 RS-485 Outputs
The CLX-Ex2 has the capability to operate in two different RS-485
modes. Included are a simple communication mode and Modbus
communications. Both modes will automatically configure and do not
require any changes or selections.
9.1.1 Simple Communication
The CLX-Ex2 can provide basic communications over simple programs
such as the Hilgraeve HyperTerminal that is included with most
Microsoft Windows packages. The user could also use Visual Basic
or other programs. The factory setting communication
parameters are 8 bits, no parity and 1 stop bit. These can
be changed in the Extended CONFIG menus 8.9 RS-485
Parameters.
The master computer will send out:
• Byte #1 the attention character “:” in ASCII or 3A Hex
• Byte #2 the address of the CLX-Ex2 being queried
• Byte #3 & 4 CR LF or 0D 0A in hex
The CLX-Ex2 will respond with:
• The same attention character “:” in ASCII or 3A Hex
• The address of the CLX-Ex2
• The Reading
• The Unit (mg/L)
A sample communication would look like this:
(Master computer requesting a report
from address #1) :1 CRLF
(CLX-Ex2 set to address #1 Response) :001 0.0249mg/L
9.1.2 Modbus Communication
Modbus protocol communication is included with this instrument.
The Modbus address list is available from HF scientific or online at
www.hfscientiifc.com.

17
Please note that these operating screens cannot be seen
except through the door window with the cabinet door
closed or in maintenance bypass mode. See section 5.3
for more information on this.
The CLX-Ex2 performs continuous diagnostic monitoring. In the
CLX-Ex2, there are 4 severity levels of fault detection. Level 4, 3 and
2 will allow normal operation, but warn of the problem. Level 1 is an
instrument failure and the instrument will not operate. Any faults are
displayed in a queue form in the bottom row of the LCD.
A level 4 fault is simply a screen indication that one of the alarm levels
has been activated. This fault level will not affect the 4-20 mA and will
only affect the alarm activated. The sample back light blinks at a rate of
once every 4 seconds.
A level 3 fault indicates a failure or a problem that usually can be
corrected by the operator. Refer to the chart below. If any of these
errors occur, the instrument will still display readings and probably
will operate correctly. These faults will self-clear when the problem is
corrected. If any of these faults occur, they may affect the 4-20mA and
any alarm dependent on the detection setting (Error). See sections 8.2
and 8.4.1 for error settings. The sample back light blinks at a rate of
once every 2.5 seconds to indicate these faults.
Level 3 (Self-Clearing) fault conditions
Message Description of Fault Corrective Action
MA 4-20 mA enabled and loop open Check 4-20 mA wiring or turn off 4- 20mA
if not used
CAL Calibration invalid –not accepted Recalibrate if needed
WATR No water flowing Check water flow
FAST Intake water flow too fast Set flow rate (see section 10.2)
SLOW Sample cuvette filling too slowly Set flow rate (see section 10.2)
PURG Sample cuvette has slow purge Check drain lines
NPRG Sample cuvette not purging Check drain lines
ISOL Problem with intake solenoid Check wiring, check for clogged solenoid
PSOL Problem with purge solenoid Check wiring, check for clogged solenoid
GLAS Dirty cuvette Replace or clean cuvette
WCAL Water Level Calibration Invalid Clear fault (see section 10.3)
A level 2 fault indicates a severe problem that will usually
require technical assistance from HF scientific customer
service (see section 10.6). The queued display will show
POST. If this fault occurs it will affect the 4-20mA and any
alarm set for fault detection (Error). The sample back light blinks at rate
of once every 1 second.
A level 1 fault is a system fault. This is NOT a problem that
the operator can correct, and the unit must be returned
to the factory for service (see section 10.6). These failures
consist of failures in the CPU, A/D, EEPROM or other
devices internal to the instrument. The queued display will
show FAIL, the upper display will show a four or five digit fault code.
If this fault occurs, it will affect the 4-20mA and any alarm set for fault
detection (Error). The instrument will not operate with this fault. The
sample back light blinks at rate of once every 0.4 seconds.
If any fault condition occurs, the message indicating the fault will be
shown on the lower row of the display.
