Rosemount 389/389VP General Purpose pH/ORP Sensors Manuals & Guides

Page 1
Rosemount™ 389/389VP
General Purpose pH/ORP Sensors
Reference Manual
00809-0100-3389, Rev AA
February 2019
Page 2
Essential Instructions
Emerson 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 Emerson 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 Reference Manual is not the correct one, call 1-800-999-9307 to request the correct Reference Manual. Save this
Reference Manual for future reference.
If you do not understand any of the instructions, contact your Emerson 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 equipment as specified in the installation instructions of the appropriate Reference 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 Emerson.
Unauthorized parts and procedures can affect the product's performance, place the safe operation of your process at risk, and VOID YOUR WARRANTY. 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 people, to prevent electrical shock and personal injury.
WARNING
Hazardous area installation
Installations near flammable liquids or in hazardous area locations must be carefully evaluated by qualified on site safety personnel.
To secure and maintain intrinsically safe installation, use an appropriate transmitter/safety barrier/sensor combination. The installation system must be in accordance with the governing approval agency (FM, CSA, or BASEEFA/CENELEC) hazardous are classification requirements. Consult your transmitter Reference Manual for details.
Proper installation, operation, and servicing of this sensor in a hazardous area installation are entirely the operator's responsibility.
CAUTION
Sensor/process application compatibility
The wetted sensor materials may not be compatible with process composition and operating conditions.
Application compatibility is entirely the operator's responsibility.
CAUTION
Software modifications
If a 275, 375, or 475 Universal HART® Communicator is used with these transmitters, the software within the 275, 375, or 475 may require modification.
If a software modification is required, please contact your local Rosemount Service group or National Response Center at 1-800-654-7768.
2
Page 3
Reference Manual Contents
00809-0100-3389 February 2019

Contents

Chapter 1 Description and Specifications....................................................................................... 5
1.1 Features and applications................................................................................................................. 5
1.2 Specifications................................................................................................................................... 6
1.3 Certifications....................................................................................................................................7
1.4 Ordering information....................................................................................................................... 8
Chapter 2 Install...........................................................................................................................11
2.1 Unpacking and inspection.............................................................................................................. 11
2.2 Mounting....................................................................................................................................... 11
2.3 Electrical installation.......................................................................................................................15
Chapter 3 Calibration................................................................................................................... 27
3.1 Sensor preparation......................................................................................................................... 27
3.2 pH calibration.................................................................................................................................27
3.3 Rosemount™ 389/389VP ORP calibration....................................................................................... 28
Chapter 4 Maintenance................................................................................................................31
4.1 Clean electrode.............................................................................................................................. 31
4.2 Automatic temperature compensator............................................................................................32
4.3 ORP................................................................................................................................................ 33
Chapter 5 Troubleshooting.......................................................................................................... 35
Chapter 6 Return of Material........................................................................................................37
Appendix A EC Declaration of Conformity....................................................................................... 39
Appendix B China RoHS Table......................................................................................................... 43
Appendix C Intrinsically Safe Sensor Installation Drawing - FM........................................................ 45
Reference Manual 3
Page 4
Contents Reference Manual
February 2019 00809-0100-3389
4 Rosemount 389/389VP
Page 5
Reference Manual Description and Specifications
00809-0100-3389 February 2019

1 Description and Specifications

1.1 Features and applications

Rosemount 389VP triple-junction sensors are offered with SMART capabilities. SMART options are enabled when used with Rosemount 1056, 1057, 1066, and 56 transmitters. The pH-loop capabilities include auto-recognition of the SMART sensor, automatic upload of calibration data and associated time stamp, and historical recording of pH diagnostics (slope, offset, reference impedance, and glass impedance). This trending data allows technicians to predict frequency of maintenance and estimate sensor life for a particular process condition. Additional SMART features include factory calibration, resetting SMART sensor calibration data with user menus without power cycling, and manufacturing information.
The reference junction aids in the sensor's resistance to poisoning ions and helps prolong sensor life. Rosemount 389/389VP sensors have a triple junction reference, which protects the reference element from poisoning ions - such as ammonia, chlorine, cyanides, and sulfides - in the process. Both models are made with anouter ceramic junction constructed in an annualr design around the pH/ORP sensitive membrane.
The AccuGLASS™ pH glass formulations exceed industry standards. The AccuGlass pH glass is a result of many years of glass research resulting in a formulation which has been found to increase the life of the sensor. Unlike other pH glasses presently on the market, this glass resists cracking, especially at higher temperatures, and reduces sodium ion errors commonly found in high pH applications. Overall, the AccuGlass formulation enhances the sensor performance to measure pH more accurately and have a longer sensor life than ever before.
A choice of pH glass electrodes is available to best meet various application needs. Two types are available: general purpose and high pH glass. The AccuGlass hemi bulb is the standard glass offered on both types and can be used for most applications.
The Rosemount 389VP is configured with a Variopol (VP8) sensor-to-cable connector
which eliminates re-wiring and cable twisting when replacing sensors. The Variopol VP8 multiple pin connector option uses a mating VP cable. Once the cable is installed and wired to the transmitter, sensors are easily replaced without replacing the cable and without rewiring the transmitter. Also, the cable can be disconnected from the sensor before removal from the process which eliminates cable twisting. VP8 cable assemblies work with both VP8 and VP6 sensor connectors.
The Rosemount 389/389VP has a molded Tefzel body with Viton O-rings, making each sensor very robust and chemically resistant. Complete encapsulation eliminates leakage or high humidity problems traditionally found in other pH/ORP designs. The seimplified construction, designed with user convenience in mind, does not require electrolyte (KCl) replenishment or any high maintenance troubleshooting procedures.
Rosemount 389/389VP sensors are combintation sensors (pH, reference, and temperature within sensor body) and measure pH or ORP (oxidation/reduction potential) of aqueous solutions in pipelines, open tanks, or ponds. rosemount 389/389VP sensors are suitable for virtually all applications and are compatible with Rosemount and other manufacturers' instruments.
Reference Manual 5
Page 6
Description and Specifications Reference Manual
February 2019 00809-0100-3389
Installation is easily achieved through the wide variety of mounting configurations.
These sensors feature a 1 inch (MNPT) front and rear facing connections for insertion, submersion, or flow-through pH and ORP applications.

