Thermo Scientific ALPHA PH 2000D DIFFERENTIAL PH CONTROLLER User manual

Alpha DO 2000 PPG
Processor/Transmitter
Dissolved Oxygen ( ppm / m/L / % )

Preface
This manual serves to explain the use of the Alpha-pH2000D series pH/ORP controller/transmitter. The manual
functions in two ways, firstly as a step by step guide to help the user operate the instrument. Secondly, it serves
as a handy reference guide. This instruction manual is written to cover as many anticipated applications of the
Alpha-pH2000D pH/ORP controller/transmitter. If you have doubts in the use of the instrument, please do not
hesitate to contact the nearest Alpha Authorised Distributor.
The information presented in this manual is subject to change without notice as improvements are made, and
does not represent a commitment on part of Thermo Scientific.
Thermo Scientific cannot accept any responsibility for damage or malfunction of the unit due to improper use of
the instrument.
Copyright © 2006
All rights reserved.

Safety Information
The Controller/ Transmitter shall be installed and operated only in the manner specified in the Instruction manual.
Only skilled, trained or authorized person should carry out installation, setup and operation of the instrument.
Before powering up the unit, make sure that power source it is connected to, is as specified in the top label.
Failure to do so may result in a permanent damage to the unit.
The unit has live and exposed parts inside. If it has to be opened, make sure that the power to the unit is off and
disconnected.
The unit is Fuse protected. In the event the fuse has to be replaced, use only those as specified in the manual.
The degree of protection against electric shock will be achieved only by observance of the corresponding
installation rules.

TABLE OF CONTENTS
1INTRODUCTION ...................................................................................................................................................................1
1.1 AT THE VERY BEGINNING...............................................................................................................................................1
1.2 INTENDED USE..............................................................................................................................................................1
1.3 SAFETY INSTRUCTIONS .................................................................................................................................................2
1.4 PUTTING OUT OF SERVICE /CORRECT DISPOSAL OF THE UNIT.........................................................................................2
2PRODUCT DESCRIPTION ...................................................................................................................................................3
2.1 DESCRIPTION OF UNIT...................................................................................................................................................3
2.2 MEASUREMENT AND CONTROL SYSTEM..........................................................................................................................4
2.3 UNIT OVERVIEW............................................................................................................................................................5
2.3.1 Display Overview...................................................................................................................................................6
2.3.2 Key functions.........................................................................................................................................................6
2.3.3 LED indicators.......................................................................................................................................................7
2.3.4 Security codes.......................................................................................................................................................7
2.3.5 Menu overview ......................................................................................................................................................8
3ASSEMBLY AND INSTALLATION.......................................................................................................................................9
3.1 MOUNTING THE UNIT .....................................................................................................................................................9
3.2 CONNECTION DIAGRAM...............................................................................................................................................10
4NORMAL OPERATION.......................................................................................................................................................11
4.1 MEASUREMENT MODE.................................................................................................................................................11
5CALIBRATION MODE........................................................................................................................................................12
5.1 ENTERING CALIBRATION MODE....................................................................................................................................12
5.2 PHCALIBRATION.........................................................................................................................................................13
5.3 ORP-MVCALIBRATION ...............................................................................................................................................14
5.4 ORP -% CALIBRATION ................................................................................................................................................14
5.5 VIEW ACTUAL ZERO AND SLOPE ...................................................................................................................................15
6SETUP MODE.....................................................................................................................................................................16
6.1 ENTER SETUP MODE...................................................................................................................................................16
6.2 ELECTRODE OFFSET (OFS) SUB-FUNCTION.................................................................................................................17
6.3 SETTING TEMPERATURE (SET °C°F) SUB-FUNCTION.....................................................................................................18
6.4 CONTROL RELAY A/RELAY B(SP1/SP2) SUB-FUNCTION ............................................................................................19
6.5 CONTROLLER (CNTR) SUB-FUNCTION.........................................................................................................................21
6.6 CURRENT OUTPUT 1SUB-FUNCTION............................................................................................................................23
6.7 CURRENT OUTPUT 2SUB-FUNCTION............................................................................................................................24
6.8 WASH RELAY (WASH) SUB-FUNCTION.........................................................................................................................25
6.9 CONFIGURATION (CNFG) SUB-FUNCTION ....................................................................................................................26
6.10 CALIBRATION (CAL) SUB-FUNCTION.............................................................................................................................27
7RELAY MODES ..................................................................................................................................................................28
7.1 VIEW RELAY SET POINTS .............................................................................................................................................28
7.2 MANUAL RELAY MODE .................................................................................................................................................29
8TECHNICAL SPECIFICATIONS.........................................................................................................................................30
8.1 GENERAL SPECIFICATION............................................................................................................................................30
8.2 SET-POINT AND CONTROL FUNCTION –RELAY 1&RELAY 2..........................................................................................30
8.3 WASH FUNCTION –WASH RELAY ................................................................................................................................30
8.4 ALARM FUNCTION –ALARM RELAY..............................................................................................................................31
8.5 TRANSMITTER FUNCTION ............................................................................................................................................31
8.6 VOLTAGE OUTPUT &HOLD FUNCTION SWITCH ............................................................................................................31
8.7 DISPLAY.....................................................................................................................................................................31
8.8 POWER SUPPLY..........................................................................................................................................................31
8.9 ELECTRICAL DATA AND CONNECTIONS.........................................................................................................................31
8.10 MECHANICAL SPECIFICATIONS.....................................................................................................................................31
8.11 ELECTROMAGNETIC COMPLIANCE (EMC) SPECIFICATIONS...........................................................................................32
8.12 ENVIRONMENTAL CONDITIONS.....................................................................................................................................32
9ACCESSORIES...................................................................................................................................................................33
9.1 REPLACEMENT UNIT ...................................................................................................................................................33
9.2 ASSEMBLY ACCESSORIES ...........................................................................................................................................33