10.2 Setting Flow Rate
The flow rate on the CLX-Ex2 was factory adjusted and usually should
not need adjustment. Installation variances may affect the flow. The
optimal flow rate through the CLX-Ex2 may be adjusted if needed.
The flow is adjusted by removing regulator vinyl cap and turning the
adjustment screw on the pressure regulator. To assist in this adjustment
follow the procedure shown below:
1. Press the SERVICE button.
2. Wait for the display to read HOLd, then press Mode/ Exit.
3. Display will show FLOW with the number 0. Press either the or 
button.
4. CLXB will drain, and then pulse in water while a count is displayed
on the screen.
5. The display will show one of three messages HI, LO or Good.
The flow test determines if the flow rate is suitable for proper operation.
Loosen the locking nut then adjust the pressure regulator using a coin
or a large flat blade screwdriver. Press either the or button while
in the FLOW routine to display a new flow rate. Please note that only ¼
turn incremental adjustments should be made to the regulator on
each attempt.
If the message is LO, turn the regulator control clockwise. If the
message is HI, turn the regulator counterclockwise. If the message
is Good, no adjustment is required. Tighten the locking nut after
adjustment and replace the regulator vinyl cap. To return to normal
operation, press the button.
10.3 Clearing Faults
Every time SERVICE mode is exited, all faults are cleared. If the original
fault or a new fault occurs, it will be posted.
In the case of WCAL, it is possible the power was enabled before a
water sample was available. Ensure a water sample is available and
then press PRIME to force another Water Calibration (WCAL).
10.4 Reagent Clogs
If reagents fail to flow or Prime it may be due to a clog in
either the tubing or at a check valve. To alleviate this you
may have to flush the system with Chlorine Free water,
preferably Deionized water. See section11.4 Check Valve
Flushing Kit.
Only access when the atmosphere has been tested and known to
be safe.
WARNING
!
10.0 Troubleshooting
10.1 CLX-Ex2 Fault Detection

18
Symptom Cause Cure
Lower display shows MA 4-20 mA loop open Check wiring. See sections
4.4.4 and 8.1
Lower display shows FAIL Major system fault Refer to section 10.1
Readings are erratic (1) Bubbles in solution
(2) Debris in flow
(3) Bad or sticky check valves
(1) See above
(2) Install T strainer at inlet
(3) Flush check valves as
described in section 10.4
or replace the valves
Readings are lower than
expected
(1) Condensate or leaky
measurement cuvette
(2) Measurement cuvette dirty
(3) Reagents bad or expired
(4) Buffer reagent not being
dispensed
(1) Install desiccant cartridge
kit
(2) Replace or clean cuvette
(3) Replace reagents
(4) Check buffer lines and
check valves
Upper display flashes Sample Over-Range Check sample. Sample may
be too high to read
Upper display shows
nOnE while attempting
to calibrate
No current reading displayed Wait for CLX-Ex2 to post a
reading
10.5 Diagnostic Chart
10.6 Technical and Customer Assistance
If for any reason assistance is needed regarding this instrument please
do not hesitate to contact either the HF scientific Technical Service
Department or the HF scientific Customer Service Department:
HF scientific
16260 Airport Park Drive, Suite 140
Fort Myers, FL 33913
Phone: [phone]
Toll Free: 888-203-7248
Fax: [phone]
Email: [e-mail]
Website: www.hfscientific.com
11.1 Maintenance Schedule
The recommended schedule is shown below. It is important to replace
the reagents to get reliable accurate readings from the CLX-Ex2.
The Buffer supplied can last for up to one year. Each mixed indicator
reagent will last for up to 90 days* when kept special cooling chamber.
The one year kit includes one buffer bottle and four sets of indicator
reagents. The Buffer reagent is mounted in a clip and is further held
with a Velcro strap. The indicator reagent is in a 125ml bottle mounts
inside an insulator and also mounts in a clip with a Velcro security
strap. See section 11.2 for more information on the reagents.
The CLX-Ex2 is shipped with one CLX-Ex2 Tubing/Cuvette kit, HF part
#09950EX. The kit consists of the following:
Qty Part
1Spare Buffer Cap Assembly
1Spare Indicator Cap Assembly
8Pump Tubes
1Spare Cuvette
Two replacement sets of reagent cap/tubing assemblies are supplied
with the CLX-Ex2; one for the buffer and one for the indicator.
