Emerson Process Management 3081 pH-ORP User Manual

Model 3081 pH/ORP

Smart Two-Wire Microprocessor Transmitter

Instruction Manual

PN 51-3081pH/rev.D August 2002

ESSENTIAL INSTRUCTIONS

READ THIS PAGE BEFORE PROCEEDING!

Rosemount Analytical designs, manufactures, and tests its products to meet many national and international standards. Because these instruments are sophisticated technical products, you must properly install, use, and maintain them to ensure they continue to operate within their normal specifications. The following instructions must be adhered to and integrated into your safety program when installing, using, and maintaining Rosemount Analytical products. Failure to follow the proper instructions may cause any one of the following situations to occur: Loss of life; personal injury; property damage; damage to this instrument; and warranty invalidation.

• Read all instructions prior to installing, operating, and servicing the product. If this Instruction Manual is not the correct manual, telephone 1-800-6547768 and the requested manual will be provided. Save this Instruction Manual for future reference.

• If you do not understand any of the instructions, contact your Rosemount representative for clarification.

• Follow all warnings, cautions, and instructions marked on and supplied with the product.

• Inform and educate your personnel in the proper installation, operation, and maintenance of the product.

• Install your equipment as specified in the Installation Instructions of the appropriate Instruction Manual and per applicable local and national codes. Connect all products to the proper electrical and pressure sources.

• To ensure proper performance, use qualified personnel to install, operate, update, program, and maintain the product.

• When replacement parts are required, ensure that qualified people use replacement parts specified by Rosemount. Unauthorized parts and procedures can affect the product’s performance and place the safe operation of your process at risk. Look alike substitutions may result in fire, electrical hazards, or improper operation.

• Ensure that all equipment doors are closed and protective covers are in place, except when maintenance is being performed by qualified persons, to prevent electrical shock and personal injury.

CAUTION

If a Model 275 Universal Hart

Communicator is used with these transmitters, the software within the Model 275 may require modification.

If a software modification is required, please contact your local Emerson Process Management Service Group or National Response Center at 1-800-654-7768.

Emerson Process Management Rosemount Analytical Inc.

2400 Barranca Parkway Irvine, CA 92606 USA Tel: (949) 757-8500 Fax: (949) 474-7250

http://www.raihome.com

WHAT YOU NEED TO KNOW

BEFORE INSTALLING AND WIRING A ROSEMOUNT ANALYTICAL

SENSOR TO THE MODEL 3081 pH/ORP TRANSMITTER

1. THE MODEL NUMBER OF THE SENSOR

• Look on the label.

• Also note the model option string.

• If the label is missing or unreadable, see the flowcharts on pages 28 through 30.

Write the sensor model number here

2. THE TYPE OF TEMPERATURE ELEMENT

• Look on the label.

• If the label is missing or unreadable, measure the resistance between the RTD leads.

Write the temperature element RTD here

3. THE LOCATION OF THE PREAMPLIFIER: INSIDE OR OUTSIDE THE TRANSMITTER?

• If the sensor is wired through a junction box, the preamplifier is ALWAYS in the junction box or the sensor.

If resistance is . . . the RTD is . . . about 110 ohms Pt 100 about 3000 ohms Balco 3K

• If the sensor is wired directly to the transmitter, the preamplifier can be in either the sensor or the transmitter.

• Look at the wires in the sensor cable. A GREEN wire means the preamplifier is in the sensor. An coaxial cable means the preamplifier is in the transmitter. A coaxial cable is an insulated wire surrounded by a braided metal shield. The wire terminates in either a BNC connector or an ORANGE wire with a CLEAR shield.

Write the preamplifier location here

CAN YOU USE THE QUICK START GUIDE

ON THE FOLLOWING PAGE?

Use the Quick Start Guide if . . .

1. you are NOT using a HART communicator,

2. you do NOT require an intrinsically safe or explosion-proof installation,

3. you are NOT measuring ORP,

4. you do NOT require transmitter setup beyond programming the 4-20 mA output,

5. you are NOT using a a sensor-mounted junction box or a remote junction box,

6. you are NOT using a sensor made by another manufacturer,

7. you are using one of the following sensors:

Note: Only the model option numbers needed to select the correct wiring diagram in the

Quick Start Guide are shown. Other model option numbers are not shown.

If you cannot use the Quick Start Guide, turn to Section 2.0 of the instruction manual.

Base Model RTD Preamplifier located Model Option (note)

381+ Pt 100 in sensor (green wire) 381+ -55 381+ Pt 100 in transmitter (orange wire) 381+ -52 385+ Pt 100 in sensor (green wire) 385+ -03 385+ Pt 100 in transmitter (orange wire) 385+ -04 396P Pt 100 in transmitter (orange wire) 396P-02-54 396P Pt 100 in sensor (green wire) 396P-01-55 396P Pt 100 in transmitter (orange wire) 396P-02-55 396R Pt 100 in transmitter (orange wire) 396R-54

QUICK START GUIDE FOR MODEL 3081pH/ORP

Before using this Quick Start Guide, please read “WHAT YOU NEED TO KNOW BEFORE INSTALLING AND WIRING A ROSEMOUNT ANALYTICAL SENSOR TO THE MODEL 3081 pH/ORP TRANSMITTER” on the preceding page.

Section 1.1 Setup for the Models 381+-52, 385+-04, 396P-02-54, 396P-02-55 and 396R-54 without a junction box

A. The factory setting of the preamplifier switch is in the appropriate location, so no adjustment is necessary. B. Mount the transmitter in the desired location. Most installations use PN 2002577, pipe mounting bracket. C. Continue the start up with Section 2 Wiring.

Section 1.2 Setup for Sensor Models 381+-55, 385+-03, and 396P-01-55 without a junction box

A. This section shows how to set the preamplifier switch and should be done prior to installation of the transmitter. B. Loosen the cover lock nut on the Model 3081pH/ORP transmitter until the tab disengages from the circuit end cap.

Unscrew and remove the cap. Unscrew the three bolts holding the circuit board stack in the enclosure.

C. Pull up on the display board. Do not disconnect the ribbon cable between it and the CPU board. The CPU and analog

boards are joined by a pin and socket connector along the bottom edge of the boards. Carefully pull the boards apart and remove the CPU board. The analog board is on the bottom and remains in the enclosure. See Figure 1 below.

D. The analog board is shaped like a circle with an arc missing. Directly opposite the straight side is a slide switch. Change

the switch position to the "sensor or j-box" setting by sliding the switch closer to the edge of the board. See Figure 2 below.

E. To reassemble the stack, place the display board on the CPU board. Be sure the display board is properly oriented. The

small square window (the infrared detector for the remote controller) marks the top of the board. Insert the three bolts through the holes. Align the bolts with the standoffs on the analog board and position the display and CPU boards on the analog board. SIf the boards are properly aligned, the bolts will drop in place. Press along the bottom of the stack to seat the pin and socket connector. Tighten the bolts, replace the cap and cover lock nut.

F. Mount the transmitter in the desired location. Most installations use PN 2002577, pipe mounting bracket.

FIGURE 2

FIGURE 1

Section 2 Wiring

A. Wire sensor Model 381+-55, 385+-03, or 396P-01-55 directly to the transmitter as shown in Figure 3. B. Wire sensor Model 381+-52, 385+-04, 396P-02-55, 396P-02-55, or 396R-54 as shown in Figure 4. C. Wire the 12 - 42.4 Vdc power supply to TB-15 (- 4 - 20 mA) and TB-16 (+ 4 - 20 mA).

Section 3 Power up and Calibration

A. Apply dc power to the transmitter. B. Remove the red protective "boot" from the sensor end. Rinse with deionized water and gently pat dry with a tissue (don't

wipe or rub). Place the pH sensor in the first buffer. Install the batteries in the remote controller.

Note: A pH measurement is only as good as the calibration, and the calibration is only as good as the buffers used. A careful buffer calibration is the first step in making an accurate pH measurement. For best results, calibrate with buffers having the same temperature as the process. Allow time for the sensor and buffers to reach the same temperature. If the process temperature is more than 10°°C different from the buffer, allow at least 20 minutes. Be careful using buffers at high temperatures because the pH of many buffers is undefined above 60°C. See the main instruction manual for further information.