1.2 Specifications

Table 1-1: Percent linearity over pH range
pH range GPLR glass (-10) High pH glass (-11)
0 to 2 pH 94% 94%
2 to 12 pH 99% 97%
12 to 13 pH 97% 98%
13 to 14 pH 92% 98%
Table 1-2: Rosemount 389/389VP pH/ORP sensor specifications
Measurement range
pH 0 to 14
ORP -1500 to +1500 mV
Temperature range
32 to 185 °F (0 to 85 °C)
Automatic temperature compensation : 32 to 185 °F (0 to 85 °C)
Maximum pressure
100 psig (790 kPa[abs]) at 150 °F (65 °C) - see Figure 1-1
Materials of construction
Sensor body Tefzel
pH electrode Glass
ORP electrode Platinum
Junction Ceramic
O-ring Viton
Process connections
Front facing 1 in. MNPT
Rear facing 1 in. MNPT
Cable
389 Integral preamplifier - 25 ft (7.8 m); no preamplifier - 15 ft
(4.6 m)
389VP Use 24281-XX, 2.5 ft (0.8 m) to 100 ft (31 m) (see
Accessories)
Weight/shipping weight
1 lb / 2 lb (0.45 kg / 0.9 kg)
6 Rosemount 389/389VP
Page 7
Reference Manual Description and Specifications
00809-0100-3389 February 2019
Figure 1-1: Pressure/temperature operating range for Rosemount 389/389VP

1.3 Certifications

IECEx
Sensors without preamp (pH and ORP): Ex ia IIC T4 Ga (-20 ºC ≤ Ta ≤ +60 ºC)
Sensors with SMART preamp (pH only): Ex ia IIC T4 Ga (-20 ºC ≤ Ta ≤ +60 ºC)
Sensors with standard preamp (ORP only): Ex ia IIC T4 Ga (-20 ºC ≤ Ta ≤ +80 ºC) or Ex IIC T5 Ga (-20 ºC ≤ Ta ≤ +40 ºC)
Per standards IEC60079-0: 2011, IEC 60079-11: 2011
ATEX
Sensors without preamp (pH and ORP): II 1 G Ex ia IIC T4 Ga (-20 ºC ≤ Ta ≤ +60 ºC)
Sensors with SMART preamp (pH only): II 1 G Ex ia IIC T4 Ga (-20 ºC ≤ Ta ≤ +60 ºC)
Sensors with standard preamp (ORP only) - II 1 G Ex ia IIC T4 Ga (-20 ºC ≤ Ta ≤ +80 ºC) or II 1 G Ex ia IIC T5 Ga (-20 ºC ≤ Ta ≤ +40 ºC)
Per standards EN 60079-0:2012 + A11:2013, EN 60079-11:2012
FM
See online FM Certificate of Compliance for applicable sensor options:
Intrinsically safe for use in Class I, II, and III, Division 1, Groups A, B, C, D, E, F, and G; Temperature Class T6 Ta = -20 °C to + 60 °C
Intrinsically safe for use in Class I, Zone 0, AEx ia IIC T6 Ta = -20 °C to + 60 °C
Nonincendive for use in Class I, Division 2, Groups A, B, C, and D; Temperature Class T6 Ta = -20 °C to + 60 °C
Reference Manual 7
Page 8
Description and Specifications Reference Manual
February 2019 00809-0100-3389
Suitable for use in Class II and III, Division 2, Groups E, F, and G; Temperature Class Ta = -20 °C to + 60 °C Hazardous (Classified) Locations
IS/I, II, III/1/ABCDEFG/T6 Ta = 60 °C - 140332; Entity: I/0/AEx ia IIC/T6 Ta = 60 °C - 1400332; Entity; NI/I/2/ABCD/T6 Ta = 60 °C; S/I, III/2/EFG/T6 Ta = 60 °C; Entity Parameters
Per standards 3600: 1998; 3610: 2010, 3611:2004, 3810:2005
CSA
See online CSA Certificate of Compliance for applicable sensor options:
Intrinsically Safe: Class I, Division 1, Groups ABCD; Class II, Division 1, Groups EFG; Class III, Class I, Division II, Groups ABCD; Ambient temperature rating -20 °C to + 60 °C; Ex ia IIC; T6
Intrinsically Safe and Non-Incendive: Class I, Division 1, Groups ABCD; Class II, Division 1, Groups EFG; Class III; Class 1, Division 2, Groups ABCD; Ex ia IIC; T6; Ambient temperature rating -20 °C to + 60 °C: (Simple Apparatus)
Class I, Division 1, Groups ABCD; Class II, Division 1, Groups EFG; Class III; Class I, Division 2, Groups ABCD; Ex ia IIC; T6; Ambient temperature rating -20 °C to + 60 °C: (Simple Apparatus)
Per standards C22.2 No. 144 -M1987, C22.2 No 157 - M1992, CAN/CSA E60079:0:07, CAN/CSA E60079:11:02, UL 50, UL 508, UL 913, UL 60079-0:2005, UL 60079-11: 2002