10 GENERAL INFORMATION.................................................................................................................................................34
10.1 WARRANTY.................................................................................................................................................................34
10.2 PACKAGING /SCOPE OF DELIVERY...............................................................................................................................34
10.3 RETURN OF GOODS.....................................................................................................................................................34
10.4 GUIDELINES FOR RETURNING UNIT FOR REPAIR ............................................................................................................34
10.5 MAINTENANCE AND CLEANING.....................................................................................................................................34
11 APPENDICES .....................................................................................................................................................................35
11.1 APPENDIX 1–UNIT FUSE AND JUMPER SETTINGS.........................................................................................................35
11.2 APPENDIX 2–PHBUFFER VALUES AT VARIOUS TEMPERATURES ...................................................................................36
11.3 APPENDIX 3–SIMPLE EXPLANATION ON THE FUNCTION OF HYSTERESIS........................................................................37
11.4 APPENDIX 4–GENERAL INSTRUCTIONS CONCERNING CONTROLLER SETTING...............................................................38
11.4.1 Control characteristic of Controllers used as limit value switch.....................................................................38
11.4.2 Control characteristic of P-Controllers as proportional controller...................................................................38
11.4.3 Control characteristic of PI-Controllers as proportional integral controller.....................................................38
11.4.4 Control signal of Pulse length Controllers......................................................................................................39
11.4.5 Control signal of Pulse Frequency Controllers...............................................................................................40
11.5 APPENDIX 5–ABBREVIATIONS USED IN MENU DISPLAYS...............................................................................................41