C. Aim the infrared remote controller (IRC) at the LCD display.

Press CAL . CALIbrAtE will appear. Press ENTER . CAL bF1 will appear.

D. With the sensor in the first buffer, be sure the glass bulb and the temperature element are completely submerged (i.e. 3

inches). Do not let the weight of the sensor rest on the glass bulb. Swirl the sensor to dislodge trapped bubbles. Press ENTER . bF1 will flash until reading is stable. The measured pH value will appear in the main display. Press Ïor Ðuntil the small number next to bF1 matches the nominal pH buffer value (i.e. 4.01 pH). Press ENTER to save the first calibration point. CAL bF2 will appear.

E. Remove the sensor from the first buffer, rinse, and place in the second buffer.

Press ENTER . bF2 will flash until the reading is stable. The measured pH value will appear in the main display. Press Ïor Ðuntil the small number next to bF2 matches the nominal pH buffer value (i.e. 10.00 pH).

Press ENTER to save the second calibration point. F. Press RESET to return to the process display. The calibration is complete. G. Place the sensor in the process. The start up is complete, although the following optional procedure may be useful.

Section 4 Output (OPTIONAL)

A. This optional procedure assigns specific pH values to the 4 - 20 mA output. The factory default is set to 0.00 pH at 4 mA

and 14.00 pH at 20 mA.

Press PROG . OutPut will appear.

Press ENTER . 4 MA will appear. Use the arrow keys to change the displayed number to the desired pH.

Press ENTER to save. 20 MA will appear. Use the arrow keys to change the displayed number to the desired pH.

Press ENTER to save.

Press RESET to return to the process display.

NOTES:

1. INSTRUMENT JUMPER SUPPLIED BY CUSTOMER.

2. DO NOT CONNECT BLUE WIRE INSIDE TRANSMITTER. INSULATE STRIPPED END OF BLUE WIRE.

FIGURE 3 FIGURE 4

QUICK REFERENCE GUIDE

MODEL 3081PH/ORP

Automatic Buffer Calibration Note: A pH measurement is only as good as the calibration, and the calibration is only as good as the buffers used. For best

results, calibrate with buffers having the same temperature as the process. Allow time for the sensor and buffers to reach the same temperature. If the process temperature is more than 10°C different from the buffer, allow at least 20 minutes. Be careful using buffers at high temperatures. The pH of many buffers is undefined above 60°C. See the main instruction manual for further information.

A. Aim the infrared remote controller (IRC) at the LCD display.

Press HOLD on the IRC. HoLd OFF will appear. Press Ð to toggle the display to HoLd On. Press ENTER to engage hold mode. The HOLD indicator will appear to the left of the pH value.

B. Press CAL . CALIbrAtE will appear.

Press ENTER . CAL bF1 will appear.

C. With the sensor in the first buffer, be sure the glass bulb and the temperature element are completely submerged (about 3

inches deep). Do not let the weight of the sensor rest on the glass bulb. Swirl the sensor to dislodge trapped bubbles. Press ENTER . bF1 will flash until reading is stable. The measured pH value will appear in the main display. Press Ïor Ðuntil the small number next to bF 1 matches the nominal pH buffer value (i.e., 4.01 pH). Press ENTER to save the first calibration point. CAL bF2 will appear.

D. Remove the sensor from the first buffer, rinse and place in the second buffer.

Press ENTER . bF2 will flash until the reading is stable. Press Ïor Ðuntil the small number next to bF 2 matches the nominal pH buffer value (i.e., 10.00 pH). Press ENTER to save the second calibration point.

E. The calibration is complete, but the transmitter remains in the CALIbrAtE sub-menu for two minutes after ENTER is

pressed. Press RESET to return to the process display immediately. F. Place sensor in the process. G. (Optional) For maintenance purposes, track the slope of the pH electrode. The slope value of a new electrode is 59mV

per pH unit, and this value falls over time. The sensor should be changed when the slope nears 47.5mV per pH. To view the slope value, use the following steps.

Press CAL . CALIbrAtE will appear.

Press NEXT . Std will appear.

Press ENTER . The current pH value will appear next to Std.

Press ENTER . SLOPE and the current slope value will appear. Record this number as the slope value.

Press RESET to return to the process display. H. After calibration, press HOLD . HoLd On will display.

Press Ðto toggle the display to HoLd Off. Press ENTER to save this into memory.

The HOLD indicator on the display will turn off.

Standardizing to Match a Reference Instrument Note: Standardization does not perform a true calibration. Regular buffer calibrations are still needed to update the sensor

slope value. For best results take the grab sample from a point as close as possible to the pH sensor and measure the sample at the same temperature as the process.

A. Aim the infrared remote controller (IRC) at the LCD display.

Press HOLD on the IRC. HoLd OFF will appear.

Press Ðto toggle the display to HoLd On.

Press ENTER to engage the hold mode. The HOLD indicator will appear to the left of the pH value. B. Press CAL . CALIbrAtE will appear.

Press NEXT . Std will appear.

Press ENTER . The measured value will appear. C. Take a grab sample of the process and measure it with your reference instrument. Use the editing keys to adjust the value

on the Model 3081pH/ORP to match the reference instrument. Press ENTER to save the corrected pH value. D. If the value is acceptable, the sensor slope is displayed. The slope has not been changed. E. Press RESET to return to the process display. F. After calibration, press HOLD . HoLd On will display.

Press Ðto toggle the display to HoLd Off. Press ENTER to save this into memory.

The HOLD indicator on the display will turn off.

HART Communicator Fast Key Sequences

Technical Support Hotline:

For assistance with technical problems, please call the Customer Support Center (CSC). The CSC is staffed from 5:00am to 5:00pm PST.

Phone (US only): 800-854-8257 Phone: 949-757-8500

Fax: 949-863-9159 World Wide Web: www.raihome.com

PROGRAM

CALIBRATE

OutPut

GIMP 1000 V Er 81PH.21

tEMP 25 C

InPut 58.9 ShoW FLt

nonE

rIMP 10

dIAGnOStIC tEMP

bUFFErdISPLAY ISOPOtntAL

SIM OUtPUt

CALIbrAtE

Std

tEMP AdJ

tEMP 25.0

4 MA 00.00

20MA 14.00

HoLd 21.00 FAULt 22.00

dPn 0.00

tAUtO On

tMAn 25.0

tC 100-3

tYPE PH

tEMP C

OUtPUt Cur

COdE 000

bAUtO On

bUFFEr Std

tIME 10

PH 00.02

tCOEF 00.00

ISO 07.00

Snr 07.00

tESt 12.00

rOFFSt 060

dIAG OFF

IMPtC ON

GWH 1000

GFH 1500

GWL 020

GFL 010

CAL 000

rEF LO

rFH 140

rWH 040

rWL 000

rFL 000

CAL bF1

bF 1

bF1 4.01

CAL bF2

bF 2

bF2 10.01

DIAGNOSE

Std 7.00

SLOPE 59.01

Sub-menu

PROMPT

Diag Message

Menu Tree for pH

Buffer Calibration

2311

Standardize

2321

Trim Analog Output

Toggle Hold Mode

pH Upper Range Value

322

pH Lower Range Value

321

View pH value

111

View Analog Output

View Transmitter Status

MODEL 3081 pH/ORP TABLE OF CONTENTS

MODEL 3081 PH/ORP

MICROPROCESSOR TRANSMITTER

TABLE OF CONTENTS

Section Title Page

1.0 DESCRIPTION AND SPECIFICATIONS ................................................................ 1

1.1 Features................................................................................................................... 1

1.2 Accessories.............................................................................................................. 2

1.3 Specifications - General for Model 3081 pH/ORP.................................................... 3

1.4 Specifications - pH................................................................................................... 4

1.5 Specifications - ORP................................................................................................ 4

1.6 Ordering Information ............................................................................................... 4

2.0 INSTALLATION....................................................................................................... 7

2.1 Unpacking and Inspection........................................................................................ 7

2.2 Pre-Installation Set Up............................................................................................. 7

2.3 Orienting the Display Board..................................................................................... 10

2.4 Mechanical Installation............................................................................................. 10

2.5 Power Supply/Current Loop..................................................................................... 13

3.0 WIRING.................................................................................................................... 14

3.1 General Information................................................................................................. 14