1.4 Ordering information

The Rosemount 389 and 389VP General Purpose pH/ORP Sensors are housed in a molded Tefzel body with 1 in. MNPT forward and rear facing threads suitable for insertion, submersion, or flow through installation. The sensors can be configured with a general purpose pH, high pH, or platinum ORP electrode. Rosemount 389VP sensors are offered with SMART preamplifiers for pH measurements and standard integral preamplifiers for ORP measurements. These sensors may be configured without a preamplifier, but must be used with a remote preamplifier (j-box or transmitter). Automatic temperature compensation is standard. Sensors are available with either an integral cable connection (389) or Variopol (VP6) connector (389VP). Variopol cables sold separately (see Table 5-2).
Table 1-3: Rosemount 389 pH/ORP Sensor ordering information
Model Sensor type
389 pH/ORP Sensor
Preamplifier/cable
01 Integral pramplifier, 25 ft cable
02 No preamplifier, 15 ft cable
(1)
Combination electrode
10 pH -GPLR glass
11 pH-high pH glass
12 ORP
8 Rosemount 389/389VP
Page 9
Reference Manual Description and Specifications
00809-0100-3389 February 2019
Table 1-3: Rosemount 389 pH/ORP Sensor ordering information (continued)
Transmitter/TC compatibility
50 1181, 1050, 1060 (code -01 or -02)
54 1054A/B, 81, 2081, (code -01 or -02); for 54, 56, 1055, 1056, 1057, 1066, 5081, 6081, and XMT (code
-02 only)
55 54, 56, 1055, 1056, 1057, 5081, 6081, and XMT (code -01 only)
Optional
- No selection
62 Cable without BNC for models: 54, 56, 1055, 1056, 1057, 1066, 5081, 6081, and XMT (codes -02 and
-54 only)
Typical model number: 389-02-10-54-62
(1) Preamplifier is SMART if selected with pH electrode and option 55 only. Preamplifier is standard for ORP electrodes and
for options 50 and 54.
Table 1-4: Rosemount 389VP pH/ORP Sensor ordering information
Model Sensor type
389VP pH/ORP sensor
Combination electrode
10 pH - GPLR glass
11 pH - high pH glass
12 ORP
Transmitter/TC compatiblity
50 1181, 1050, 1060 (code -01 or -02)
54 1054A/B, 81, 2081 (code -01 or -02); for 54, 56, 1055, 1056, 1057, 1066, 5081, 6081, and
XMT (code -02 only)
55 54, 56, 1055, 1056, 1057, 5081, 6081, and XMT (code -01 only)
Preamplifier option
- No preamplifier
70 SMART preamplifier
Typical model number: 389VP-10-55-70
(1) Only available with -10, -11, and -55 options.
(1)
Reference Manual 9
Page 10
Description and Specifications Reference Manual
February 2019 00809-0100-3389
10 Rosemount 389/389VP
Page 11
Reference Manual Install
00809-0100-3389 February 2019

2 Install

2.1 Unpacking and inspection

Procedure
1. Inspect the outside of the carton for any damage.
2. If damage is detected, contact the carrier immediately.
3. Inspect the hardware.
4. Make sure all the items in the packing list are present and in good condition.
5. Notify the factory if any part is missing.