INTRODUCTION
1.1 At the beginning
We thank you for having purchased the Alpha pH 2000D pH/ORP Controller.
The construction of the pH/ORP Controller employs leading edge technology and complies with safety
regulations currently in force. Notwithstanding this, improper use could lead to hazards for the user or a
third-party, and/or adverse effects on the plant or other equipment. Therefore, the operating
instructions must be read and understood by the persons involved before work is started with the
pH/ORP Transmitter.
This instruction manual identifies safety instructions and additional information by means of the
following symbols:
This symbol draws attention to safety instructions and warnings of potential
danger which, if neglected, could result in injury to persons and/or damage
to property.
This symbol identifies additional information and instructions which, if
neglected, could lead to inefficient operation and possible loss of
production.
The instruction manual must always be stored close at hand, in a place accessible to all people
working with the pH/ORP Controller.
If you have questions, which are not or insufficiently answered in this instruction manual, please
contact your authorized supplier. They will be glad to assist you.
1.2 Intended Use
The Alpha pH 2000D pH/ORP Controllers are intended solely for pH or ORP and temperature
measurement, as described in this instruction manual.
Any other use, or use not mentioned here, that is incompatible with the technical specifications is
deemed inappropriate. The operator is solely responsible for any damage arising from such use.
Other prerequisites for appropriate use include:
–observing the instructions, notes and requirements set out in this instruction manual.
–observing all local safety regulations concerning safety at work.
–observing all information and warnings in the documentation dealing with the products used togeth-
er with the transmitter (housings, sensors, etc.).
–observing the prescribed environmental and operational conditions.
- 1 -

1.3 Safety Instructions
- The Alpha pH 2000D should be installed and operated only by personnel familiar with the
transmitter and who are qualified for such work.
- A defective controller must neither be installed nor put into service.
- The Alpha pH 2000D must only be operated under the specified operating conditions (see
section 8).
- The Alpha pH 2000D must not be repaired by the customer.
- The Alpha pH 2000D must only be opened to replace the unit fuse. This work must be
carried out only by personnel familiar with the transmitter and who are qualified for such
work. Make sure the mains cable is separated from the power supply before opening the
unit.
- No modifications to the Alpha pH 2000D are allowed. The manufacturer/supplier accepts no
responsibility for damage caused by unauthorized modifications. The risk is borne
entirely by the user.
1.4 Putting Out of Service / Correct Disposal of the Unit
Putting out of service
•First disconnect the unit from the mains, then undo all electrical connections.
•Remove the unit from the wall / panel.
Correct disposal of the unit
When the transmitter is finally taken out of service, observe the local environmental regulations for
correct disposal or send the transmitter to your local distributor, they will take care of proper disposal.
- 2 -

2 Product Description
2.1 Description of Unit
The Alpha pH 2000D is used for measuring pH and temperature values. The pH values can be measured using industrial
differential & combination pH sensors. The temperature values can be measured using 2-wire / 3-wire NTC300 thermistor.
The transmitter is available in a wall mounting enclosure. The controller / transmitter can be used for applications such as
water treatment and monitoring, galvanic-decontamination, chemical processing, food processing, clean or wastewater
control and neutralization processes.
This transmitter has many user-friendly and safety features which include:
•Push-button for calibration and sensor offset adjustment from the keypad.
•Built-in non-volatile memory to ensure that calibration and other information are not erased if power supply fails.
•Menu-driven program that simplifies set-up.
•Automatic temperature compensation (ATC).
•Manual temperature compensation setting without the ATC probe, with independent setting for calibration and process
temperature.
•Two galvanically isolated current outputs 0/4...20mA.
•Two switching contacts as set-point relays.
•0 to 2000 seconds time delay adjustment on all relays – minimizes false alarms.
•Separately adjustable high and low set-point hysteresis (dead bands) prevent chattering of relays around the set points.
•Three control modes: limit controller, P controller and PI controller (P/PI controller as pulse length or pulse frequency).
•Large dual display LCD for easy reading with clear multiple annunciators, alarm status, operational and error messages.
•Separate alarm relay alerting you to set point limits exceeded for a certain time and if the NTC300 thermistor wires are
broken or disconnected during the ATC function.
•Wash relay.
•Hold function to freeze output current (0/4...20mA) and release control relays.
•LED indicators signal control activities to visually monitor transmitter status from a distance.
•Protection against electromagnetic interference.
•Back lit and UV light protected LC display.
- 3 -