3.2 Wiring Diagrams for pH and ORP Sensors.............................................................. 15

4.0 INTRINSICALLY SAFE AND EXPLOSION PROOF............................................... 31

4.1 Intrinsically Safe Installations................................................................................... 31

4.2 Explosion Proof Installations.................................................................................... 31

5.0 OPERATION WITH REMOTE CONTROLLER ....................................................... 37

5.1 Displays ................................................................................................................... 37

5.2 Infrared Remote Controller (IRC)............................................................................. 38

5.3 Menu Tree - pH........................................................................................................ 39

5.4 Diagnostic Messages - pH....................................................................................... 39

5.5 Menu Tree - ORP..................................................................................................... 40

5.6 Diagnostic Messages - ORP.................................................................................... 40

5.7 Security.................................................................................................................... 41

6.0 OPERATION WITH MODEL 275............................................................................. 42

6.1 Note on Model 275 HART Communicator................................................................ 42

6.2 Connecting the HART Communicator...................................................................... 42

6.3 Operation................................................................................................................. 43

7.0 CALIBRATION OF pH MEASUREMENTS............................................................. 48

7.1 General.................................................................................................................... 48

7.2 Entering and Leaving the Calibrate Menu................................................................ 48

7.3 Using the Hold Function........................................................................................... 48

7.4 Temperature Calibration........................................................................................... 49

7.5 Auto Calibration ....................................................................................................... 50

7.6 Manual Calibration................................................................................................... 52

7.7 Making the Transmitter Reading Match a Second pH Meter (Standardization)....... 54

MODEL 3081 pH/ORP TABLE OF CONTENTS

TABLE OF CONTENTS CONT’D

8.0 PROGRAMMING FOR pH MEASUREMENTS....................................................... 56

8.1 General.................................................................................................................... 56

8.2 Entering and Leaving the Program Menu................................................................ 56

8.3 Output Ranging........................................................................................................ 58

8.4 Diagnostic Parameters............................................................................................. 60

8.5 Temperature Related Settings ................................................................................. 64

8.6 Display Units............................................................................................................ 66

8.7 Buffer Calibration Parameters.................................................................................. 67

8.8 Isopotential Parameters........................................................................................... 69

8.9 Generating a Test Current........................................................................................ 71

9.0 CALIBRATION OF ORP MEASUREMENTS .......................................................... 72

9.1 General.................................................................................................................... 72

9.2 Entering and Leaving the Calibrate Menu................................................................ 72

9.3 Using the Hold Function........................................................................................... 72

9.4 Temperature Calibration........................................................................................... 73

9.5 Standardization........................................................................................................ 74

10.0 PROGRAMMING FOR ORP MEASUREMENTS.................................................... 75

10.1 General.................................................................................................................... 75

10.2 Entering and Leaving the Program Menu................................................................ 75

10.3 Output Ranging........................................................................................................ 77

10.4 Diagnostic Parameters............................................................................................. 79

10.5 Temperature Element............................................................................................... 82

10.6 Display Units............................................................................................................ 83

10.7 Generating a Test Current........................................................................................ 84

11.0 MAINTENANCE ...................................................................................................... 85

11.1 Overview.................................................................................................................. 85

11.2 Transmitter Maintenance ......................................................................................... 85

11.3 pH Sensor Maintenance.......................................................................................... 86

11.4 ORPSensor Maintenance ....................................................................................... 87

11.5 Calibration................................................................................................................ 88

12.0 TROUBLESHOOTING ........................................................................................... 89

12.1 Warning and Fault Messages.................................................................................. 89

12.2 Calibration Errors..................................................................................................... 90

12.3 Troubleshooting - General....................................................................................... 90

12.4 Troubleshooting When a Diagnostic Message is Showing...................................... 90

12.5 Troubleshooting When No Diagnostic Message is Showing.................................... 102

12.6 Systematic Troubleshooting..................................................................................... 107

12.7 Displaying Diagnostic Variables............................................................................... 110

12.8 Testing the Transmitter by Simulating pH................................................................ 110

12.9 Factory Assistance and Repairs .............................................................................. 113

iii

MODEL 3081 pH/ORP TABLE OF CONTENTS

TABLE OF CONTENTS CONT’D

13.0 pH MEASUREMENTS............................................................................................. 114

13.1 General.................................................................................................................... 114

13.2 Measuring Electrode................................................................................................ 115

13.3 Reference Electrode................................................................................................ 115

13.4 Liquid Junction Potential.......................................................................................... 116

13.5 Converting Voltage to pH......................................................................................... 116

13.6 Glass Electrode Slope ............................................................................................. 117

13.7 Buffers and Calibration ............................................................................................ 117

13.8 Isopotential pH......................................................................................................... 118

13.9 Junction Potential Mismatch.................................................................................... 118

13.10 Sensor Diagnostics.................................................................................................. 119

13.11 Shields, Insulation, and Preamplifiers...................................................................... 119

14.0 ORP MEASUREMENTS.......................................................................................... 120

14.1 General.................................................................................................................... 120

14.2 Measuring Electrode................................................................................................ 121

14.3 Reference Electrode................................................................................................ 121

14.4 Liquid Junction Potential.......................................................................................... 121

14.5 Relating Cell Voltage to ORP................................................................................... 122

14.6 ORP, Concentration, and pH.................................................................................... 122

14.7 Interpreting ORP Measurements ............................................................................. 123

14.8 Calibration................................................................................................................ 124

15.0 THEORY - REMOTE COMMUNICATIONS............................................................. 126

15.1 Overview of HART Communications........................................................................ 126

15.2 HART Interface Devices........................................................................................... 126

15.3 AMS Communication............................................................................................... 127

16.0 GLOSSARY............................................................................................................. 128

17.0 RETURN OF MATERIAL......................................................................................... 134

MODEL 3081 pH/ORP TABLE OF CONTENTS

TABLE OF CONTENTS CONT’D

LIST OF FIGURES

Number Title Page

2-1 Model 3081 pH/ORP Transmitter - Exploded Drawing of Circuit Board Stack......... 8

2-2 Model 3081 pH/ORP Transmitter - Analog Board .................................................... 9

2-3 Model 3081 pH/ORP Transmitter - CPU Board........................................................ 10

2-4 Mounting the Model 3081 pH/ORP Transmitter on a Flat Surface........................... 11

2-5 Using the Pipe Mounting Kit to Attach the Model 3081 pH/ORPTransmitter to a Pipe . 12

2-6 Load/Power Supply Requirements .......................................................................... 13

2-7 Power Supply/Current Loop Wiring.......................................................................... 13

3-1 Wiring and Preamplifier Configurations for pH and ORP Sensors........................... 14

3-2 Wire Functions for Models 399-02, 399-09, 381pH-30-41, and 381pHE-31-41.......

before removing BNC and terminating cable ........................................................... 18

3-3 Wire Functions for Models 399-02, 399-09, 381pH-30-41, and 381pHE-31-41.......

after removing BNC and terminating cable. Wire Functions for Models ..................

399-09-10-62, 381pH-30-42, and 381pHE-31-42 as received................................. 18

3-4 Wiring Diagram for Models 399-02, 399-09, 381pH-30-41, and 381pHE-31-41 after

removing BNC and terminating cable. Wiring Diagram for Models ..399-09-10-62,

381pH-30-42, and 381pHE-31-42 as received. Wiring directly to the transmitter.... 18

3-5 Wiring Diagram for Models 399-02, 399-09, 381pH-30-41 after removing BNC and

terminating cable. Wiring Diagram for Model 399-09-10-62, 381pH-30-42, and .....

381pHE-31-42 as received. Wiring through a remote junction box to the transmitter. 18

3-6 Wire Functions for Models 397-50, 397-54, 396-50, 396-54, 396R-50-60, 396R-54-60,

389-02-50, and 389-02-54 before removing BNC and terminating cable................. 19

3-7 Wire Functions for Models 397-50, 397-54, 396-50, 396-54, 396R-50-60, 396R-54-60,

389-02-50, and 389-02-54 after removing BNC and terminating cable. Wire .........

Functions for Models 397-54-62, 396-54-62, and 389-02-54-62 as received.......... 19

3-8 Wiring Diagram for Models 397-50, 397-54, 396-50, 396-54, 389-02-50, and.........

