Instruction manual

ManualsBrandsEmerson ManualsConsumer electronicsSolu Comp Xmt-P-FF/FI

Model Solu Comp Xmt-P

pH, ORP, and Redox Transmitter

Instruction Manual

PN 51-Xmt-P/rev.E

October 2007

Summary of content (124 pages)

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Instruction Manual PN 51-Xmt-P/rev.
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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.
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QUICK START GUIDE FOR MODEL SOLU COMP Xmt-P TRANSMITTER 1. Refer to page 11 for installation instructions. 2. Wire pH or ORP sensor to the transmitter. See Figure 2-3 for panel mount; Figure 2-4 or 2-5 for pipe or surface mount. Refer to the sensor instruction sheet for details. 3. Once connections are secure and verified, apply power to the transmitter. 4. When the transmitter is powered up for the first time, Quick Start screens appear. Using Quick Start is easy. a.
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MODEL XMT-P pH/ORP TABLE OF CONTENTS MODEL XMT-P pH/ORP TWO-WIRE TRANSMITTER TABLE OF CONTENTS Section 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10 Title DESCRIPTION AND SPECIFICATIONS ................................................................ Features and Applications........................................................................................ Specifications ...........................................................................................................
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MODEL XMT-P pH/ORP TABLE OF CONTENTS TABLE OF CONTENTS CONT’D 8.0 8.1 8.2 CALIBRATION — TEMPERATURE........................................................................ Introduction .............................................................................................................. Calibrating Temperature........................................................................................... 79 79 79 9.0 9.1 9.2 9.3 9.4 9.5 9.6 CALIBRATION — pH ........................................
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MODEL XMT-P pH/ORP TABLE OF CONTENTS TABLE OF CONTENTS CONT’D 13.0 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 ORP MEASUREMENTS.......................................................................................... General .................................................................................................................... Measuring Electrode ................................................................................................ Reference Electrode .................................
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MODEL XMT-P pH/ORP TABLE OF CONTENTS LIST OF FIGURES Number 1-1 1-2 1-3 1-4 1-5 2-1 2-2 2-3 2-4 2-5 3-1 3-2 3-3 3-4 3-5 4-1 4-2 4-3 4-4 4-5 4-6 4-7 4-8 4-9 4-10 4-11 4-12 4-13 4-14 4-15 4-16 4-17 4-18 4-19 4-20 4-21 4-22 4-23 4-24 4-25 4-26 4-27 5-1 5-2 5-3 5-4 6-1 6-2 6-3 Title Menu Tree — Xmt-P-HT........................................................................................... Menu Tree — Xmt-P-FF ...........................................................................................
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MODEL XMT-P pH/ORP TABLE OF CONTENTS LIST OF FIGURES CONT’D Number Title 9-1 10-1 10-2 10-3 10-4 12-1 12-2 12-3 12-4 12-5 12-6 12-7 12-8 13-1 13-2 13-3 13-4 13-5 13-6 14-1 14-2 Page Calibration Slope and Offset .................................................................................... Simulate pH.............................................................................................................. Three-Wire RTD Configuration.............................................................
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MODEL XMT-P pH/ORP SECTION 1.0 DESCRIPTION AND SPECIFICATIONS SECTION 1.
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MODEL XMT-P pH/ORP SECTION 1.0 DESCRIPTION AND SPECIFICATIONS 1.2 SPECIFICATIONS 1.2.1 GENERAL SPECIFICATIONS Case: ABS (panel mount), polycarbonate (pipe/wall mount); NEMA 4X/CSA 4 (IP65) Dimensions Panel (code -10): 6.10 x 6.10 x 3.72 in. (155 x 155 x 94.5 mm) Surface/Pipe (code -11): 6.23 x 6.23 x 3.23 in. (158 x 158 x 82 mm); see page 15 for dimensions of pipe mounting bracket. Conduit openings: Accepts PG13.5 or 1/2 in. conduit fittings Ambient Temperature: 32 to 122°F (0 to 50°C).
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MODEL XMT-P pH/ORP SECTION 1.0 DESCRIPTION AND SPECIFICATIONS 1.2.2 FUNCTIONAL SPECIFICATIONS pH Range: 0 to 14 ORP Range: -1400 to +1400mV Calibrations/standardization: The automatic buffer recognition uses stored buffer values and their temperature curves for the most common buffer standards available worldwide. The transmitter also performs a stabilization check on the sensor in each buffer.