2.2 Measurement and Control System
A typical measurement system consists of:
•A pH/ORP process controller
•A pH/ORP combination electrode with integrated or separate temperature sensor NTC300
thermistor.
•An appropriate pH or ORP measurement cable
•An immersion, flow or process assembly with or without a potential matching pin (PMP)
•A final control element such as pump or valve
•A chart recorder
Power Mains
(80 - 250 VAC)
0/4 - 20 mA
Measurement Cable
Housing and
Sensors
Chart Recorder
Alpha pH 2000D Transmitte
r
- 4 -

2.3 Unit Overview
Wall mounting version
- 5 -

2.3.1 Display Overview
The LC display shows two alpha-numerical fields for parameters and measured values as well as
various mode and status indicators.
MEAS
SETUP
CAL
HOLD
O
C
pH
A
TC
mV
pH %
READY
ERR
O
F
Mode indicators:
MEAS: measurement mode
SETUP: Set-up mode
CAL: Calibration mode
Status indicator:
READY: Visible after successful calibration
HOLD: Unit in “HOLD” mode
ATC: Visible in ATC (Automatic Temperature
Compensation) mode. Not visible in the Manual
Temperature Compensation mode. “ATC” flashes if
the temperature probe is faulty in its ATC mode
ERR: Error indicator
S: Visible in symmetrical measurement mode
2.3.2 Key functions
Key Description
Enter Calibration mode (requires access code)
Enter Set-up mode (requires access code)
Access sub functions (parameters) within a function group of Set-up mode
Confirm (store) set-up parameters and numerical values
Start/Confirm calibration in Calibration mode.
Select function group in the Set-up mode.
Set parameters and numerical values (if key is pressed continuously, the setting speed increases).
Control the relays in MANUAL relay operation.
Returns to “Measurement mode” when both keys are pressed simultaneously.
Display limit values for SP1 and SP2 and settings for wash contact in AUTO relay operation.
Toggle between RELAY A, RELAY B or Wash relay in MANUAL relay operation
Switch from AUTO to MANUAL relay operation (requires access code)
- 6 -

2.3.3 LED indicators
Relay indicators
If REL key is pressed the LED (A, B or W) indicates to which Relay (A, B or Wash)
the displayed limit values refer.
Relay mode indicators
Auto LED lights if relay operation is set to automatic mode. Manu LED lights if relay
operation is set to manual mode.
Relay status indicators
This LED lights if limit value is exceeded or the ATC probe fails.
This LED lights green if measured value is within the limit for Relay A or lights red if
measured value exceeds limit.
This LED lights green if measured value is within the limit for Relay B or lights red if
measured value exceeds limit.
This LED lights if cleaning cycle is on.
2.3.4 Security codes
The access to Calibration mode, Setup mode and Manual relay operation mode is protected with
security codes. The security codes are set at the factory and cannot be changed by the user. The
following security codes are used:
Security code Mode Description
000 View only mode to view actual settings
11 Calibration mode to start calibration
22 Setup mode to configure parameters
22 Manual relay operation to switch relay operation mode from automatic
to manual
- 7 -

2.3.5 Menu overview
CCD “000” = Check calibration parameters (View only mode)
CCD “11” = Calibration mode
SCD “000” = Check setup parameters (View only mode)
SCD “22” = Setup mode
MEAS P
H
°C
SET PU
HOLD
SET PU
HOLD
SET PU
HOLD
SET PU
HOLD
SET PU
HOLD
SET PU
HOLD
SET PU
HOLD
SET PU
HOLD
SET PU
HOLD
Temperature settings
see section 6.3
Relay A (set point 1) settings
see section 6.4
Relay B (set point 2) settings
see section 6.4
Controller settings
see section 6.5
Current output 1 settings
see section 6.6
Current output 2 settings
see section 6.7
Wash contact settings
see section 6.8
Calibration
see section 5
CAL
ENTER
ENT
ENT
ENTER
E
NTER
ENT
ENT
ENT
ENT
ENT
ENT
ENT
ENT
ENT
ENT
SETUP
HOLD
1
2
Unit settings
see section 6.9
ENT
Offset setting
see section 6.2
OFS
- 8 -