389-02-54 after removing BNC and terminating cable. Wiring Diagram for ............

Models 397-54-62, 396-54-62, and 389-02-54-62 as received. Wiring Directly.......

to the Transmitter ................................................................................................... 19

3-9 Wiring Diagram for Models 397-50, 397-54, 396-50, 396-54, 396R-50-60, 396R-54-60,

389-02-50, and 389-02-54 after removing BNC and terminating cable. Wiring ......

Diagram for Models 397-54-62, 396-54-62, and 389-02-54-62 as received. ..........

Wiring Through a Remote Junction Box to the Transmitter ..................................... 19

3-10 Wire Functions for Models 396R-50, 396R-54, 396R-54-61, 396P-02-50,..............

396P-02-54, 396P-02-55, 385+-04, and 381+-41-52............................................... 20

3-11 Wiring Diagram for Models 396R-50, 396R-54, 396R-54-61, 396P-02-50, 396P-02-54,

396P-02-55, 385+-04, and 381+-41-52. Wiring Directly to the Transmitter ............ 20

3-12 Wiring Diagram for Models 396R-50, 396R-54, 396R-54-61, 396P-02-50, .............

396P-02-54, 396P-02-55, 385+-04, and 381+-41-52. Wiring Through a Sensor-....

Mounted Junction Box to the Transmitter ................................................................ 20

3-13 Wire Functions for Models 396P-01-55, 385+-03, 381+-40-55, and 381+-43-55 .... 21

3-14 Wiring Diagram for Models 396P-01-55, 385+-03, 381+-40-55, and 381+-43-55.... 21

3-15 Wire Functions for Model 385+-02........................................................................... 22

3-16 Wiring Diagram for Model 385+-02 .......................................................................... 22

3-17 Wire Functions for Model 328A-07........................................................................... 23

3-18 Wiring Diagram for Model 328A............................................................................... 23

3-19 Wiring Diagram for Model 320HP-10-55.................................................................. 24

3-20 Wiring Diagram for Model 320HP-10-58.................................................................. 24

3-21 Wire Functions for Model 399-33............................................................................. 25

3-22 Wiring Diagram for Model 399-33 ............................................................................ 25

MODEL 3081 pH/ORP TABLE OF CONTENTS

TABLE OF CONTENTS - CONT’D

LIST OF FIGURES - CONT’D

Number Title Page

3-23 Procedure for Removing BNC Connector and Preparing Coaxial Cable for............

Connection to the Model 3081 pH/ORP Transmitter................................................ 26

3-24 Preparation of Raw Connecting Cable (PN 9200273).............................................. 27

4-1 Intrinsically Safe BASEEFAModel 3081 pH/ORP Label .......................................... 31

4-2 FMRC Installation for Model 3081 pH/ORP Transmitter........................................... 32

4-3 CSAInstallation for Model 3081 pH/ORP Transmitter.............................................. 34

4-4 Explosion-Proof Installation for Model 3081 pH/ORP Transmitter............................ 36

5-1 Process Display Screen........................................................................................... 37

5-2 Program Display Screen .......................................................................................... 37

5-3 Infrared Remote Controller....................................................................................... 38

5-4 Menu Tree for pH..................................................................................................... 39

5-5 Menu Tree for ORP ................................................................................................. 40

6-1 Connecting the HART Communicator ...................................................................... 42

6-2 Menu Tree for pH (HART) ........................................................................................ 44

6-3 Menu Tree for ORP(HART)..................................................................................... 46

8-1 Suggested Glass Impedance Warning and Failure Limits ....................................... 60

8-2 Suggested Warning and Failure Limits for Low Impedance Reference Electrodes. 61

8-3 Suggested Warning and Failure Limits for High Impedance Glass Reference .......

Electrodes ................................................................................................................ 61

10-1 Suggested Warning and Failure Limits for Low Impedance Reference Electrodes. 79

10-2 Suggested Glass Impedance Warning and Failure Limits for a Glass Reference....

Electrode.................................................................................................................. 79

11-1 Exploded View of Model 3081 pH/ORP Transmitter................................................. 85

11-2 Checking the Potential of the Reference Electrode.................................................. 87

12-1 Warning Annunciation............................................................................................... 89

12-2 Fault Annunciation.................................................................................................... 89

12-3 Three-Wire RTD .................................................................................................... 96

12-4 Temperature Simulation into the Model 3081 pH/ORP Transmitter ......................... 97

12-5 Troubleshooting Flow Chart/Preamplifier in Sensor-Mounted Junction Box or........

Remote Junction Box............................................................................................... 108

12-6 Troubleshooting Flow Chart/Preamplifier in Transmitter or Built into Sensor........... 109

12-7 pH Simulation When the Preamplifier is Located in the Transmitter........................ 111

12-8 pH Simulation When the Preamplifier is Located in a Remote Junction Box or.......

in a Sensor-Mounted Junction Box .......................................................................... 111

12-9 Simulate pH Through Model 381+ Sensor Preamplifier........................................... 112

13-1 pH Measurement Cell............................................................................................... 114

13-2 Measuring Electrode (pH) ........................................................................................ 115

13-3 Cross-Section Through the pH Glass....................................................................... 115

13-4 Reference Electrode................................................................................................. 116

13-5 The Origin of Liquid Junction Potential..................................................................... 116

13-6 Glass Electrode Slope.............................................................................................. 117

13-7 Two-Point Buffer Calibration..................................................................................... 118

13-8 Liquid Junction Potential Mismatch.......................................................................... 119

14-1 ORP Measurement Cell ........................................................................................... 120

14-2 Measuring Electrode (ORP)..................................................................................... 121

14-3 Reference Electrode................................................................................................. 121

14-4 The Origin of Liquid Junction Potential..................................................................... 122

14-5 Electrode Potential................................................................................................... 122

14-6 ORP Measurement Interpretation............................................................................. 123

15-1 HART Communications ........................................................................................... 126

15-2 AMS Main Menu Tools ............................................................................................. 127

MODEL 3081 pH/ORP TABLE OF CONTENTS

TABLE OF CONTENTS CONT’D

LIST OF TABLES

Number Title Page

3-1 Wiring Diagrams for Model 399 Sensors.................................................................. 15

3-2 Wiring Diagrams for Model 397 Sensors.................................................................. 15

3-3 Wiring Diagrams for Model 396R Sensors............................................................... 15

3-4 Wiring Diagrams for Model 396P Sensors ............................................................... 16

3-5 Wiring Diagrams for Model 396 Sensors.................................................................. 16

3-6 Wiring Diagrams for Model 389 Sensors.................................................................. 16

3-7 Wiring Diagrams for Model 385+ Sensors................................................................ 17

3-8 Wiring Diagrams for Model 381+ Sensors................................................................ 17

3-9 Wiring Diagrams for Model 381pHE and 381pH Sensors........................................ 17

3-10 Wiring Diagrams for Model 328ASensors ............................................................... 17

3-11 Wiring Diagrams for Model 320HP Sensors............................................................. 17

8-1 pH Settings List ....................................................................................................... 57

8-2 pH Values of Standard Buffer Solutions and the Temperature Range over which ...

pH Values are Defined ............................................................................................. 67

8-3 pH Values of Commercial (technical) Buffers and the Temperature Range over .....

which pH Values are Defined .................................................................................. 68

8-4 Standard and Technical Buffers Recognized by the Model 3081 pH Transmitter .... 68

10-1 ORP Settings List .................................................................................................... 76

11-1 Replacement Parts for Model 3081 pH Transmitter ................................................ 86

12-1 RTD Resistance Values ........................................................................................... 96

MODEL 3081 pH/ORP SECTION 1.0

DESCRIPTION AND SPECIFICATIONS

SECTION 1.0

DESCRIPTION AND SPECIFICATIONS

1.1 Features

1.2 Accessories

1.3 Specifications - General for Model 3081 pH/ORP

1.4 Specifications - pH

1.5 Specifications - ORP

1.6 Ordering Information

• CHANGING FROM pH TO ORP operation takes only seconds.

• REMOTE COMMUNICATION IS SIMPLE; use the hand-held infrared remote controller or any HART® compatible device.

• LARGE TWO LINE DISPLAY shows pH or ORP, temperature, and output signal.