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MODEL XMT-P pH/ORP SECTION 1.0 DESCRIPTION AND SPECIFICATIONS 1.3 HAZARDOUS LOCATION APPROVALS Intrinsic Safety: Class I, II, III, Div. 1 Groups A-G T4 Tamb = 50°C Class I, II, III, Div. 1 Groups A-G T4 Tamb = 50°C ATEX 1180 II 1 G Baseefa04ATEX0213X EEx ia IIC T4 Tamb = 0°C to 50°C Non-Incendive: Class I, Div. 2, Groups A-D Dust Ignition Proof Class II & III, Div. 1, Groups E-G NEMA 4/4X Enclosure Class I, Div. 2, Groups A-D Dust Ignition Proof Class II & III, Div.
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MODEL XMT-P pH/ORP SECTION 1.0 DESCRIPTION AND SPECIFICATIONS Language FIGURE 1-1. MENU TREE FOR MODEL SOLU COMP Xmt-P-HT TRANSMITTER 1.
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MODEL XMT-P pH/ORP SECTION 1.0 DESCRIPTION AND SPECIFICATIONS 6 Language FIGURE 1-2. MENU TREE FOR MODEL SOLU COMP Xmt-P-FF TRANSMITTER 1.
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MODEL XMT-P pH/ORP SECTION 1.0 DESCRIPTION AND SPECIFICATIONS 1.6 HART COMMUNICATIONS 1.6.1 OVERVIEW OF HART COMMUNICATION HART (highway addressable remote transducer) is a digital communication system in which two frequencies are superimposed on the 4 to 20 mA output signal from the transmitter. A 1200 Hz sine wave represents the digit 1, and a 2400 Hz sine wave represents the digit 0. Because the average value of a sine wave is zero, the digital signal adds no dc component to the analog signal.
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MODEL XMT-P pH/ORP SECTION 1.0 DESCRIPTION AND SPECIFICATIONS Model Xmt-P FIGURE 1-4. HART Communicators. Both the Rosemount Model 375 (or 275) and a computer can be used to communicate with a HART transmitter. The 250 ohm load (minimum) must be present between the transmitter and the power supply. 1.
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MODEL XMT-P pH/ORP SECTION 1.0 DESCRIPTION AND SPECIFICATIONS FIGURE 1-5.
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MODEL XMT-P pH/ORP SECTION 1.0 DESCRIPTION AND SPECIFICATIONS 1.9 ORDERING INFORMATION The Solu Comp Model Xmt Two-Wire Transmitter is intended for the determination of pH, ORP, or Redox.
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MODEL XMT-P pH/ORP SECTION 2.0 INSTALLATION SECTION 2.0 INSTALLATION 2.1 2.2 2.3 Unpacking and Inspection Pre-Installation Set Up Installation 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.
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MODEL XMT-P pH/ORP SECTION 2.0 INSTALLATION 2.2.3 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.
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MODEL XMT-P pH/ORP SECTION 2.0 INSTALLATION 2.3 INSTALLATION 1. Although the transmitter is suitable for outdoor use, do not install it in direct sunlight or in areas of extreme temperatures. 2. Install the transmitter in an area where vibrations and electromagnetic and radio frequency interference are minimized or absent. 3. Keep the transmitter and sensor wiring at least one foot from high voltage conductors. Be sure there is easy access to the transmitter. 4.
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MODEL XMT-P pH/ORP SECTION 2.0 INSTALLATION Panel Mounting. MILLIMETER INCH FIGURE 2-3. Panel Mount Installation Access to the wiring terminals is through the rear cover. Four screws hold the cover in place.
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MODEL XMT-P pH/ORP SECTION 2.0 INSTALLATION Pipe Mounting. MILLIMETER INCH FIGURE 2-4. Pipe Mount Installation The front panel is hinged at the bottom. The panel swings down for access to the wiring terminals.
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MODEL XMT-P pH/ORP SECTION 2.0 INSTALLATION Surface Mounting. MILLIMETER INCH FIGURE 2-5. Surface Mount Installation The front panel is hinged at the bottom. The panel swings down for access to the wiring terminals.
