Walchem WDIS Series User manual

WDIS Series Disinfection Controller
Instruction Manual
Walchem Corporation Five Boynton Road Hopping Brook Park Holliston, MA 01746 USA
TEL: [phone] FAX: [phone] WEB: www.walchem.com
W A L C H E M
W
DIS Controllers

Notice
©2008 WALCHEM Corporation
5 Boynton Road, Holliston, MA 01746 USA
[phone]
All Rights Reserved
Printed in USA
Proprietary Material
The information and descriptions contained herein are the property of WALCHEM
Corporation. Such information and descriptions may not be copied or reproduced by any
means, or disseminated or distributed without the express prior written permission of
WALCHEM Corporation, 5 Boynton Road, Holliston, MA 01746.
This document is for information purposes only and is subject to change without notice.
Statement of Limited Warranty
WALCHEM Corporation warrants equipment of its manufacture, and bearing its identification
to be free from defects in workmanship and material for a period of 24 months for electronics
and 12 months for mechanical parts and electrodes from date of delivery from the factory or
authorized distributor under normal use and service and otherwise when such equipment is
used in accordance with instructions furnished by WALCHEM Corporation and for the
purposes disclosed in writing at the time of purchase, if any. WALCHEM Corporation's liability
under this warranty shall be limited to replacement or repair, F.O.B. Holliston, MA U.S.A. of
any defective equipment or part which, having been returned to WALCHEM Corporation,
transportation charges prepaid, has been inspected and determined by WALCHEM
Corporation to be defective. Replaceable elastomeric parts and glass components are
expendable and are not covered by any warranty.
THIS WARRANTY IS IN LIEU OF ANY OTHER WARRANTY, EITHER EXPRESS OR
IMPLIED, AS TO DESCRIPTION, QUALITY, MERCHANTABILITY, FITNESS FOR ANY
PARTICULAR PURPOSE OR USE, OR ANY OTHER MATTER.
P/N 180318.D
Feb 2008

Table of Contents
1.0 Introduction.....................................................................................................................................1
2.0 Specifications..................................................................................................................................1
2.1 Measurement Performance (Sensors)..........................................................................................................1
2.2 Electrical: Input/Output .................................................................................................................................2
2.3 Mechanical (Controller).................................................................................................................................2
3.0 Unpacking and Installation............................................................................................................3
3.1 Unpacking the unit.........................................................................................................................................3
3.2 Mounting the electronic enclosure...............................................................................................................3
3.3 Installation......................................................................................................................................................3
Assembling the Sensor....................................................................................................................................3
Flow Cell Placement ........................................................................................................................................4
Installing Sensor into Flow Cell........................................................................................................................4
3.4 Icon Definitions..............................................................................................................................................5
3.5 Electrical Installation.....................................................................................................................................8
4.0 Function Overview........................................................................................................................12
4.1 Front Panel ...................................................................................................................................................12
4.2 Display..........................................................................................................................................................12
4.3 Keypad..........................................................................................................................................................13
4.4 Access Code ................................................................................................................................................13
4.5 Startup ..........................................................................................................................................................13
Initial Startup..................................................................................................................................................13
Normal Startup...............................................................................................................................................14
4.6 Shutdown......................................................................................................................................................14
5.0 Operation.......................................................................................................................................14
5.1 Main Menu ....................................................................................................................................................14
5.2 Sensor Menu ................................................................................................................................................16
Cal'd...............................................................................................................................................................16
Calibration......................................................................................................................................................16
Zero Calibration..............................................................................................................................................16
Days Btwn Cal ...............................................................................................................................................16
Input...............................................................................................................................................................18
Self Test.........................................................................................................................................................18
Sensor Type...................................................................................................................................................18
5.3 Control 1 and Control 2 Menus...................................................................................................................18
Hi/Lo Set Point...............................................................................................................................................18
Dead Band.....................................................................................................................................................18
Time Limit ......................................................................................................................................................18
Interlock .........................................................................................................................................................18
Control Dir......................................................................................................................................................19
HOA...............................................................................................................................................................19
5.4 Auxiliary 1 and 2 Menu................................................................................................................................21
Mode..............................................................................................................................................................21
Lo Alarm Pt ....................................................................................................................................................21
Hi Alarm Pt.....................................................................................................................................................21
Dead Band.....................................................................................................................................................21
Probe Wash Sched........................................................................................................................................22
Hold Time.......................................................................................................................................................22
HOA...............................................................................................................................................................22
5.5 4-20 mA Menu (Optional).............................................................................................................................24
4 mA Pt..........................................................................................................................................................24
20 mA Pt........................................................................................................................................................24
Calibrate.........................................................................................................................................................24
Fixed 4 mA Out..............................................................................................................................................24
Fixed 20 mA Out............................................................................................................................................24
5.6 Clock Menu...................................................................................................................................................25
Set Clock........................................................................................................................................................25
5.7 Access Code Menu......................................................................................................................................26
Enable Y/N.....................................................................................................................................................26