• SIMPLE, INTUITIVE MENUS make programming and calibrating easy.

• AUTOMATIC TWO-POINT BUFFER CALIBRATION reduces errors.

• SOLUTION TEMPERATURE COMPENSATION converts measured pH to the pH at 25°C.

• CONTINUOUS DIAGNOSTICS monitor sensor performance and warn the user of failure (FAULT) or approaching failure (WARNING).

• ROBUST NEMA 4X ENCLOSURE protects the transmitter from harsh plant environments.

• INTRINSICALLY SAFE DESIGN allows the transmitter to be used in hazardous environments (with appropriate safety barriers).

• NON-VOLATILE EEPROM MEMORY retains program settings and calibration data during power failures.

1.1 FEATURES

APPLICATION: The Model 3081pH/ORP Transmitter

with the appropriate pH or ORP sensor measures pH between 0 and 14 and ORP between -1400 and 1400 millivolts. Converting the transmitter from a pH instrument to an ORP instrument takes only seconds.

REMOTE COMMUNICATIONS: Remote communications with the Model 3081 pH/ORP transmitter is easy. The hand-held, push button infrared remote controller works from as far away as six feet. The transmitter also belongs to the Rosemount SMART FAMILY®, so it works with the Model 275 HART® hand-held communicator or with any host that supports the HART protocol.

DISPLAY: The 0.8-inch high LCD main display means pH and ORP values are easy to read even at a distance. Secondary variables, temperature and current output, appear in a 0.3 inch high display.

MENUS: Menu formats for calibration and programming are simple and intuitive. Prompts guide the user through the basic procedures. Diagnostic and error messages appear in plain language. There are no annoying codes to look up.

CALIBRATION: Two-point, temperature-corrected buffer

calibration is standard. To reduce errors caused by impatient operators, the Model 3081 pH/ORP transmitter does not accept calibration data until programmed stability limits have been met. If data are not acceptable, the transmitter displays an error message and does not update the calibration. The transmitter recognizes every buffer scale in common use in the world. Manual twopoint and one-point calibration are also available.

AUTOMATIC TEMPERATURE COMPENSATION:

Temperature compensation is completely automatic. The Model 3081 pH/ORP transmitter is compatible with two, three, and four wire Pt 100, Pt 1000, and 3K Balco RTDs.

SOLUTION TEMPERATURE COMPENSATION: The Model 3081 pH transmitter features solution temperature compensation. The transmitter calculates and displays the pH at 25°C from the pH measured at any temperature. The temperature coefficient of the liquid being measured must be known.

SENSOR DIAGNOSTICS: Continuous diagnostics alert the user to impending or existing sensor failure. Diagnostic messages in plain language aid in troubleshooting. The manual contains a thorough, step-bystep troubleshooting guide.

HOUSING: The Model 3081 pH/ORP transmitter housing meets NEMA 4X standards. The transmitter tolerates outdoor and harsh plant environments. The housing also meets NEMA7B explosion-proof standards.

HAZARDOUS AREA INSTALLATION: Circuits in the Model 3081 pH/ORP transmitter are designed and built to be intrinsically safe when used with the appropriate safety barrier.

OUTPUT: The 4 to 20 mA output signal is fully adjustable between 0 and 14 pH and between -1400 and 1400 mV. During hold and fault conditions the output can be programmed to remain at the last value or go to any value between 3.8 and 22 mA.

1.2 ACCESSORIES

1.2.1 Power Supply. Use the Model 515 Power Supply

to provide the dc loop power required by the Model 3081 pH/ORP transmitter. The Model 515 provides either a single source of power at 48 Vdc and 200 mA or two isolated sources at 24 Vdc and 200 mA each. A junction box (PN 2002188) allows as many as nine 3081 pH/ORP transmitters to be powered from each output. For more information refer to product data sheet 71-515.

1.2.2 Alarm Module. The Model 230A Alarm Module receives the 4-20 mA signal from the Model 3081 pH/ORP transmitter and activates two alarm relays. Specify alarm configuration at the time of ordering. High/high, low/low, and high/low are available. Dead band is adjustable as high as 15% of full scale. For more information, refer to product data sheet 71-230A.

1.2.3 Model 275 HART® COMMUNICATOR. The Model 3081 pH/ORP transmitter is compatible with the Model 275 HART communicator. The HART Communicator allows the user to view pH or ORP, temperature, and current output. The user can also program and configure the transmitter and can download data for transfer to another transmitter or computer. The Model 275 communicator attaches to any wiring terminal across the output loop. A250 ohm load must be between the power supply and the transmitter. Order the Model 275 communicator from Rosemount Measurement. Call (800) 999-9307.

Year 2000 Compliance: Millennium Status

Rosemount Analytical , Uniloc Division, certifies that all instruments designed and manufactured by the Uniloc Division, do not have calendars. No instruments manufactured by Uniloc Division keep track of days, months, or years. This has been validated by reviewing all test and calibration procedures. In calibrating and setting up instruments for shipping, there is no step in any procedure to enter a date.

MODEL 3081 pH/ORP SECTION 1.0

DESCRIPTION AND SPECIFICATIONS

MODEL 3081 pH/ORP SECTION 1.0

DESCRIPTION AND SPECIFICATIONS

minimum voltage and load for HART communication

1.3 SPECIFICATIONS -GENERAL

FOR MODEL 3081 pH/ORP

Case: Cast aluminum containing less than 8% magnesium.

NEMA 4X (IP65), NEMA 7 (explosion-proof) Epoxy-polyester paint, Neoprene O-ring seals

Dimensions: 6.3 in. x 6.9 in. x 6.4 in. (160 mm x 175 mm x

161 mm); diameter 6.1 in (155 mm)

Conduit Openings: 3/4 in. FNPT Reference Impedance: Transmitter accepts high impedance

(i.e. glass) reference electrodes as well as low impedance (i.e. silver-silver chloride) reference electrodes.

Output: Two-wire 4-20 mAoutput with superimposed HART

digital signal. Output can be programmed to go to any value between

3.8 and 22.0 mA to indicate a fault or hold condition.

Response Time: Display reaches 95% of final reading within

10 seconds.

Temperature Sensors: The following RTDs can be used with

the Model 3081 pH/ORP transmitter:

3 and 4 wire Pt 100 RTDs 3 and 4 wire Pt 1000 RTDs 3000 ohm Balco RTD Transmitter can also be used with two-wire RTDs.

Temperature Range: 5°F to 248°F (-15°C to 120°C) Local Display: Two line LCD; first line shows process vari-

able (pH or ORP), second line shows temperature and output signal. When triggered, fault and warning messages alternate with temperature and output readings.

Process variable: 7 segment LCD, 0.8 in. (20 mm) high Temperature/output: 7 segment LCD, 0.3 in. (7 mm) high Display board can be rotated 90 degrees clockwise or

counterclockwise. During calibration and programming, messages and

prompts appear in the temperature/output area.

Power Supply and Load Requirements: See graph below.

A minimum loop resistance of 250 Ω and a minimum power supply voltage of 18 Vdc is required for HART communication. Maximum power supply voltage for intrinsically safe and explosion-proof operation is 42.4 Vdc.

Security: User selected security code prevents

accidental changes to program settings.

Ambient Temperature: -4 to 149°F (-20 to 65°C) Relative Humidity: 0 to 95% (with covers sealed) Storage Temperature: -22 to 176°F (-30 to 80°C) EMI/RFI: Meets the requirements of

EN50081-1 EN50081-2

Hazardous Area Classification:

Explosion Proof:

FM: Class I, Div. 1, Groups B, C & D

Class II, Div. 1, Groups E, F, & G Class III, Div. 1

CSA: Class I, Div. 1, Groups C& D

Class I, Div. 2, Groups A, B, C & D Class II, Div. 2, Groups E, F & G Class III, Div. 1

Intrinsic Safety:

FM: Class I, II & III, Div. 1

T4 T AMB= 40°C; T3AT AMB= 70°C

CSA: Class I, Div. 1

T 3C T AMB=40°C; T3 T AMB=80°C

CENELEC: EEx ia IIC

T5 Tamb=40°C; T4 Tamb=65°C

Non-Incendive:

FM: Class I, Div. 2, Groups A, B, C & D CSA: Class I, Div. 2, Groups A, B, C & D T5

(Tamb=40°C)

Weight/Shipping Weight: 10 lb/10 lb (4.5 kg/4.5 kg).