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MODEL XMT-P pH/ORP SECTION 3.0 WIRING SECTION 3.0 WIRING 3.1 POWER SUPPLY/CURRENT LOOP — MODEL XMT-P-HT 3.1.1 Power Supply and Load Requirements. Refer to Figure 3-1. The supply voltage must be at least 12.0 Vdc at the transmitter terminals. The power supply must be able to cover the voltage drop on the cable as well as the load resistor (250 Ω minimum) required for HART communications. The maximum power supply voltage is 42.0 Vdc.
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MODEL XMT-P pH/ORP 3.2 SECTION 3.0 WIRING POWER SUPPLY WIRING FOR MODEL XMT-P-FF 3.2.1 Power Supply Wiring. Refer to Figure 3-3 and Figure 3-4. Run the power/signal wiring through the opening nearest TB2. Use shielded cable and ground the shield at the power supply. To ground the transmitter, attach the shield to TB2-3. NOTE For optimum EMI/RFI immunity, the power supply/output cable should be shielded and enclosed in an earth-grounded metal conduit.
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MODEL XMT-P pH/ORP SECTION 3.0 WIRING 3.3 SENSOR WIRING 3.3.1 Sensor Wiring Information pH and ORP sensors manufactured by Rosemount Analytical can be wired to the Model XMT-P transmitter 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. See Section 7.4.3 for set-up.
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MODEL XMT-P pH/ORP SECTION 4.0 INTRINSICALLY SAFE INSTALLATION SECTION 4.0 INTRINSICALLY SAFE INSTALLATION INTRINSICALLY SAFE INSTALLATIONS FOR MODEL XMT-P-HT For CSA Instrinsically Safe Installation, see Figure 4-4. For ATEX Instrinsically Safe Label, see Figure 4-5. For ATEX Instrinsically Safe Installation, see Figure 4-6. FIGURE 4-1. FM Intrinsically Safe Label for Model Xmt-P-HT For FM Intrinsically Safe Label, see Figure 4-1. For FM Intrinsically Safe Installation, see Figure 4-2.
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21 FIGURE 4-2.
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22 FIGURE 4-3.
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23 FIGURE 4-4.
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24 FIGURE 4-5.
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25 FIGURE 4-6.
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26 FIGURE 4-7.
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27 FIGURE 4-8.
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28 FIGURE 4-9.
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R Analytical FM MATERIAL: 3M SCOTCHCAL #3650-10 (WHITE VINYL FACESTOCK) OR POLYESTER, (.002 REFERENCE THICKNESS CLEAR MATTE MYLAR OVERLAMINATE, .002-.005 FINISH THICKNESS. PRESSURE SENSITIVE ADHESIVE, FARSIDE AND SPLIT LINER) OR (INTERMEC PN L7211210, 2 MIL GLOSS WHITE POLYESTER WITH PRESSURE SENSITIVE ACRYLIC ADHESIVE. NOMENCLATURE TO BE PRINTED USING INTERMEC SUPER PREMIUM BLACK THERMAL TRANSFER RIBBON) SEE BLANK LABEL PN 9241406-01. ARTWORK IS SHEET 2 OF 2. 2 1.
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8 MODEL XMT-P-FF XMTR 6 1 2 3 4 5 6 7 8 9 10 11 12 5 8 NOTES: UNLESS OTHERWISE SPECIFIED Voc OR Vt NOT GREATER THAN 30 V Isc OR It NOT GREATER THAN 200 mA Pmax NOT GREATER THAN 0.9 W 7 5 9064 ECO NO. RELEASE DATE 30 375 10-6-04 Vmax IN: Vdc MODEL NO. Vmax (Vdc) 30 4 TABLE III 7.97 2.974 0.974 La (mH) REV A Ci (nF) 0.4 Pmax (W) 1.3 0 Li (mH) 511.59mW 157.17mA 13.03V FINISH ANGLES TOLERANCES + 1/2 - 3 DIMENSIONS ARE IN INCHES REMOVE BURRS & SHARP EDGES .
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8 PREAMP (NOTE 4) 6 MODEL XMT-P-FF XMTR 5 5 3 2 1 MODEL XMT-P-FF XMTR MODEL XMT-P-FF XMTR MODEL XMT-P-FF XMTR 4 IS CLASS I, II, III, DIVISION 1, GROUPS A, B, C, D, E, F, G; HAZARDOUS AREA 4 3 3 SAFETY BARRIER (SEE NOTES 1 & 9) SAFETY BARRIER (SEE NOTES 1 & 9) SAFETY BARRIER (SEE NOTES 1 & 9) SAFETY BARRIER (SEE NOTES 1 & 9) FIGURE 4-12.