2.2 Mounting

The sensor has been designed to be located in industrial process environments. Temperature and pressure limitations must not be exceeded at any time. A label regarding this matter is attached to the sensor with the cable and should not be removed.
Figure 2-1: Rosemount 389 Sensor Dimensional Drawing
A. pH/ORP electrode B. TC C. 1-in. MNPT
D. 1-in. wrench opening
E. 1-in. MNPT
Reference Manual 11
Page 12
Install
February 2019 00809-0100-3389
Figure 2-2: Rosemount 389VP Sensor Dimensional Drawing
Reference Manual
A. VP (Variopol Connection) B. 1-in. wrench opening C. 1-in. MNPT x 2
D. T.C.
E. pH/ORP electrode
WARNING
IRRITANT Internal electrolyte fill may cause skin or eye irritation.
Mounting guidelines
1. Shake down the sensor to remove any air bubbles that may be present inside the tip of the pH glass.
2. Do not install the sensor horizontally. The sensor must be 10° off the horizontal to ensure accuracy.
3. Do not install the sensor upside down.
4. With the standard recessed electrode, air bubbles may become trapped in the sensor end. This problem is most commonly encountered in areas of low flow or during calibration. Shake the probe while it is immersed in solution to remove bubbles.
12 Rosemount 389/389VP
Page 13
Reference Manual Install
00809-0100-3389 February 2019
In most cases, the sensor can simply be installed as shipped, and you can obtain readings with an accuracy of ±0.2 pH. To obtain greater accuracy or to verify proper operation, the sensor must be calibrated as a loop with its compatible analyzer or transmitter.

2.2.1 Submersion mounting

Rosemount 389 and 389VP Sensors have a 1-in. MNPT process connection at the back of the sensor.
Procedure
1. To prevent rain water or condensation from running into the sensor, use a weatherproof junction box (see Figure 2-3).
2. Using a standard 1-in. union, mount the sensor to a 1-in. SCH 80 CPVC or PVDF standpipe.
3. Tapered pipe threads in plastic tend to loosen after installation. We therefore recommend that you use PTFE tape on the threads and check the tightness of the connection frequently to ensure that no loosening has occurred.
Reference Manual 13
Page 14
Install
February 2019 00809-0100-3389
Figure 2-3: Submersion Installations
Reference Manual
4. Run the sensor cable through a protective conduit for isolation from electrical interference or physical abuse from the process.
5. Install the sensor within 80° of vertical, with the electrode facing down. Do not run the sensor's cable with power or control wiring.
2.2.2
14 Rosemount 389/389VP

Flow through and insertion mounting

Rosemount 389 and 389VP sensors also have a 1-in. MNPT process at the front of the sensor for mounting into a 1¼-in. tee or the process. See Figure 2-4 for installation configurations.
Page 15
Reference Manual
00809-0100-3389 February 2019
Figure 2-4: Flow Through and Insertion Installations
A. Angle flow B. Straight flow C. Pipe "Y"
D. 1½-in. x 1-in. reducing bushing
E. 1½-in. pipe tee F. 1½-in. pipe "Y"
G. flow
Install
Note
Valves and fittings by others. Mount the sensor at least 10° from horizontal.
Note
Do not use large pipe wrenches to tighten the sensor into a flange or other type of mounting.