New Access Code..........................................................................................................................................26
6.0 Maintenance..................................................................................................................................28
6.1 Sensor Maintenance....................................................................................................................................28
Cleaning the Membrane.................................................................................................................................28
Replacing the Membrane...............................................................................................................................28
6.2 Replacing the Fuses....................................................................................................................................29
7.0 Troubleshooting ...........................................................................................................................29
7.1 Error Messages............................................................................................................................................29
Calibration Time.............................................................................................................................................29
Cal Failed.......................................................................................................................................................29
Sens Low No Cal ...........................................................................................................................................29
Probe Error No Cal.........................................................................................................................................29
Bad Zero Cal Fail...........................................................................................................................................30
Output Timeout ..............................................................................................................................................30
High Alarm.....................................................................................................................................................30
Low Alarm......................................................................................................................................................30
Out Range Alarm ...........................................................................................................................................30
In Range Output.............................................................................................................................................30
Probe Error ....................................................................................................................................................31
Interlock .........................................................................................................................................................31
Check Set Points............................................................................................................................................31
8.0 Service Policy ...............................................................................................................................31

1
1.0 Introduction
The Walchem WDIS Series controllers are wall mount disinfection controllers that provide two relays
used to perform on/off control of chlorine, chlorine dioxide, ozone or Peracetic acid. Two additional
relays are available for use as alarms or probe washing. A fifth output is used as a diagnostic alarm.
An isolated 4-20 mA output is optional.
They are only compatible with Walchem sensors. The choice of the type of sensor is selected through
the keypad. The sensors are temperature compensated internally; no temperature signal is transmitted
to the controller. The controller will prompt you to calibrate the sensor at the desired frequency.
2.0 Specifications
2.1 Measurement Performance (Sensors)
Chlorine Dioxide Peracetic
Acid Ozone Chlorine
Range 0-10 mg/l 0-1000 mg/l 0-10 mg/l 0-10 mg/l
Resolution 0.01 mg/l 1 mg/l 0.01 mg/l 0.01 mg/l
Cross Sensitivity Free Chlorine (5%),
Ozone
Free Chlorine
(5%)
Bromine, Ozone, Iodine,
ClO2, Di-/Trichloramine, or
Bromamine
Flow Rate of Sample 30 to 100 liters/hour (0.13 to 0.44 gallons/minute)
pH Range of Sample 1.0 – 14.0 6.8 – 8.0 (7.2 to 7.4 ideal)
Conductivity Range of Sample 50 to 10,000 μS/cm Up to 4% NaCl
Response Time 30 sec 3 min 30 sec 30 sec
Electrical
Power Requirements ± 5 VDC, 5 mA maximum
Signal 0 to -1000 mVDC
Maximum Cable Length 1000 ft (305 m)
Cable Required 2 twisted pair, 22 AWG, shielded, 35 pF/ft (Walchem 100084 or Belden 8723)
Mechanical
Operating Temperature 0 to 50°C (41 to 122°F) 0 to 45°C (41 to 113° F)
Operating Pressure 0 to 1 atm (0 to 14.7 psi)
Storage Temperature 0 to 50°C (41 to 122°F)
Shelf Life 1 year
Flow Cell Inlet ¼” NPTF
Flow Cell Outlet ¾” NPTF
Wetted Materials of Construction
Sensor Body PVC, Polycarbonate
Membrane Silicone PTFE
Flow Cell Body Isoplast
O-Ring FKM