3. Assembly and Installation
3.1 Mounting the Unit
Wall mounting version
111.50 [4.39]
144 [5.67]
Unit:
MM [INCH]
approx. 14 [.55]
39 [1.54]
144 [5.67]
78 [3.07]
Pg13.5 (3 pcs.)
27.5 [1.08]
24 [.94]
57.8[2.28]
For P
g
13.5 cable
g
lands
Holes for wall
mounting (2X)
21.5 [.85]
6 [.24]
66.5 [2.62]
80 [3.15]
90 [3.54]
90 [3.54]
Holes for post
mounting (4X)
Red Plugs for wall
mounting holes
enclosure (2X)
175 [6.88]
175 [6.88]
138 [5.43]
138 [5.43]
Cut-out mountin
84 [3.30] 29 [1.14]
1-22 [0.03 - 0.87]
Threaded rod for panel mountin
Max.80
Seal gasket
g
g
plates for post mountin
g
Transmitter housing for wall mounting: protection class IP 65
- 9 -

3.2 Connection Diagram
Caution: Ensure electrical mains are disconnected before proceeding.
Connections for wall mounting version
1
L
2
N
Current
15
Current
13
OP2
14 16
OP1
17
3456
22
HOLD
18 19 2120 23 24 25
78 9 10 11
2926 2827 30 31 32 33
12
-5V
TEMP
SENS TEMP pH
REFpH
MEAS
Fuse: 250V 315 mA,
Time Delay
L
112
24
Current
N
OP2
13
Current
14
2
15 16
OP1
17
3
21
HOLD
18 19 20
4
22 23 28
5
25
6 7
26 27
8
-5V
TEMP
31
TEMP
SENS
29
9
30
10
pH
REF
11
32 33
pH
MEAS
250V, 315 mA,
Time Delay
1. AC mains live wire 18. 12V output Power supply
2. AC mains neutral wire 19. Hold Function
3. AC mains protective earth wire 20. Hold Function
4. Relay A (SP 1) 21. Earth ground
5. Relay A (SP 1) 22. no connection
6. Relay B (SP 2) 23. no connection
7. Relay B (SP 2) 24. no connection
8. Wash relay 25. no connection
9. Wash relay 26. Shield (drain wire)
10. Alarm relay (NC) 27. -5V to differential pH sensor (White wire)
11. Alarm relay common 28. Temperature ground (black wire)
12. Alarm relay (NO) 29. Temperature Sense (Yellow wire)
13. 4-20 mA temperature output, +ve terminal 30. Temperature Input (Yellow wire)
14. 4-20 mA temperature output, -ve terminal (Internally connected by jumper to terminal 29)
15. 4-20 mA pH/ORP output, +ve terminal 31. No connection
16. 4-20 mA pH/ORP output, -ve terminal 32. pH input, Reference (Green wire)
17. 12V output ground 33. pH input, Measure (Red wire)
IMPORTANT: The Alarm relay functions “A s OFF underas an ctive Low” device i.e. it switche
Alarm condition. Therefore the Alarm display device should be connected to the ‘NC’ contacts of
the relay (10 & 11).
h or circuit breaker shall be included in the building installation.
the operator.
NOTE:
a) Switc
b) It shall be in close proximity to the equipment and within easy reach of
c) It shall be marked as the disconnecting device for the equipment.
- 10 -

4 Normal Operation
4.1 Measurement Mode
When the controller/transmitter is powered on, the display first shows all segments briefly, after which
the controller/transmitter automatically enters into the Measurement mode.
Please note: To guarantee accurate readings, the measuring system (transmitter and
sensor) must be calibrated.
pH
MEAS
O
C
The mode indicator “MEAS” at the top of the display indicates that the transmitter is in Measurement
mode. The upper alpha-numerical display shows the measured pH or ORP value, while the lower
display shows the temperature value if the controller is set for pH measurement, or “ORP” if it is set for
ORP measurement.
The annunciators “pH”, “mV” or “%” at the upper right side of the display indicate the current
measurement mode setting whether the controlling is set for pH, mV or ORP % measurement.
From Measurement mode you can access Calibration mode and Setup mode by pressing the CAL
key or ENT key followed by the corresponding security code. For detailed information refer to section
5 “Calibration mode” or section 6 “Setup mode”, respectively.
By pressing the REL key in Measurement mode you can view the actual relay set points. By pressing
the MODE key followed by the corresponding security code in Measurement mode you can switch
relay operation mode from automatic to manual.
For detailed information refer to section 7 “Relay Modes”.
- 11 -