2.3 Electrical installation

Figure 2-5 through Figure 2-19 provide the guidelines for wiring Rosemount 389/389VP
sensors to various Rosemount transmitters.
1. If the cable needs to be extended, use a high quality four-conductor shielded instrument cable available from Rosemount.
Note
If the cable is too long, loop up the excess cable. If the cable has to be shortened, splice and terminate each conductor and make sure that the overall (outermost) drain wire is not shorted out with either of the two inner drain wires (shields).
2. Signal cable should be run in a dedicated conduit (preferably an earth grounded metallic conduit) and should be kept away from AC power lines. A spade lug kit is provided in a plastic bag wrapped around the cable.
Reference Manual 15
Page 16
Install Reference Manual
February 2019 00809-0100-3389
Figure 2-5: Rosemount 389 with Insertion Mounting Adapter P/N 23242-02
A. Cable B. ¾-in. FNPT C. Peek adapter; 1-in. PNPT x ¾-in. FNPT (reversible)
D. 2-135 Viton "O" ring
Note
"O" ring must be inplace prior to use (PN 9550175)
E. Nut, hex union 2-in.; 3-in. wrench opening (304 SST)
F. 2.531.8 ACME thread (TYP) G. Neck, union fitting (316 SST); 2 5/8-in. wrench opening H. 1½-in. MNPT
Figure 2-6: VP 8 Cable, Rosemount 389VP Sensor End
16 Rosemount 389/389VP
Page 17
Reference Manual Install
00809-0100-3389 February 2019
Figure 2-7: VP8 Cable, Instrument End
A. Earth ground B. ID
Note
For additional wiring information on this product, including sensor combinations not shown here, refer to the Liquid Transmitter Wiring Diagrams.
C. Solution ground
D. Note
For additional wiring information on this product, including sensor combinations not shown here, refer to the Liquid Transmitter Wiring Diagrams.
E. Ref in
F. pH/mV IN G. pH/mV SHIELD H. RTD return
I. RTF sense J. RTD IN
Reference Manual 17
Page 18
Install Reference Manual
February 2019 00809-0100-3389
Figure 2-8: Rosemount 389-01-xx-55 Wiring to Rosemount 1056, 1057, and 56 Transmitters
18 Rosemount 389/389VP
Page 19
Reference Manual Install
00809-0100-3389 February 2019
Figure 2-9: Rosemount 389-01-xx-55 Wiring to Rosemount 1066 Transmitter
Figure 2-10: Rosemount 389-01-xx-55 Wiring to Rosemount 5091 Transmitter
Reference Manual 19
Page 20
Install Reference Manual
February 2019 00809-0100-3389
Figure 2-11: Rosemount 389VP Wiring to Rosemount 1056, 1057, and 56 Transmitters
20 Rosemount 389/389VP
Page 21
Reference Manual Install
00809-0100-3389 February 2019
Figure 2-12: Rosemount 389VP Wiring to Rosemount 1066 Transmitter
Figure 2-13: Rosemount 389VP Wiring to Rosemount 5081 Transmitter
Reference Manual 21
Page 22
Install Reference Manual
February 2019 00809-0100-3389
Figure 2-14: Rosemount 389VP-xx-55-70 Wiring to Rosemount 1056, 1057, and 56 Transmitters
Figure 2-15: Rosemount 389VP-xx-55-70 Wiring to Rosemount 1066 Transmitter
22 Rosemount 389/389VP
Page 23
Reference Manual Install
00809-0100-3389 February 2019
Figure 2-16: Rosemount 389VP-xx-55-70 Wiring to Rosemount 5081 Transmitter
Reference Manual 23
Page 24
Install Reference Manual
February 2019 00809-0100-3389
Figure 2-17: Rosemount 389-02-xx-54-62 Wiring to Rosemount 1056, 56, and 1057 Transmitters
24 Rosemount 389/389VP
Page 25
Reference Manual Install
00809-0100-3389 February 2019
Figure 2-18: Rosemount 389-02-xx-54-62 Wiring to Rosemount 1066 Transmitter
Figure 2-19: Rosemount 389-02-xx-54-62 Wiring to Rosemount 5081 Transmitter
Reference Manual 25
Page 26
Install Reference Manual
February 2019 00809-0100-3389
26 Rosemount 389/389VP
Page 27
Reference Manual
00809-0100-3389 February 2019
Calibration

3 Calibration

3.1 Sensor preparation

Procedure
1. Shake down the sensor to remove any air bubbles that may be present at the tip of the pH glass bulb.
2. In most cases, the pH sensor can simply be installed as shipped, and readings may be obtained with an accuracy of ±0.2 pH. To obtain greater accuracy or to verify proper operation, calibrate the sensor as a loop with its compatible transmitter.

3.2 pH calibration

1. After a temporary connection is established between the sensor and the instrument, a buffer calibration may be performed.
3.2.1
2. Consult the appropriate pH/ORP transmitter instruction manual for specific calibration and standardization procedures, or see below for the recommended two-point buffer calibration procedure.

Recommended two point buffer calibration procedure

Prerequisites
Select two stable buffer solutions, preferably pH 4.0 and 7.0. (pH buffers other than pH 4.0 and pH 7.0 can be used as long as the pH values are at least two pH units apart).
Note
A pH 7 buffer solution reads an mV value of approximately zero, and pH buffers read approximately ±59.1 mV for each pH unit above or below pH 7. Check the pH buffer manufacturer specifications for millivolt values at various temperatures, as it may affect the actual value of the buffer solution mV/pH value.
Procedure
1. Immerse the sensor in the first buffer solution. Allow the sensor to adjust to the buffer temperature (to avoid errors due to temperature differences between the buffer solution and sensor temperature) and wait for readings to stabilize.
The value of the buffer can now be acknowledged by the transmitter.
2. Once the first buffer has been acknowledged by the transmitter, rinse the buffer solution off the sensor with distilled or deionized water.
3. Repeat steps 1 and 2 using the second buffer solution. Once the transmitter has acknowledged both buffer solutions, a sensor slope
(mV/pH) is established (the slope value can be found within the transmitter). The slope value should read about 59.1 mV/pH for a new sensor and will decrease over
Reference Manual 27
Page 28
Calibration
February 2019 00809-0100-3389
time to approximately 47 -49 mV/pH. Once the slope reads below the 47-49 mV/pH range, install a new sensor to maintain accurate readings.
Reference Manual

3.2.2 Recommended pH sensor standardization

For maximum accuracy, the sensor can be standardized in-line or with a process grab sample after a buffer calibration has been performed and the sensor has been conditioned to the process. Standardization accounts for the sensor junction potential and other interferences. Standardization does not change the sensor's slope, but simply adjusts transmitter's reading to match that of a known process pH.
Procedure
1. While obtaining a process solution sample (we recommend that you take the sample close to the sensor), record the pH value that is shown on the transmitter display.
2. Measure and record the pH of the process solution sample with another temperature compensated, calibrated pH instrument. For best results, perform standardization at the process temperature.
3. Adjust the transmitter to the standardized value.