2
2.2 Electrical: Input/Output
Input Power (Controller) 110-120VAC or 220-240VAC
50/60 Hz, 10A or 50/60 Hz, 5A
Input Signal
Controller Sensor Input ±1400 mV
Interlock (optional) Isolated dry contact closure required (i.e., flow, level, etc.)
Output
Control 1/2 (ON/OFF)
Internally powered relays
@ 120 VAC, 10 A resistive, 1/8 HP @ 240 VAC, 6A resistive, 1/8 HP
AUX1, AUX2, Alarm
Dry contact relays
@ 120 VAC, 10A resistive, 1/8 HP @ 240 VAC, 6A resistive, 1/8 HP
Note: The Alarm relay is non-programmable. Refer to the Main Menu diagram on page 14 for the list of error conditions
that trigger the alarm relay.
4-20 mA (optional) Fully isolated, internally powered
600 Ωmax. resistive load
Resolution .001% of span
Accuracy ±1% of reading.
Sensor Power ±5 VDC, 5 mA
(supplied by controller)
Agency Approvals UL ANSI/UL 61010-1:2004, 2nd Edition*
CAN/CSA C22,2 No.61010-1:2004 2nd Edition*
CE Safety EN 61010-1 2nd Edition (2001)*
CE EMC EN 61326 :1998 Annex A*
Note: For EN61000-4-6,-3 the controller met performance criteria B.
*Class A equipment: Equipment suitable for use in establishments other than domestic, and
those directly connected to a low voltage (100-240 VAC) power supply network which
supplies buildings used for domestic purposes.
2.3 Mechanical (Controller)
Enclosure Material Polycarbonate
NEMA Rating NEMA 4X
Dimensions 8.5" x 6.5" x 5.5"
Display 2 x 16 character backlit liquid crystal
Operating Ambient Temp 32 – 122°F (0 – 50°C)
Storage Temperature -20 – 180°F (-29 – 80°C)
Shipping Weight 7 lbs (3kg) approximately

3
3.0 Unpacking and Installation
3.1 Unpacking the unit
Inspect the contents of the carton. Please notify the carrier immediately if there are any signs of
damage to the controller or its parts. Contact your distributor if any of the parts are missing. The
carton should contain a WDIS controller and instruction manual. Any options or accessories will be
incorporated as ordered.
3.2 Mounting the electronic enclosure
The WDIS series controller is supplied with mounting holes on the enclosure. It should be wall
mounted with the display at eye level, on a vibration-free surface, utilizing all 4 mounting holes for
maximum stability. Use M6 (1/4" diameter) fasteners that are appropriate for the substrate material of
the wall. The enclosure is NEMA 4X rated. The maximum operating ambient temperature is 122°F
(50°C). The enclosure requires the following clearances:
Top: 2"
Left: 8"
Right: 4"
Bottom: 7"
3.3 Installation
Once the enclosure is mounted, the metering pumps may be located at any distance from the
controller. The sensor may be placed up to 1000 feet (305m) from the controller. Shielded cable with
twisted pairs is required. Always route AC voltage wiring in conduit that is separated by 6 inches
from low voltage DC signal lines (such as the sensor signal).
Assembling the Sensor
CAUTION: Wear gloves and safety glasses during assembly of the sensor since the
electrolyte is a STRONG ACID. It is recommended to perform this operation over a sink with
running water available. After using, re-cap any remaining electrolyte until the next use.
1. Remove the black protective tube from the electrode tip, and clean just the tip of the working
electrode with the special abrasive paper supplied. Avoid touching the electrodes! Hold the pad
with the special abrasive paper and rub the electrode tip over it, holding the electrode at a slight
angle. Repeat several times at different angles.
2. Open the vial containing the membrane cap. Empty out the water. Make sure that only one gray
band is in the groove covering the vent hole in the membrane cap. Fill the membrane cap to the
top with the electrolyte fill solution. (The free chlorine membrane cap is shipped dry, and has only
one band)
3. Hold the sensor body vertically with the tip pointing down and SLOWLY screw on the membrane
cap until it is hand tight. Be prepared for some electrolyte solution to squeeze out from the
vent hole in the cap.
4. Push the second gray band into the groove in the cap, making sure that the bands are smooth and
flush.
5. Rinse your hands, the sensor, and all surfaces contaminated with electrolyte solution with running
water. Check the sensor for leaks, especially at the membrane and the membrane cap threads. If
any leaks are detected, tighten the membrane cap or replace it.