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32 R Analytical R -LR 34186 MATERIAL: 3M SCOTCHCAL #3650-10 (WHITE VINYL FACESTOCK) OR POLYESTER, (.002 REFERENCE THICKNESS CLEAR MATTE MYLAR OVERLAMINATE, .002-.005 FINISH THICKNESS. PRESSURE SENSITIVE ADHESIVE, FARSIDE AND SPLIT LINER) OR (INTERMEC PN L7211210, 2 MIL GLOSS WHITE POLYESTER WITH PRESSURE SENSITIVE ACRYLIC ADHESIVE. NOMENCLATURE TO BE PRINTED USING INTERMEC SUPER PREMIUM BLACK THERMAL TRANSFER RIBBON) SEE BLANK LABEL PN 9241406-01. ARTWORK IS SHEET 2 OF 2. 2 1.
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MODEL XMT-P-FF XMTR 6 1 2 3 4 5 6 7 8 9 10 11 12 5 8 NOTES: UNLESS OTHERWISE SPECIFIED Voc OR Vt NOT GREATER THAN 30 V Isc OR It NOT GREATER THAN 300 mA Pmax NOT GREATER THAN 1.3 W 7 5 30 375 4 ECO NO. 9047 Vmax IN: Vdc Vmax (Vdc) MODEL NO. RELEASE DATE TABLE III 7.97 2.974 0.974 La (mH) REV A Ci (nF) 0.4 Pmax (W) 1.3 Po Io Uo 0 Li (mH) 511.59mW 157.17mA 13.
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8 PREAMP (NOTE 4) 6 MODEL XMT-P-FF XMTR 5 5 3 2 1 MODEL XMT-P-FF XMTR MODEL XMT-P-FF XMTR MODEL XMT-P-FF XMTR 4 IS CLASS I, GRPS A-D CLASS II, GRPS E-G CLASS III HAZARDOUS AREA 4 3 3 SAFETY BARRIER (SEE NOTES 1 & 9) SAFETY BARRIER (SEE NOTES 1 & 9) SAFETY BARRIER (SEE NOTES 1 & 9) SAFETY BARRIER (SEE NOTES 1 & 9) FIGURE 4-15.
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R SUPPLY BAS04ATEX0213X EEx ia IIC T4 Tamb = 0°C TO +50°C ALL ALPHA AND NUMERIC CHARACTERS ON LABEL TO BE BLACK HELVETICA MEDIUM. BACKGROUND TO BE WHITE. MATERIAL: 3M SCOTCHCAL #3650-10 (WHITE VINYL FACESTOCK) OR POLYESTER, (.002 REFERENCE THICKNESS CLEAR MATTE MYLAR OVERLAMINATE, .002-.005 FINISH THICKNESS. PRESSURE SENSITIVE ADHESIVE, FARSIDE AND SPLIT LINER). ARTWORK IS SHEET 2 OF 2. 3. 2 1. NOTES: UNLESS OTHERWISE SPECIFIED NO CHANGE WITHOUT Baseefa APPROVAL.
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A B C D 36 8 7 6 8 NOTES: UNLESS OTHERWISE SPECIFIED 7 5.5nF 0mH Ci Li 30 0.4 0 1.0 Wamx IN: W ECO NO. RELEASE DATE 4 9065 6-30-05 Baseefa Certified Product No modifications permitted without the approval of the Authorized Person Related Drawing 200 Imax IN:mA A REV 0.0 Li (mH) FINISH ANGLES TOLERANCES + 1/2 DIMENSIONS ARE IN INCHES 3 REMOVE BURRS & SHARP EDGES .020MAX MACHINED FILLET RADII .020 MAX NOMINAL SURFACE FINISH 125 + - .030 + .010 - MATERIAL .XX .
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7 PREAMP (NOTE 4) PH SENSOR WITH TC 4 (ZONE 0) 3 3 SAFETY BARRIER (SEE NOTES 1 & 9) SAFETY BARRIER (SEE NOTES 1 & 9) SAFETY BARRIER (SEE NOTES 1 & 9) SAFETY BARRIER (SEE NOTES 1 & 9) FIGURE 4-18. ATEX Intrinsically Safe Installation (1 of 2) for Model Xmt-P-FF 5 TO PREVENT IGNITION OF FLAMMABLE OR COMBUSTIBLE ATMOSPHERES, DISCONNECT POWER BEFORE SERVICING. WARNING6 SUBSTITUTION OF COMPONENTS MAY IMPAIR INTRINSIC SAFETY OR SUITABILITY FOR DIVISION 2.