3.3 Rosemount™ 389/389VP ORP calibration

Most industrial applications have a number of ORP reactions occuring in sequence or simultaneously. There can be several components that are oxidized or reduced by the reagents that are used. Theoretically, the ORP potential is absolute, because it is the result of the oxidation/reduction equilibrium. However, the actual measured potential is dependent on many factors, including the condition of the surface of the ORP platinum electrode. Therefore the sensor should be allowed 1-2 hours to become conditioned to the stream when first set up or after being cleaned.
WARNING
CORROSIVE SUBSTANCE The solution used during the following check is an acid and should be handled with care. Follow the directions of the acid manufacturer. Wear the proper protective equipment. Do not let the solution come in contact with skin or clothing. If contact with skin is made, immediately rinse with clean water.
Procedure
1. Make a temporary electrical connection between the sensor and the instrument.
2. Obtain a standard solution of saturated quinhydrone (PN R508-16OZ). To make this solution, add a few crystals of quinhydrone to either pH 4 or pH 7 buffer.
Quinhydrone is only slightly soluble, but only a few crystals are required.
3. Immerse the sensor in the standard solution. Allow one to two minutes for the ORP sensor to stabilize.
4. Adjust the standardized control of the transmitter to the solution value shown in
Table 3-1.
28 Rosemount 389/389VP
Page 29
Reference Manual Calibration
00809-0100-3389 February 2019
The resulting potentials, measured with a clean platinum electrode and saturated KCl/AgCL reference electrode, should be within ±20 millivolts of the value shown in
Table 3-1. Note solution temperature to ensure accurate interpretation of results.
The ORP value of saturated quinhydrone solution is not stable over long periods of time. Therefore, make these standards fresh each time they are used.
Table 3-1: ORP of Saturated Quinhydrone Solution (Millivolts)
pH 4 solution pH 7 solution
Temp ºC 20 25 30 20 25 30
mV potential
268 264 260 94 87 80
5. Remove the sensor from the buffer, rinse, and install in the process.
Reference Manual 29
Page 30
Calibration Reference Manual
February 2019 00809-0100-3389
30 Rosemount 389/389VP
Page 31
Reference Manual
00809-0100-3389 February 2019
Maintenance

4 Maintenance

Rosemount™ 389/389VP sensors require minimum maintenance. Keep the sensors clean and free of debris and sediment at all times. The frequency of cleaning by wiping or brushing with a soft cloth or brush is determined by the nature of the solution being measured. Remove sensors from the process periodically and check them in buffer solutions.
WARNING
PRESSURE AND TEMPERATURE Before removing the sensor, be absolutely certain that the process pressure is reduced to 0 psig and the process temperature is lowered to a safe level!
If the sensor will not calibrate, refer to your transmitter reference manual for proper test procedures. If you determine that the sensor has failed, discard and replace it.

4.1 Clean electrode

If the electrode is coated or dirty, clean as follows:
Procedure
1. Remove the sensor from process.
2. Remove the sensor from process as instructed in Retractable version
3. Wipe the glass bulb with a soft, clean, lint free cloth or tissue. If this does not remove the dirt or coating, go to Step 4 (detergents clean oil and grease; acids remove scale.)
4. Wash the glass bulb in a strong detergent solution and rinse it in clean water. If this does not clean the glass bulb, go to Step 5.
WARNING
CORROSIVE SUBSTANCE The solution used during the following step is an acid; handle with care. Follow the directions of the acid manufacturer. Wear the proper protective equipment. Do not let the solution come in contact with skin or clothing. If contact with skin is made, immediately rinse with clean water.
5. Wash the bulb in a dilute 5% hydrochloric acid solution and rinse with clean water. Soaking the sensor overnight in the acid solution can improve cleaning action.
Replace the sensor if it cannot be cleaned.
6. Following the Warning above, wash the glass bult in dilute 5% hydrochloric acid solution and then rinse it thoroughly with clean tap water. Replace the sensor if it cannot be clean. If the glass bulb appears clean, proceed to Step 7.
7. Buffer calibrate the sensor.
Reference Manual 31
Page 32
Maintenance Reference Manual
February 2019 00809-0100-3389
Refer to Startup and calibration. If the sensor appears to respond sluggishly to pH change, soaking it overnight in a weak acid solution (5% hydrochloric acid) may improve its response. Be sure to follow the Warning above and to rinse the sensor's tip thoroughly with tap water. If the sensor will not calibrate, it must be replaced.