4
6. Push the cable onto the end of the sensor, aligning the pins with the holes. Turn the connector
until hand tight to seal the cable connection.
Flow Cell Placement
Instructions for mounting the sensor into the process can vary greatly with the circumstances that are
encountered in your application. Here are some general guidelines to assist you. Refer also to the
typical installation drawings.
The sensor should be mounted such that the measuring surfaces will always stay wet. If the membrane
dries out, it will respond slowly to changing disinfectant values for 24 hours, and if dried out
repeatedly, will fail prematurely.
The flow cell should be placed on the discharge side of a circulation pump or downhill from a gravity
feed. Flow into the cell must come from the bottom side that has the ¾” x ¼” NPT reducing bushing
installed. The reducing bushing provides the flow velocity required for accurate readings and
must not be removed!
A “U” trap should be installed so that if the flow stops, the sensor is still immersed in the water. The
outlet of the flow cell must be plumbed to open atmosphere unless the system pressure is at or below
1 atmosphere. If the flow through the line cannot be stopped to allow for cleaning and calibration of
the sensor, then it should be placed in a by-pass line with isolation valves to allow for sensor removal.
Install the sensor vertically, with the measuring surface pointing down, at least 5 degrees above
horizontal. (Refer to Installation drawings)
Flow rate regulation must be done upstream from the sensor, because any flow restriction downstream
can increase the pressure above atmospheric and damage the membrane cap!
The sensor should be installed in an area where there is good solution movement and where it will
respond rapidly to chemical additions. The placement of the sensor relative to the placement of
chemical replenishment, along with the quality of the mixing, and the replenishment chemical flow
rate are critical to accurate process control.
Installing Sensor into Flow Cell
1. Assemble the flow cell as shown below from the top down. The reducer should already be
installed in the flow cell body.
2. Slide the 102586 nut over the membrane end of the sensor, followed by the 103419 top washer,
followed by the 103422 o-ring, followed by the 103419 bottom washer (concave side up),
followed by the 103421 clip ring. The clip ring must be pushed up until it snaps into the groove in
the sensor body.
3. Place the 102594 o-ring in the top o-ring groove of the 102881 flow cell body.
4. Place the sensor body into the flow cell body, and tighten the 102586 nut until it is hand-tight.
Before tightening completely, pull the sensor up until the clip ring is up against the bottom
washer.
5. Insert the 191303 cable into the connector at the top of the sensor. The connector is keyed and
will only insert in one orientation.

5
3.4 Icon Definitions
Symbol Publication Description
IEC 417, No.5019 Protective Conductor
Terminal
IEC 417, No. 5007 On (Supply)
IEC 417, No. 5008 Off (Supply)
ISO 3864, No. B.3.6 Caution, risk of electric shock
ISO 3864, No. B.3.1 Caution
Nut, P/N 102586
Body, P/N 191279-R
O-Ring, P/N 102594
Sensor, P/N 191280 (WCDB)
191300 (WFCB)
191320 (WOZB)
191338 (WPAB)
Clip Ring, P/N 103421
Washer Set, P/N 103419 O-Ring, P/N 103422
Clip Ring Groove
Membrane Cap, P/N 103423 (WCDB)
103463 (WFCB)
103498 (WOZB)
103499 (WPAB)
Cable, P/N 191303

6
ISOLATION
VALVE
(NORMALLY
OPEN)
1
2
3
4
5
6
7
8
9
10
1/4"
NPT
ROTAMETER
30-100 LPH
RECIRCULATION
PUMP
FROM
PROCESS
20 FT
(6M)
3/4"
NPT
TO
PROCESS
Figure 1 Typical Installation

7
Typical Installation Using Walchem Manifold
Sample Valve
Flow Control Valve
Water In
Water Out
To Open Atmosphere
Rotameter
Flow Cell
Flow Switch
Sensor

8
3.5 Electrical Installation
Based on the model number, the following voltages are required:
WDIS3xx-1xx 120 VAC, 50/60 Hz, prewired
WDIS3xx-4xx 120 VAC, 50/60 Hz, hardwired
WDIS3xx-5xx 240 VAC, 50/60 Hz, hardwired
The various standard wiring options are shown below. Your WDIS series controller will arrive from
the factory prewired or ready for hardwiring. Depending on your configuration of controller options,
you may be required to hardwire some or all of the output devices. Refer to figures 2, 3 and 4 for
circuit board layout and wiring.
Note: When wiring the optional 4-20 mA output or a remote flow switch, it is advisable to use
stranded, shielded, twisted pair wire between 22-26 AWG. Shield should be terminated at the
controller ground stud (see figure 4).
CAUTION
1. There are live circuits inside the controller even when the power switch on the front panel is in
the OFF position! The front panel must never be opened before power to the controller is
REMOVED!
If your controller is prewired, it is supplied with a 8 foot, 18 AWG power cord with USA
style plug. A tool (#1 Phillips driver) is required to open the front panel.
2. When mounting the controller, make sure there is clear access to the disconnecting device!
3. The electrical installation of the controller must be done by trained personnel only and
conform to all applicable National, State and Local codes!
4. Proper grounding of this product is required. Any attempt to bypass the grounding will
compromise the safety of persons and property.
5. Operating this product in a manner not specified by Walchem may impair the protection
provided by the equipment.