Weights and shipping weights are rounded to the nearest whole pound.

MODEL 3081 pH/ORP SECTION 1.0

DESCRIPTION AND SPECIFICATIONS

1.6 ORDERING INFORMATION

The Model 3081 pH/ORP Smart two-wire microprocessor transmitter is housed in a NEMA 4X case. Communication with the transmitter is through a hand-held infrared remote controller, a Model 275 HART communicator, or any HART compatible device. Automatic temperature compensation is standard, and the transmitter can be programmed to convert measured pH to pH at 25°C (solution temperature compensation). Continuous sensor diagnostics are standard.

3081pH - 01 - 20 - 67 EXAMPLE

MODEL

3081pH/ORP HART SMART TWO-WIRE MICROPROCESSOR TRANSMITTER

Code REQUIRED SELECTION 01-20 LCD (Infrared Remote Control - included) 01-21 LCD (Infrared Remote Control - not included)

Code AGENCY APPROVALS

67 FM approved, intrinsically safe when used with approved sensor and safety barrier, explosion-proof 69 CSA approved, intrinsically safe when used with approved sensor and safety barrier, explosion-proof 73 CENELEC approved, intrinsically safe, safety barrier required

1.4 SPECIFICATIONS - pH

pH Input Range: 0 to 14 pH Temperature Input Range: 5°F to 248°F (-15°C to 120°C) Output Scale Expansion: Continuously expandable

between pH 0 and 14

Accuracy at 25°C: ±0.01 pH Repeatability at 25°C: ±0.01 pH Resolution: 0.01 pH and 0.1°C or °F Stability at 25°C: 0.25% per year Temperature Compensation: Automatic or manual

between 5°F to 248°F (-15°C to 120°C)

Solution Temperature Compensation: Transmitter will

convert pH measured at any temperature to the pH at 25°C. Temperature coefficient is programmable between -0.044 pH/°C and 0.028 pH/°C

Calibration: Automatic two-point and manual two-point

buffer calibration. For automatic calibration, the transmitter recognizes NIST, DIN 19266 and 19267, JIS 8802, BSM, Merck, and Ingold buffers.

1.5 SPECIFICATIONS - ORP

ORP Input Range: -1400 to 1400 mV Temperature Input Range: 5°F to 248°F (-15°C to 120°C) Output Scale Expansion: Continuously expandable

between -1400 and 1400 mV

Accuracy at 25°C: ±1 mV Repeatability at 25°C: ±1 mV Resolution: 1 mV and 0.1°C or °F Stability at 25°C: 0.25% per year

MODEL 3081 pH/ORP SECTION 1.0

DESCRIPTION AND SPECIFICATIONS

MODEL 3081 pH/ORP TRANSMITTER-SENSOR COMPATIBILITY CHART

PREAMPLIFIER LOCATION

Sensor-mounted Remote

MODEL pH ORP Sensor junction box junction box Transmitter

320B x see note

320HP x see note x

330B x 328A x x x

370 x x x x 371 x x x x

381pH x

381pHE x

381 x

381+ x x x x

385 x x x x

385+ x x x x x x

389 x x x x

396 x x x 396P x x x x x 396R x x x x x

397 x x x

398 x x x x 398R x x x x x

399 x x x x

399-33 x x

GP1 x x x x

NOTE: Preamplifier installed in junction box attached to sensor mounting plate.

MODEL 3081 pH/ORP SECTION 1.0

DESCRIPTION AND SPECIFICATIONS

MODEL/PN DESCRIPTION SHIPPING WEIGHT

515 DC loop power supply, see Section 1.2.1 for details 3 lb/1.0 kg 230A Two alarm module, see Section 1.2.2 for details 3 lb/1.5 kg 275 HART communicator, order from Rosemount Measurement - (800) 999-9307 NA 23572-00 Infrared remote controller, includes two 1.5 V AAAalkaline batteries 1 lb/0.5 kg 23555-00 Remote junction box, includes preamplifier (PN 23557-00), 10 terminals on 2 lb/1.0 kg

sensor side and 12 terminals on transmitter side (additional two terminals

supply power from transmitter to the preamplifier) 23557-00 Preamplifier for remote junction box (PN 23555-00) 1 lb/0.5 kg 23550-00 Remote junction box without preamplifier, 12 terminals on sensor side and 2 lb/1.0 kg

12 terminals on transmitter side 23646-01 Extension cable for connecting transmitter to junction box, 10 conductors with 1 lb per 10 ft

1 internal drain wire, cable is terminated and ready for use, specify length 1.0 kg per 10 m

(in feet) when ordering 9200273 Extension cable for connecting transmitter to junction box, 10 conductors with 1 lb per 10 ft

1 internal drain wire, cable is not terminated, customer must prepare cable 1.0 kg per 10 m

ends, specify length (in feet) when ordering 2002577 Pipe mounting kit for 2-inch pipe, complete, includes mounting bracket, 2 lb/1.0 kg

U bolts, and all necessary fasteners (was model option -07) 9241178-00 Stainless steel tag, specify marking, shipped loose (was model option -11) 1 lb/0.5 kg 9120531 BNC adapter, BNC female to two leads 1 lb/0.5 kg 9210012 Buffer solution, 4.01 pH at 25°C, potassium hydrogen phthalate solution, NIST 2 lb/1.0 kg

pH scale buffer, 16 oz (473 mL) 9210013 Buffer solution, 6.86 pH at 25°C, potassium dihydrogen phosphate and 2 lb/1.0 kg

sodium hydrogen phosphate solution, NIST pH scale buffer, 16 oz (473 mL) 9210014 Buffer solution, 9.18 pH at 25°C, sodium tetraborate solution, NIST pH scale 2 lb/1.0 kg

buffer, 16 oz (473 mL) R508-16OZ ORP standard, 475 ± 20 mV at 25°C, iron (II) ammonium sulfate and iron (III) 2 lb/1.0 kg

ammonium sulfate in 1 M sulfuric acid, 16 oz (473 mL) 5103081P Instruction manual 1 lb/0.5 kg

ACCESSORIES

* Weights rounded up to nearest pound or nearest 0.5 kg.

2.1 UNPACKING AND INSPECTION

Inspect the shipping container. If it is damaged, contact the shipper immediately for instructions. Save the box. If there is no apparent damage, remove the transmitter. Be sure all items shown on the packing list are present. If items are missing, immediately notify Rosemount Analytical.

Save the shipping container and packaging. They can be reused if it is later necessary to return the transmitter to the factory.

2.2 PRE-INSTALLATION SETUP

2.2.1 Transmitter Default Settings

Two jumpers and a switch may need to be changed from the factory default settings before installing the transmitter. The settings tell the transmitter the type of temperature element in the sensor, whether the reference electrode is high or low impedance, and the location of the preamplifier. The factory default settings are given below.

default setting temperature element Pt 100 RTD reference impedance low preamplifier location in transmitter

If your sensor or system is different, the transmitter settings must be changed. If you do not know the type of temperature element in the sensor, whether the reference electrode impedance is high or low, or the location of the preamplifier, refer to Sections 2.2.2, 2.2.3, and 2.2.4.

2.2.2 Temperature Element

The Model 3081 pH/ORP transmitter is compatible with sensors having Pt 100, Pt 1000, or 3K Balco RTDs. pH and ORP sensors manufactured by Rosemount Analytical contain either a Pt 100 or a 3K Balco RTD. Sensors from other manufacturers may have a Pt 1000 RTD. For Rosemount Analytical sensors, the type of temperature element in the sensor is printed on the metalized tag attached to the sensor cable. If the label is missing or unreadable, determine the type of RTD by measuring the resistance across the RTD IN and RTD R TN leads. For the majority of sensors manufactured by Rosemount Analytical, the RTD IN lead is red and the RTD RTN lead is white. For the Model 399-33 ORP sensor, the leads are black and white. The Model 328Asensor has no RTD. The Model 320HP system has a readily identifiable separate temperature element. Resistance at room temperature for common RTDs is given in the table.