Additional kits can be ordered from your local HF scientific distributor or
representative. It is recommended to keep one kit on hand at all times.
Generally, both pump tubes should be replaced annually. Spare cap
assemblies for both the buffer and the indicator are supplied and can
be replaced when needed.
Every 90 days
1. The indicator reagent required for operating this instrument must be
changed at least every 90 days. The buffer reagent can be used up
to one year.
2. The internal strainer should be checked and cleaned if necessary.
3. The glass cuvette should be inspected. Check for excessive debris
on the inside surface of the glass. It is suggested to keep a spare
cuvette to replace when required. The old cuvette may be cleaned, if
possible, for future replacement.
Flushing the System
Press the SERVICE button to stop the water flow. Remove old reagents
and discard. Place the suction tubes in a small container of clean
water. Press SERVICE to return to operation mode, press PRIME and
then to flush the system with water. Remove the suction tubes from
the water Press PRIME and then to remove most of the water.
NOTICE
After a PRIME the CLX-Ex2 will perform a water calibration (WCAL).
It will take a few minutes to complete this procedure.
*The 1 year buffer and 90 day indicator reagent life is primarily used on
ballast water applications. The assumption is based on the factory default
of a 60 second cycle and up to 60 hours total operation per month.
Only access when the atmosphere has been tested and known to
be safe.
WARNING
!
11.0 Routine Maintenance
Please note that to perform these maintenance
operations the cabinet door must be open and the
instrument in maintenance bypass mode. See section
5.3 for more information on this.
Specific condition of use: Parts of the enclosure are non-conducting
and exceed the maximum permissible resistance according to the IEC
60079-0. Therefore, to avoid electrostatic charge build-up, it must not
be rubbed or cleaned with solvents or a dry cloth when installed/used
within a potentially explosive atmosphere.
NOTICE

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Pump Tubing Replacement
The black pump tubes may need replacement more often due to the
fact that they are subject to wear. The inline check valves should not
need to be replaced and should be saved. Please note that the check
valves are directional as shown below.
Figure 5: Inline check valve
Steps:
1. Flush the system as described above to reduce personal contact
with the reagents.
2. Press SERVICE to stop the flow of sample water and drain the
cuvette.
3. Remove and retain the thumb screw on top of the pump; pull the
pump hammer and spring up and out of the way. There is no need
to completely remove the hammer and spring.
4. Working on one reagent side at a time. Replace the black tubing
between optics inlet and the check valve OUTLET. Discard the old tubing.
5. Ensure the check valve is placed into its seat.
6. Repeat steps 4 and 5 for the other reagent.
7. Replace the hammer and spring back into place and secure with the
thumb screw.
8. Check the drawing on the following page to ensure correct installation.
9. Return to operation as described.
Cap Assembly Replacement
When the Cap Assemblies needs to be changed follow the procedure
shown below. It is recommended that both assemblies are changed at
the same time.
Steps:
1. Flush the system as described above to reduce personal contact
with the reagents.
2. Press SERVICE to stop the flow of sample water and drain the
cuvette.
3. Replace the buffer cap (blue or black cap) assembly.
4. Repeat step 3 above, for the indicator side (white cap).
5. Replace reagents, prime and return to service.
Cuvette Replacement
Check the condition of cuvette and change if it appears badly soiled or
discolored. Follow the steps below.
Steps:
1. Replace the two Cap Assemblies.
2. Turn the knurled top on the optics system counterclockwise (as
viewed for the top) until the cuvette just “pops” out, but do not
remove the top.
3. When the cuvette “pops” out, move the retaining O-ring and remove
the cuvette. You may need a stiff wire such as a bent paper clip
to grasp the cuvette. Retain this cuvette for future use if it can be
cleaned.
4. Install the new cuvette by pushing it firmly in place and turning the
knurled top clockwise until the cuvette is held securely.
5. Check the drawing on the following page to ensure correct installation.
6. Return to operation as described.
T-Strainer Cleaning
The T-strainer is integral to the
instrument and must be checked
occasionally. When necessary it
must be removed and cleaned.