9
Figure 2 Conduit/Wiring Options
Power CTRL 2 CTRL 1
Supply
Alarm AUX 1 AUX 2
Inputs
Outputs
Optional
Input 4-20 mA (optional)
Side View Bottom View
Optional
Input Sensor Input
WDIS Prewired Option
Bottom View
4-20 mA Output Optional Optional Sensor
(optional) Input Input Input
Strain Reliefs (230 VAC) or Holes for
Hardwiring of Input Power and Control Devices
Hardwired Option WDIS

10
NEU NEUTRAL HOT
F2
TB3
TB2
F1
(Grounding
Stud)
INPUTS
+
_
4-20mA
(Optional 4-20 mA Board)
COM PH+
FLOW
SWITCH FM
To Grounding
Stud
-5
WFCB
WCDB
WOZB
WPAB
FRONT PANEL POWER SUPPLY
WHT
RED
BLACK
Figure 3 Wiring to Sensor

11
Figure 4 WDIS310 Output Wiring
Note: The Alarm relay is
non-programmable. Refer
to the Main Menu diagram
on page 14 for the list of
error conditions that
trigger the alarm relay.

12
4.0 Function Overview
4.1 Front Panel
4.2 Display
A summary screen is displayed while the WDIS controller is on. This display shows a bar graph of the
oxidizer process value relative to the set points, a digital display of the process value, and the current
operating conditions.
Towards the center of the bar graph are the (S)'s, which represent the set points. The bar graph grows
from the left hand side, and the point furthest to the right indicates where the process value is relative
to the set points.
The bottom line of the summary screen displays the following potential status messages: Probe Error,
Calibration Time, Output Timeout, High/Low Alarm, Range Alarm, In Range Output, Output1 On,
Output2 On, Probe Wash, Probe Wash Hold, Normal and Interlock.
Summary Screen
DISINFECTION CONTROLLER
CTRL 1 AUX 1 CTRL 2 AUX 2
NEXTPREV.
EXIT ENTER
O
n
/O
ff Power
S
witch
Backlit LCD Display
Output LEDs
Setting Adjustment Keys
Menu/Function Keys

13
4.3 Keypad
The keypad consists of 4 directional arrows and 4 function keys. The arrow keys are used to move the
adjustment cursor and change settings, while the function keys are used to enter values, and navigate
the various menu screens. The function keys are ENTER, EXIT, NEXT and PREV (previous). Use the
NEXT and PREV keys to scroll through the various menu choices. ENTER is used to enter a submenu
and to enter a value. EXIT is used to back up one menu level. If you are at the main menu level, EXIT
will return you to the summary screen.
To change a value in a submenu, the left/right arrow keys move the cursor left and right to each digit
or option that can be changed. The up/down arrows will change numeric values up or down, or scroll
through option choices. Press ENTER only when you have finished making ALL of the changes for
that menu screen.
4.4 Access Code
The WDIS series controller is shipped with the access code disabled. If you wish to enable it, see
Section 5.10 for operation. With the access code enabled, any user can view parameter settings, but
not change them. Note that this provides protection only against casual tampering. Use a lock on the
cover latch if you need more protection.
4.5 Startup
Initial Startup
After having mounted the enclosure and wired the unit, the controller is ready to be started.
Plug in the controller and turn "ON" the power switch to supply power to the unit. The display will
briefly show the WDIS model number and then revert to the normal summary screen. Scroll through
the menus and calibrate the sensor, and set the control parameters as detailed in Section 5, Operation.
To return to the summary screen, press the EXIT key until you return to this screen. The controller will
automatically return to this screen after 10 minutes.
Conditioning
The sensor requires conditioning to acclimate the electrodes prior to generating stable readings.
Conditioning consists of installing the sensor in the flow cell, ensuring that the sensor remains wet at
all times and supplying power to the sensor.
The following conditioning times are recommended:
New Sensor: 12-24 hours
After membrane or electrolyte replacement: 1 hour