If the resistance is... the temperature element is a about 110 ohms Pt 100 RTD about 1100 ohms Pt 1000 RTD about 3000 ohms 3K Balco RTD

2.2.3 Reference Electrode Impedance

The standard silver-silver chloride reference electrode used in most industrial and laboratory pH electrodes is low impedance. EVERY pH and ORP sensor manufactured by Rosemount Analytical has a low impedance reference. Certain specialized applications require a high impedance reference electrode. The transmitter must be programmed to recognize the high impedance reference.

MODEL 3081 pH/ORP SECTION 2.0

INSTALLATION

SECTION 2.0

INSTALLATION

2.1 Unpacking and Inspection

2.2 Pre-Installation Set Up

2.3 Orienting the Display Board

2.4 Mechanical Installation

2.5 Power Supply/Current Loop

MODEL 3081 pH/ORP SECTION 2.0

INSTALLATION

FIGURE 2-1. Model 3081 pH/ORP Transmitter - Exploded Drawing of Circuit Board Stack

2.2.4 Preamplifier Location

pH sensors produce a high impedance voltage signal that must be preamplified before use. The signal can be preamplified before it reaches the transmitter or it can be preamplified in the transmitter. To work properly, the transmitter must know where preamplification occurs. Although ORP sensors produce a low impedance signal, the voltage from an ORP sensor is amplified the same way as a pH signal.

If the sensor is wired to the transmitter through a junction box, the preamplifier is ALWAYS in either the junction box or the sensor. Junction boxes can be attached to the sensor or installed some distance away. If the junction box is not attached to the sensor, it is called a remote junction box. In most junction boxes used with the Model 3081 pH/ORP, a flat, black plastic box attached to the same circuit board as the terminal strips houses the preamplifier. The preamplifier housing in the 381+ sensor is crescent shaped.

If the sensor is wired directly to the transmitter, the preamplifier can be in the sensor or in the transmitter. If the sensor cable has a GREEN wire, the preamplifier is in the sensor. If there is no green wire, the sensor cable will contain a coaxial cable. Acoaxial cable is an insulated wire surrounded by a braided metal shield. Depending on the sensor model, the coaxial cable terminates in either a BNC connector or in a separate ORANGE wire and CLEAR shield.

2.2.5 Changing Switch and Jumper Positions

If the sensor and installation does not match the transmitter default settings in Section 2.2.1, change the settings to the correct values.

1. Refer to Figure 2-1.

2. Loosen the cover lock nut until the tab disengages from the front cover. Unscrew the cover.

3. Remove the three bolts holding the circuit board stack.

4. Lift out the display board. Do not disconnect the ribbon cable between it and the CPU board. The CPU and analog boards are joined by a pin and socket connector along the bottom edge of the boards. Carefully disengage the CPU board from the analog board. The analog board will remain attached to the transmitter body.

5. Set the jumpers and the slide switch on the analog board. Refer to Figure 2-2. a. Temperature element jumper.

Jumper position Temperature element

JP-1 Pt 1000 RTD JP-2 Pt 100 RTD JP-3 3K Balco RTD

b. Reference impedance jumper.

Jumper position Reference impedance

JP-6 low JP-7 high

c. Reference impedance jumper JP-5.

Jumper position Reference impedance

Pin 4 only low

Pin 3 and Pin 4 high

d. Preamplifier location selection switch.

Move slider toward Preamplifier location

edge of board sensor or junction box

center of board transmitter

MODEL 3081 pH/ORP SECTION 2.0

INSTALLATION

FIGURE 2-2. Model 3081 pH/ORP Transmitter Analog Board

DWG. NO. REV.

40308110 H

The transmitter must also be programmed to recognize the RTD. If pH is being measured, see Section 8.5. If ORP is being measured, see Section 10.5.

If sensor diagnostics are to be used with a high impedance reference electrode, the high impedance must be identified in the diagnostics setup program. See Section 8.4 for pH measurements. See Section 10.4 for ORP measurements.

Leave jumper connected on Pin 4 only, unless a high impedance reference is used. (NOTE: all standard sensors use low impedance references).

MODEL 3081 pH/ORP SECTION 2.0

INSTALLATION

6. There are more jumpers on the CPU board. Refer to Figure 2-3. These jumpers are factory set and should NOT need to be moved. This step is for troubleshooting purposes only.

Verify that jumpers JP-1, JP-3, and JP-4 on the CPU board are in the positions shown in Figure 2-3. For installations where 50 Hz ac power is present, closing JP-3 may improve immunity of the transmitter to noise.

7. To reassemble the stack, place the display board on the CPU board. Be sure the display board is properly oriented. The small window (the infrared detector for the remote controller) marks the top of the board. Insert the three bolts through the holes. Align the bolts with the standoffs on the analog board and position the display and CPU boards on the analog board. If the boards are properly aligned, the bolts will drop in place. Press along the bottom of the stack to seat the pin and socket connector. Tighten the bolts.

8. Replace the end cap and lock nut.

2.3 ORIENTING THE DISPLAY BOARD

The display board can be rotated 90 degrees, clockwise or counterclockwise, from the original position. To reposition the display:

1. Loosen the cover lock nut until the tab disengages from the circuit end cap. Unscrew the cap.

2. Remove the three bolts holding the circuit board stack.

3. Lift and rotate the display board 90 degrees, clockwise or counterclockwise, into the desired position.

4. Position the display board on the stand offs. Replace and tighten the bolts.

5. Replace the circuit end cap.

2.4 MECHANICAL INSTALLATION

2.4.1 General information

1. The transmitter tolerates harsh environments. For best results, install the transmitter in an area where temperature extremes, vibrations, and electromagnetic and radio frequency interference are minimized or absent.

2. To prevent unintentional exposure of the transmitter circuitry to the plant environment, keep the security lock in place over the circuit end cap. To remove the circuit end cap, loosen the lock nut until the tab disengages from the end cap, then unscrew the cover.

3. The transmitter has two 3/4-inch conduit openings, one on each side of the housing. Run sensor cable through the left side opening (as viewed from the wiring terminal end of the transmitter) and run power/current loop wiring through the right side opening.

FIGURE 2-3. Model 3081 pH/ORP Transmitter CPU Board

DWG. NO. REV.

40008125 A

MODEL 3081 pH/ORP SECTION 2.0

INSTALLATION

FIGURE 2-4. Mounting the Model 3081 pH/ORP Transmitter on a Flat Surface

MILLIMETER

INCH

4. Use weathertight cable glands to keep moisture out of the transmitter.

5. If conduit is used, plug and seal the connections at the transmitter housing to prevent moisture from getting inside the transmitter.

NOTE

Moisture accumulating in the transmitter housing can affect the performance of the transmitter and may void the warranty.

6. If the transmitter is installed some dist ance from the sensor, a remote junction box with preamplifier in the junction box or in the sensor may be necessary. Consult the sensor instruction manual for maximum cable lengths.

2.4.2 Mounting on a Flat Surface.

See Figure 2-4.

MODEL 3081 pH/ORP SECTION 2.0

INSTALLATION

FIGURE 2-5. Using the Pipe Mounting Kit to Attach the Model 3081 pH/ORP Transmitter to a Pipe

MILLIMETER

INCH

2.4.3 Pipe Mounting.

See Figure 2-5. The pipe mounting kit (PN 2002577) accommodates 1-1/2 to 2 in. pipe.

DWG. NO. REV.

40308104 G

DWG. NO. REV.

40308103 C

MODEL 3081 pH/ORP SECTION 2.0

INSTALLATION

2.5 POWER SUPPLY/CURRENT LOOP

2.5.1 Power Supply and Load Requirements.

Refer to Figure 2-6. The minimum power supply voltage is 12.5 Vdc and

the maximum is 42.4 Vdc. The top line on the graph gives the voltage required to maintain at least 12.5 Vdc at the transmitter terminals when the output signal is 22 mA. The lower line is the supply voltage required to maintain a 30 Vdc terminal voltage when the output signal is 22 mA.

The power supply must provide a surge current during the first 80 milliseconds of start-up. For a 24 Vdc power supply and a 250 ohm load resistor the surge current is 40 mA. For all other supply voltage and resistance combinations the surge current is not expected to exceed 70 mA.

For digital (HART or AMS) communications, the load must be at least 250 ohms. To supply the 12.5 Vdc lift off voltage at the transmitter, the power supply voltage must be at least 18 Vdc.