4.2 Automatic temperature compensator

The temperature compensator element is a temperature sensitive resistor and can be checked with an ohmeter. Resistance increases with temperature.
The 3K element reads 3000 ohms ±1% at 77 °F (25 °C), and a Pt100 reads 110 ohms. Resistance varies with temperature for a 3K and Pt-100 element and can be determined according to Table 4-2 or the following formula:
RT = RO [1 + R1(T-20)]
Where RT = Resistance and T = Temperature in °C
Refer to Table 4-1 for RO and R1 values.
Table 4-1: RO and R1 Values for Temperature Compensation Elements
Temperature compensation element
3K 2934 0.0045
PT-100 107.7 0.00385
R
O
R
1
Table 4-2: Temperature vs. Resistance of Auto T.C. Elements
Temperature °C Resistance (Ohms) ±1%
3K PT-100
0 26270 100.0
10 2802 103.8
20 2934 107.7
25 3000 109.6
30 3066 111.5
40 3198 115.4
50 3330 119.2
60 3462 123.1
70 3594 126.9
80 3726 130.8
90 3858 134.6
100 3990 138.5
32 Rosemount 389/389VP
Page 33
Reference Manual Maintenance
00809-0100-3389 February 2019

4.3 ORP

4.3.1 Check platinum electrode

Check the platinum electrode as follows. There are two types of standard solutions which may be used to check the ORP electrode/transmitter system.
Type 1: One type of commonly used ORP standard solution is the saturated quinhydrone solution (PN R508-16OZ). Refer to Rosemount™ 389/389VP ORP calibration.
WARNING
The solution used during the following check is an acid.
Handle the solution with care. Follow the manufacturer's directions. Wear the proper protective equipment. If contact with skin or clothing is made, immediately rinse with plenty of clean water.
4.3.2
Type 2: A second ORP standard solution can be prepared from the following recipe:
Procedure
1. Dissolve 39.2 grams of reagent grade ferrous ammonium sulfate, Fe(NH4)2(SO4)2 6H2O and 48.2 grams of reagent grade ferric ammonium sulfate, FeNH4(SO4)2 12 H2O in approximately 700 ml of water.
Distilled water is preferred, but tap water is acceptable.
2. Slowly and carefully add 56.2 ml of concentrated sulfuric acid.
3. Add sufficient water to bring the total solution volume up to 1000 ml.
This standard ORP solution, although not as simple to prepare as the quinhydrone recipe, is much more stable and will maintain its millivolt value for approximately one year when stored in glass containers. This solution (ferric/ferrous ammonium sulfate) produces a nominal ORO of 476 +20 mV at 77 °F (25 ºC) when used with a saturated KCL/AgCl reference electrode and platinum measuring electrode. Some tolerance in mV values is to be expected due to the rather large liquid reference junction potentials that can arise when measuring this strongly acidic and concentrated solution. However, if measuring electrodes are kept clean and in good operating condition, consistently repeatable calibrations can be carried out using this standard solution.

Cleaning platinum electrode

To restore the electrode to normal operation, clean the platinum electrode with baking soda. Polish it by rubbing it with a damp paper towel and baking soda until it appears bright and shiny.
Reference Manual 33
Page 34
Maintenance Reference Manual
February 2019 00809-0100-3389
34 Rosemount 389/389VP
Page 35
Reference Manual Troubleshooting
00809-0100-3389 February 2019