14
Normal Startup
Startup is a simple process once your set points are in memory. Simply check your supply of
chemicals, turn on the controller, calibrate the sensor if necessary and it will start controlling.
4.6 Shutdown
To shut the WDIS controller down, simply turn off the power switch. Programming remains in
memory.
The sensor must be stored with the measuring surfaces wet. If an extended shutdown will result in
the sensor dehydrating, it must be removed from its position in the process and stored in a clean, dry
place, without electrolyte in the cap. To reinstall, follow the directions in section 3.3.
5.0 Operation
These units control continuously while power is applied. Programming is accomplished via the local
keypad and display.
To view the top level menu, press any key. The menu structure is grouped by inputs and outputs. Each
input has its own setup menu for calibration and unit of measure selection as needed. Each output has
its own setup menu including set points, timer values, direction of control, etc. as needed. After 10
minutes of inactivity in the menu, the display will return to the summary screen. Keep in mind that
even while browsing through the menus, the unit is still controlling.
5.1 Main Menu
The exact configuration of your WDIS controller determines which menus are available as you scroll
through the settings. Certain menus are only available if you select certain options. All settings are
grouped under the following main menu items:
Sensor
Control 1
Control 2
Auxiliary 1
Auxiliary 2
4-20 mA (Only if 4-20 mA option circuit board is installed)
Time
Access Code
The NEXT key travels forward through this list while the PREV key travels backwards through the
list. Pressing ENTER will enter the lower level menu that is currently displayed.

15
Cl2 1.00ppm
Sensor Cl2 1.00ppm
Ctrl 1 A 11:40
Possible Status Screens
* Probe Error
Probe Wash
Probe Wash Hold
* Interlock
* Output Timeout
* Calibration Time
Range Alarm
In Range Output
High/Low Alarm
Output 1 On
Output 2 On
Normal
* These status screens indicate that the diagnostic alarm relay is activated.
Cl2 1.00ppm
Ctrl 2 A 11:40 Cl2 1.00ppm
Aux 1 A OFF
Cl2 1.00ppm
Time Thu 9:12
Cl2 1.00ppm
4-20 mA 15.66 mA
Cl2 1.00ppm
Aux 2 A OFF
Main Menu
Press Enter key to enter menu or submenu.
Press Exit key to exit menu.
After 10 minutes of inactivity the controller will
automaticall
y
return to the summar
y
screen.
NEXTPREV.
ENTEREXIT
OperationLegend
4-20mA menu is only present if
4-20mA option is installed.
S
1.00
Normal
S
Cl2 1.00ppm
Access Code DIS
Main Menu

16
5.2 Sensor Menu
The sensor menu provides the following settings: Calibration history (informational only), 1 point
calibration, zero calibration, sensor type selection, and other sensor setup menus. Each is discussed in
detail below. Refer to the Sensor Menu chart on the next page.
Note: If you are programming the unit for the first time you must set the Sensor Type first, selecting
between Chlorine (CL2), Chlorine Dioxide (ClO2), Ozone, or Peracetic Acid. See below.
Cal'd
Displays the date of the last sensor calibration.
Calibration
Press ENTER to perform a 1 point process calibration of the sensor.
With the sensor installed in the flow cell, and a sample circulating at the normal flow rate, and the
oxidizer concentration at the normal level, press ENTER at the Calibration screen. The display will
show a ppm reading. If this does not match the known ppm as measured by a test kit or titration, use
the arrow keys to change the displayed value and press ENTER.
Cal Successful/Cal Failed
If the sensor response is good, then the display will read "Cal Successful". If the controller cannot
calculate an acceptable slope from that mV reading, it will read "Cal Failed". A failure usually means
that the sensor needs to be cleaned or replaced.
Zero Calibration
This menu is used to calibrate the sensor to read precisely zero in pure water. It should be set at
installation with the sensor in air or pure water. This zero procedure should be repeated if a new
sensor is installed.
Press ENTER to start the zero adjust procedure. When asked “SnsrInPureWater?”, remove the sensor
from the flow cell and dry it off. Alternatively, supply the flow cell with a sample of water without
any oxidizer in it. Use the arrow key to change the “N” to “Y” and press ENTER. You will be asked
to press ENTER when the mV reading on the top line is stable. If the sensor offset was less than ±100
mV, the display will flash “SensorCalSuccess” and return to the Zero Calibration display. You may
now press EXIT.
If the message “BadZero: CalFail” appears, the offset was too large for the software to compensate.
Check to see that the sensor is out of the bath and is dry and that all wiring connections are correct. If
none of these corrects the problem, install a new sensor.
Days Btwn Cal
Use the arrow keys to set the number of days that you would like to go by before recalibrating the
sensor. The controller will prompt you to recalibrate when that time has expired. Setting the number
of days to zero will disable this feature.