The strainer screen may require
replacement after a period of time.
Steps:
1. Press SERVICE to stop the flow
of sample water and drain the
cuvette.
2. Ensure the source water is
turned off.
3. The T-strainer is clamped to the
intake regulator. The removal
requires the use of a flat blade screwdriver as shown in the photo.
Once the two clamps are opened the T-strainer can be removed.
4. Disconnect the top of the T-strainer and regulator from the tubing
and clear of the enclosure.
5. Remove and clean
the screen and then
reassemble.
6. Be sure to tighten the
bowl of the strainer.
7. Be certain the clamps
are tightened fully and
the tubing connections
are complete. You may
require pliers to close
the clamps.
8. Turn source water back on.
9. Return to normal operation.
10. Check for any leaks.
Return to Normal Operation
Press the SERVICE button to return sample flow to the system.
Check for leaks. If a leak occurs press SERVICE again, repair leak and
try again. Once the system is operating correctly, return or replace
reagents and press PRIME and then one time to restart reagent flow.
The system will automatically return to normal operation.
NOTICE
Tubes may darken due to contact with the reagent. This condition
does not affect the performance of these parts.
11.2 Replacing or Installing the Reagents
Reagent kits are available from HF scientific for Total
Chlorine Refer to section 12.0 Replacement Parts and
Accessories for the appropriate Catalog number. There are
two reagents required, for the instrument to operate; the
buffer and the indicator.
The reagents are provided “wet” and the buffer is ready to use and will
last up to one year.
The smaller indicator reagent does require the addition of the DPD
power to activate it. Once activated it starts to oxidize. This process is
slowed by keeping it in the cooling chamber.
NOTICE
When commissioning the CLX-Ex2 it is recommended to follow
the procedure in section 11.4. This procedure only needs to be
done once when the instrument first commissioned.

20
11.3 Indicator Reagent Preparation
Remove the cap of the small liquid indicator reagent and add the
contents of the DPD powder bottle (small brown bottle). Cap and shake
to fully dissolve the powder.
NOTICE
Once mixed the indicator has an expected life of 90 days if kept
in the powered cooling chamber. Write the mixing date on the
reagent bottle labels in the area provided.
Dispose of expired reagents correctly.
To replace the reagents, press the SERVICE button; this will empty the
cuvette and stop any flow of water. Remove the cap on both bottles
replace with the cap supplied with the CLX-Ex2. The buffer is installed
on the left and the indicator is installed in the cooling chamber. The
suction tube for both reagents will reach the bottom of the bottles.
To complete the replacement procedure, press the PRIME button
and then the button. This will draw enough of each reagent to
completely prime the tubes and replace any old solution. The system
will automatically return to normal operation after it has primed.
NOTICE
Use caution when changing the reagents as they are corrosive.
These reagents may stain clothing. After changing the reagents,
operators should wash their hands.
11.4 Check Valve Flushing Kit
Sometimes upon initial commissioning, the check valves stick
and require manual priming. This should not be needed after
commissioning. Be careful when using this kit to use only chlorine free
water. Complete instructions are included in the kit.
Figure 6: Check Valve Flushing
11.5 Instrument Storage
If the CLX-Ex2 is relocated or will be inactive for long
periods of time (several months), remove the reagents.
Flush the reagent system as describe in 11.1 Maintenance
Schedule. Place the instrument in Service mode to drain the
system then remove power by disconnecting the mains power plug. It
is usually a good idea to disconnect or shut off the source water.
11.6 Cleaning the CLX-Ex2
Flush the system as mentioned in section 11.1 Maintenance
Schedule. When the flushing is finished, press the SERVICE
button wait until the display reads HOLd.
As a matter of safety, always disconnect any power source
to the CLX-Ex2 prior to attempting any cleaning. It is recommended
that the source water is also shut off.
Isopropyl alcohol (rubbing alcohol) on a soft cotton cloth works very
well in removing reagent stains from plastic parts, the key pad and the
display. Use care when cleaning around electrical components. Do
not use any harsh cleaning agents as these may cause damage to the
instrument components.
Ensure that the system is dry prior to applying power.