5 Calibration Mode
You can access the Calibration mode directly from the Measurement mode by pressing the CAL key
and entering the Calibration security code “11”. Calibration mode may also be accessed via the Setup
mode (see section 6.1).
5.1 Entering Calibration mode
ENTERENTER
ENTERENTER ENTERENTER
ENTERENTER
MEAS
P
H
O
C
CAL
SETUP
HOLD
SETUP
HOLD
pH calibration
ORP-mV calibration
ORP-% calibration
see section 5.2
see section 5.3
see section 5.4
1. While in Measurement mode press the CAL key (direct access) or ENT key (access via Setup mode).
2. If CAL key was pressed: The display prompts you to enter the calibration security code. Press the ▲or
▼key to set the calibration security code to “11”, and then press the ENT key to confirm the calibration
security code.
3. If ENT key was pressed: The display prompts you to enter the security code. Press the ▲or ▼key to
set the security code to “22”. Press the ENT key to confirm the security code, and then press the ▲or
▼key to select the calibration sub-function.
If configured for pH control, the display shows “CAL PH”. If configured for ORP control, the display
shows “CAL ORP”. To start calibration, refer to the corresponding section (see illustration above).
Note: to exit Calibration mode at any time press the ▲and ▼keys simultaneously
(escape). The transmitter returns to the Measurement mode and the old calibration values
remain active. The calibration security code automatically resets from “11” to “000” after the
transmitter returns to Measurement mode.
Note: The calibration is always carried out in the units (pH or mV or %) selected in setup
mode. The pH controller/transmitter allows a 1-point or 2-point calibration.
- 12 -

5.2 pH Calibration
If the unit of measure is in pH (default), then the calibration is also carried out in pH. This transmitter
features a one-point or two-point calibration for pH with five preset buffer sets. Buffer values refer to 25
oC. A standard pH buffer solution that matches one of these values is required to calibrate the
instrument.
Two point calibration
SETUP
HOLD
P
H
CAL
HOLD
P
H
P
H
CAL
HOLD
P
H
P
H
CAL MEAS
P
H
O
C
atc
CAL
CAL
One point calibration
1. Enter Calibration mode as described in section 5.1. The display shows “CAL PH” (for pH calibration).
Note: If the display reads “CAL ORP”, see section 6.9 for procedures on how to switch from ORP to pH
readings.
2. Press the ENT key to start calibration. The “CAL” indicator appears at the top of display and the buffer
indicator appears in the bottom corner of the display. The display shows the actual pH reading (upper
value) and the buffer value for zero point (lower value). For the offset (zero point) calibration, there are
two values to choose from. They are pH 7.00 or pH 6.86. Using the ▲and▼keys, choose the value
that matches with the buffer used.
3. Place the electrode in the first buffer solution. In ATC mode, you must also immerse the temperature
probe in the buffer solution.
4. You can conduct either a one-point or a two-point calibration: Press the ENT for two point calibration or
the CAL key for one point calibration. The electrode indicator and CAL indicator both flash for a few
seconds. The controller automatically adjusts the reading to match the buffer value.
5. If one-point calibration was selected, the display will show the zero point in the lower section of the
display and the slope (default or using previous two-point calibration) in the upper section of the display.
Proceed to step 7 after zero point display. If two-point calibration was selected, the lower section of the
display will now show its next lower “pH” buffer. Use ▲and ▼keys to select the second buffer from one
of these preset value: - pH 1.68, pH 4.01, pH 9.00, pH 9.18 and pH 10.01. Remove the electrode from
the first buffer, wash and then immerse it into the second buffer. Press the ENT key, the electrode
indicator and CAL indicator will flash for a few seconds. The controller adjusts the reading to the second
buffer.
6. After calibrating the second buffer value, the controller will automatically display the slope in the upper
and the zero point in the lower section of the display.
Note: You can also view the values for zero point and slope without calibration (see section 5.5 for
instruction). The zero point and slope are pre-determined after each calibration.
7. Press the ENT key to return to the Measurement mode.
Note: If you entered the Calibration mode from the Setup mode, the controller will return to the setup menu.
Note: If there is a calibration error, the controller displays “CAL ERR”. If this happens, push
both ▲and ▼keys (escape) to restart the calibration beginning from Step 1.
Note: When calibrating with manual temperature compensation, the controller automatically
changes from the preset process temperature to the calibration temperature. After leaving the
Calibration mode, the controller switches back to process temperature (for setting the
calibration temperature and the process temperature, see Section 6.3)
- 13 -