For intrinsically safe operation the supply voltage should not exceed 42.4 Vdc.

FIGURE 2-6. Load/Power Supply Requirements

FIGURE 2-7. Power Supply/Current Loop Wiring

2.5.2 Power Supply-Current Loop Wiring. Refer to Figure 2-7.

Run the power/signal wiring through the opening nearest terminals 15 and

16. Use shielded cable and ground the shield at the power supply. To ground the transmitter, attach the shield to the grounding screw on the inside of the transmitter case. A third wire can also be used to connect the transmitter case to earth ground.

NOTE

For optimum EMI/RFI immunity, the power supply/output cable should be shielded and enclosed in an earthgrounded metal conduit.

Do not run power supply/signal wiring in the same conduit or cable tray with AC power lines or with relay actuated signal cables. Keep power supply/ signal wiring at least 6 ft (2 m) away from heavy electrical equipment.

An additional 0-1 mA current loop is available between TB-14 and TB-15. A 1 mA current in this loop signifies a sensor fault. See Figure 4-3 for wiring instructions. See Section 8.3 or 10.3 and Section 12.0 for more information about sensor faults.

DWG. NO. REV.

40308122 B

MODEL 3081 pH/ORP SECTION 3.0

WIRING

SECTION 3.0

WIRING

3.1 GENERAL INFORMATION

pH and ORP sensors manufactured by Rosemount Analytical can be wired to the Model 3081 pH/ORPtransmitter in three ways:

1. directly to the transmitter,

2. to a sensor-mounted junction box and then to the transmitter,

3. to a remote junction box and then from the remote junction box to the transmitter.

The pH (or ORP) signal can also be preamplified in one of four places.

1. in the sensor,

2. in a junction box mounted on the sensor,

3. in a remote junction box.

4. at the transmitter.

Figure 3-1 illustrates the various arrangements.

3.1 General Information

3.2 Wiring Diagrams

FIGURE 3-1. Wiring and Preamplifier Configurations for pH and ORP Sensors.

The asterisk identifies the location of the preamplifier. In (a) and (b) the sensor is wired directly to the transmitter. The signal is amplified at the sensor (a) or at the transmitter (b). In (c) the sensor is wired through a sensor-mounted junction box to the transmitter. The preamplifier is in the sensor-mounted junction box. In (d) and (e) the sensor is wired through a remote junction box to the transmitter. The preamplifier is located in the sensor (d) or the junction box (e).

MODEL 3081 pH/ORP SECTION 3.0

WIRING

3.2 WIRING DIAGRAMS FOR pH and ORP SENSORS

Refer to Tables 3-1 through 3-12 to locate the appropriate wire function and wiring diagram. There is a separate table for each model. The sensor models having the highest number appear first. If you do not know the model number of the sensor, refer to the flow charts on pages 28 through 30. Only the model option numbers needed to select the cor-

rect wiring diagram are shown. Other numbers are not shown. For all other sensors, see sensor manual.

Table 3-1. Wiring Diagrams for Model 399 sensors

Sensor Junction Box Preamplifier RTD Wire Function Wiring Diagram

399-02 none in transmitter 3K Balco** Figure 3-2 Figure 3-4

399-02 remote in remote junction box 3K Balco** Figure 3-2 Figure 3-5 399-09* none in transmitter Pt 100 Figure 3-2 Figure 3-4 399-09* remote in remote junction box Pt 100 Figure 3-2 Figure 3-5

399-09-62 none in transmitter Pt 100 Figure 3-3 Figure 3-4 399-09-62 remote in remote junction box Pt 100 Figure 3-3 Figure 3-5

399-33 (ORP only) none in transmitter Pt 100 Figure 3-21 Figure 3-22

Table 3-2 Wiring Diagrams for Model 397 Sensors

Sensor Junction Box Preamplifier RTD Wire Function Wiring Diagram

397-50 none in transmitter 3K Balco** Figure 3-6 Figure 3-8

397-50 remote in remote junction box 3K Balco** Figure 3-6 Figure 3-9 397-54* none in transmitter Pt 100 Figure 3-6 Figure 3-8 397-54* remote in remote junction box Pt 100 Figure 3-6 Figure 3-9

397-54-62 none in transmitter Pt 100 Figure 3-7 Figure 3-8 397-54-62 remote in remote junction box Pt 100 Figure 3-7 Figure 3-9

Table 3-3 Wiring Diagrams for Model 396R Sensors

Sensor Junction Box Preamplifier RTD Wire Function Wiring Diagram

396R-50 remote in remote junction box 3K Balco** Figure 3-10 Figure 3-12 396R-50 none in transmitter 3K Balco** Figure 3-10 Figure 3-11

396R-50-60 sensor-mounted in sensor-mounted junction box 3K Balco** Figure 3-6 Figure 3-9

396R-54 none in transmitter Pt 100 Figure 3-10 Figure 3-11

396R-54 remote in remote junction box Pt 100 Figure 3-10 Figure 3-12 396R-54-60 sensor-mounted in sensor-mounted junction box Pt 100 Figure 3-7 Figure 3-9 396R-54-61 sensor-mounted in sensor-mounted junction box Pt 100 Figure 3-10 Figure 3-12

* Sensors have a BNC connector that the Model 3081 pH/ORP transmitter does not accept. Cut off the BNC and terminate

the coaxial cable as shown in Figure 3-23. Alternatively, use a BNC adapter (PN 9120531).

** Set the RTD jumper to the 3K position (see Section 2.2). Also, program the transmitter to recognize the 3K RTD (see

Section 8.5 for pH or 10.5 for ORP).

MODEL 3081 pH/ORP SECTION 3.0

WIRING

Table 3-4 Wiring Diagrams for Model 396P Sensors

Sensor Junction Box Preamplifier RTD Wire Function Wiring Diagram

396P-01-55 none in sensor Pt 100 Figure 3-13 Figure 3-14 396P-01-55 remote in sensor Pt 100 Figure 3-13 Figure 3-14 396P-02-50 none in transmitter 3K Balco** Figure 3-10 Figure 3-11 396P-02-50 remote in remote junction box 3K Balco** Figure 3-10 Figure 3-12 396P-02-54 none in transmitter Pt 100 Figure 3-10 Figure 3-11 396P-02-54 remote in remote junction box Pt 100 Figure 3-10 Figure 3-12 396P-02-55 none in transmitter Pt 100 Figure 3-10 Figure 3-11 396P-02-55 remote in remote junction box Pt 100 Figure 3-10 Figure 3-12

Table 3-5 Wiring Diagrams for Model 396 Sensor

Sensor Junction Box Preamplifier RTD Wire Function Wiring Diagram

396-50* none in transmitter 3K Balco** Figure 3-6 Figure 3-8 396-50* remote in remote junction box 3K Balco** Figure 3-6 Figure 3-9 396-54* none in transmitter Pt 100 Figure 3-6 Figure 3-8

396-54* remote in remote junction box Pt 100 Figure 3-6 Figure 3-9 396-54-62 none in transmitter Pt 100 Figure 3-7 Figure 3-8 396-54-62 remote in remote junction box Pt 100 Figure 3-7 Figure 3-9

Table 3-6 Wiring Diagrams for Model 389 Sensors

Sensor Junction Box Preamplifier RTD Wire Function Wiring Diagram

389-02-50* none in transmitter 3K Balco** Figure 3-6 Figure 3-8 389-02-50* remote in remote junction box 3K Balco** Figure 3-6 Figure 3-9 389-02-54* none in transmitter Pt 100 Figure 3-6 Figure 3-8

389-02-54* remote in remote junction box Pt 100 Figure 3-6 Figure 3-9 389-02-54-62 none in transmitter Pt 100 Figure 3-7 Figure 3-8 389-02-54-62 remote in remote junction box Pt 100 Figure 3-7 Figure 3-9

* Sensors have a BNC connector that the Model 3081 pH/ORP transmitter does not accept. Cut off the BNC and terminate

the coaxial cable as shown in Figure 3-23. Alternatively, use a BNC adapter (PN 9120531).

** Set the RTD jumper to the 3K position (see Section 2.2). Also, program the transmitter to recognize the 3K RTD (see

Section 8.5 for pH or 10.5 for ORP).

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