5 Troubleshooting

Table 5-1: Troubleshooting
Trouble Probable Cause Remedy
Meter reads off scale (Display reads overrange).
Display reads between 3 and 6 pH regardless of actual pH of solution or sample.
Meter or display indication swings or jumps widely in AUTO T.C. Mode.
Span between buffers extremely short in AUTO T.C. Mode.
Sluggish or slow meter indication for real changes in pH level.
Defective preamplifier. Replace preamplifier (for code 02
sensors). For code 01, replace sensor.
T.C. element shorted Check T.C. element as instructed in
Automatic temperature compensator
and replace sensor if defective.
Sensor not in process or sample stream is low.
Open glass electrode. Replace sensor.
Reference element open - no contact. Replace sensor.
Electrode cracked. Replace sensor.
T.C. element shorted. Check T.Cl. element as instructed in
T.C. element shorted. Check T.Cl. element as instructed in
Electrode cracked. Clean sensor as instructed in Clean
Make sure sensor is in process with sufficient sample stream (refer to
Install for installation details).
Automatic temperature compensator
and replace sensor if defective.
Automatic temperature compensator
and replace sensor if defective.
electrode or Cleaning platinum electrode. Replace sensor if cracked.
Electrode defective. Replace sensor.
Transmitter cannot be standardized. Electrode coated or cracked. Clean sensor as instructed in Clean
electrode or Cleaning platinum electrode. Replace sensor if cracked.
Defective preamplifier Replace preamplifier.
Transmitter short spans between two different buffer values.
Reference Manual 35
Old glass electrode or high temperature exposure.
Coated glass. Clean sensor as instructed in Clean
Replace sensor.
electrode or Cleaning platinum electrode. Replace sensor if cracked.
Page 36
Troubleshooting Reference Manual
February 2019 00809-0100-3389
Table 5-2: Rosemount 389/389VP pH/ORP Sensor Accessories Information
Part number Description
11275-01 Handrail mounting assembly
12707-00 Jet spray cleaner
2002011 CPVC in-line tee, 1.5 in. size, 1.0 in. threaded process connection ends
915240-03 PVC in-line tee, 2.0 in. size, 3/4 in. threaded process connection ends
915240-04 PVC in-line tee, 2.0 in. size, 1.0 in. threaded process connection ends
915240-05 PVC in-line tee, 2.0 in. size, 1.5 in. threaded process connection ends
23242-02 Insertion mounting adapter, 1.5 in. MNPT process connection, 1 in. x 3/4 in. FPT sensor
adapter/union thread size
33081-00 PEEK adapter insert, 1 x 3/4 in., for 23242-02
23646-01 11-conductor extension cable, shielded and prepped (for use with remote junction box)
9200273 11-conductor extension cable, shielded and unprepped (for use with remote junction box)
24091-00 Low flow cell, 1 in. sensor threaded connectio, 1/4 in. process connection
23555-00 Weatherproof junction box with preamplifier
2002565 Mounting bracket kit
9210012 pH 4.01 buffer solution, 16 oz
9210013 pH 6.86 buffer solution, 16 oz
9210014 pH 9.18 buffer solution, 16 oz
24281-00 15 ft VP8 cable
24281-01 25 ft VP8 cable
24281-02 2.5 ft VP8 cable
24281-03 50 ft VP8 cable
24281-04 100 ft VP8 cable
24281-05 4 ft VP8 cable
24281-06 10 ft VP8 cable
24281-07 20 ft VP8 cable
24281-08 30 ft VP8 cable
36 Rosemount 389/389VP
Page 37
Reference Manual Return of Material
00809-0100-3389 February 2019

6 Return of Material

For all repair or return of material requests, please contact the factory.
Reference Manual 37
Page 38
Return of Material Reference Manual
February 2019 00809-0100-3389
38 Rosemount 389/389VP
Page 39
Reference Manual EC Declaration of Conformity
00809-0100-3389 February 2019

A EC Declaration of Conformity

Reference Manual 39
Page 40
EC Declaration of Conformity Reference Manual
February 2019 00809-0100-3389
40 Rosemount 389/389VP
Page 41
Reference Manual EC Declaration of Conformity
00809-0100-3389 February 2019
Reference Manual 41
Page 42
EC Declaration of Conformity Reference Manual
February 2019 00809-0100-3389
42 Rosemount 389/389VP
Page 43
Reference Manual China RoHS Table
00809-0100-3389 February 2019

B China RoHS Table

Reference Manual 43
Page 44
China RoHS Table Reference Manual
February 2019 00809-0100-3389
44 Rosemount 389/389VP
Page 45
Reference Manual Intrinsically Safe Sensor Installation Drawing - FM
00809-0100-3389 February 2019
C Intrinsically Safe Sensor Installation
Drawing - FM
Reference Manual 45
Page 46
00809-0100-3389
Rev. AA
2019
GLOBAL HEADQUARTERS
Emerson Automation Solutions 6021 Innovation Blvd Shakopee, MN 55379, USA
+1 800 999 9307 or +1 952 906 8888 F +1 952 949 7001 liquid.csc@emerson.com
EUROPE
Emerson Automation Solutions Neuhofstrasse 19a P.O. Box 1046 CH-6340 Baar Switzerland
T + 41 (0) 41 768 6111 F + 41 (0) 41 768 6300 liquid.csc@emerson.com
Linkedin.com/company/Emerson-Automation-Solutions
twitter.com/rosemount_news
Facebook.com/Rosemount
youtube.com/RosemountMeasurement
google.com/+RosemountMeasurement
NORTH AMERICA
Emerson Automation Solutions 8200 Market Blvd Chanhassen, MN 55317
Toll Free +1 800 999 9307 F +1 952 949 7001 liquid.csc@emerson.com
MIDDLE EAST AND AFRICA
Emerson Automation Solutions Emerson FZE Jebel Ali Free Zone Dubai, United Arab Emirates, P.O. Box 17033
T +971 4 811 8100 F +971 4 886 5465 liquid.csc@emerson.com
©
2019 Emerson. All rights reserved.
The Emerson logo is a trademark and service mark of Emerson Electric Co. Rosemount is a mark of one of the Emerson family of companies. All other marks are the property of their respective owners.
ASIA-PACIFIC
Emerson Automation Solutions 1 Pandan Crescent Singapore 128461 Singapore
T +65 777 8211 F +65 777 0947 liquid.csc@emerson.com
Loading...