5.3 ORP-mV Calibration
If controller is configured for ORP-mV measuring you can perform a one-point calibration.
MEAS
CAL
CAL
HOLD
CAL
HOLD
mV
mV R.mV
CAL
250
255
255 255
250
1. Enter Calibration mode as described in section 5.1. The display should read “CAL ORP”.
Note: If the display reads “CAL PH”, see section 6.9 for procedures on how to switch from pH
to ORP-mV readings.
2. Place sensor in the ORP solution.
3. Press the ENT key to start calibration. The “CAL”, buffer and electrode indicator appears on the display.
The upper and lower display shows the current mV output of the electrode without any offset adjustment.
4. Press the ▲or ▼key to adjust the upper display mV value to match your exact reading.
5. Press the ENT key (or CAL key) to confirm. The controller calculates the correction factor and returns to
the Measurement mode. The “R.mV” annunciator (Relative mV) will be shown on the display indicating
that the value displayed is the relative mV value of the default measurement.
5.4 ORP -% Calibration
If controller is configured for ORP-% measuring you can perform a calibration at two points using a low
concentration sample (20%) and a high concentrate sample (80%). To calibrate the controller for ORP
%:
CAL CAL
MEAS
59.0
%%%
CAL
HOLD
CAL CAL
HOLD
C.1 C.2
1. Enter Calibration mode as described in section 5.1. The display should read “CAL ORP”.
Note: If the display reads “CAL PH”, see section 6.9 for procedures on how to switch from pH
to ORP-mV readings.
2. Press the ENT key to start calibration. The display prompts you to place the sensor in the high
concentration sample (relative value of 80%).
3. Place sensor in high concentration sample, then press the ENT key (or CAL key). The electrode and
CAL indicators flash. The unit automatically adjusts its reading to match the solution value.
4. The display prompts you to place the sensor in the low concentration sample (relative value of 20%).
Remove the electrode from the first standard, wash it well and then immerse it in the 20% standard.
5. When the display stabilizes press the ENT key (or CAL key). The electrode and “CAL” indicator flashes
and the controller adjust its display to the 20% relative value and exits to the Measurement mode.
Note: If there is a calibration error, the controller displays “CAL ERR”. If this happens, push
both ▲or ▼keys (escape) to restart the calibration beginning from Step 1.
Note: If you stop calibration after entering the first value, or if calibration is defective, the
controller will use its original calibration data.
- 14 -

5.5 View actual zero and slope
MEAS
PH
O
C
ATC
CAL
ENT
pH
CAL
ENT
1. While in Measurement mode press the CAL key. The display will prompt you to enter a security code.
Leave the security code at “000” (view only mode).
2. Press the ENT key.
The display shows the slope in mV (upper value) and the pH reading at 0 mV (zero point, lower value).
Note: If no key is pressed for 30 seconds the transmitter automatically returns to the
Measurement mode.
3. Press the ENT key to return to the Measurement mode.
- 15 -