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38 R Analytical APPROVED FM MATERIAL: 3M SCOTCHCAL #3650-10 (WHITE VINYL FACESTOCK) OR POLYESTER, (.002 REFERENCE THICKNESS CLEAR MATTE MYLAR OVERLAMINATE, .002-.005 FINISH THICKNESS. PRESSURE SENSITIVE ADHESIVE, FARSIDE AND SPLIT LINER) OR (INTERMEC PN L7211210, 2 MIL GLOSS WHITE POLYESTER WITH PRESSURE SENSITIVE ACRYLIC ADHESIVE. NOMENCLATURE TO BE PRINTED USING INTERMEC SUPER PREMIUM BLACK THERMAL TRASFER RIBBON). SEE BLANK LABEL PN 9241406-01). ARTWORK IS SHEET 2 OF 2. 2 1.
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MODEL XMT-P-FI XMTR 6 1 2 3 4 5 6 7 8 9 10 11 12 5 8 NOTES: UNLESS OTHERWISE SPECIFIED Voc OR Vt NOT GREATER THAN 30 V Isc OR It NOT GREATER THAN 200 mA Pmax NOT GREATER THAN 0.9 W 7 5 TABLE I 4 ECO NO. 9064 30 17.5 Vmax (Vdc) 375 RELEASE DATE TABLE III 59.97 29.97 7.97 La (mH) REV A 5.32 Pmax (W) Po Io Uo Li (mH) 0 Ci (nF) 0.4 208.96mW 64.15mA 13.03V MODEL XMT-P-FI TB1-1 THRU 12 FINISH ANGLES TOLERANCES + 1/2 - 3 DIMENSIONS ARE IN INCHES REMOVE BURRS & SHARP EDGES .
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8 PREAMP (NOTE 4) 6 MODEL XMT-P-FI XMTR 5 5 3 2 1 MODEL XMT-P-FI XMTR MODEL XMT-P-FI XMTR MODEL XMT-P-FI XMTR 4 IS CLASS I, II, III, DIVISION 1, GROUPS A, B, C, D, E, F, G; HAZARDOUS AREA 4 3 3 SAFETY BARRIER (SEE NOTES 1 & 9) SAFETY BARRIER (SEE NOTES 1 & 9) SAFETY BARRIER (SEE NOTES 1 & 9) SAFETY BARRIER (SEE NOTES 1 & 9) FIGURE 4-21.
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R Analytical R -LR 34186 MATERIAL: 3M SCOTCHCAL #3650-10 (WHITE VINYL FACESTOCK) OR POLYESTER, (.002 REFERENCE THICKNESS CLEAR MATTE MYLAR OVERLAMINATE, .002-.005 FINISH THICKNESS. PRESSURE SENSITIVE ADHESIVE, FARSIDE AND SPLIT LINER) OR (INTERMEC PN L7211210, 2 MIL GLOSS WHITE POLYESTER WITH PRESSURE SENSITIVE ACRYLIC ADHESIVE. NOMENCLATURE TO BE PRINTED USING INTERMEC SUPER PREMIUM BLACK THERMAL TRASFER RIBBON). SEE BLANK LABEL PN 9241406-01). ARTWORK IS SHEET 2 OF 2. 2 1.
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C D 8 MODEL XMT-P-FI XMTR 6 1 2 3 4 5 6 7 8 9 10 11 12 5 8 NOTES: UNLESS OTHERWISE SPECIFIED 7 5 4 ECO NO. 9047 30 17.5 Vmax (Vdc) 375 RELEASE DATE TABLE III 59.97 29.97 7.97 La (mH) REV A TABLE II 0.4 5.32 0 Li (mH) FINISH + 1/2 DIMENSIONS ARE IN INCHES ANGLES TOLERANCES 3 REMOVE BURRS & SHARP EDGES .020MAX MACHINED FILLET RADII .020 MAX NOMINAL SURFACE FINISH 125 + - .030 + .010 - MATERIAL .XX .XXX DATE 10/6/04 2 THIS DWG CONVERTED TO SOLID EDGE J.
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8 PREAMP (NOTE 3) 6 MODEL XMT-P-FI XMTR 5 5 3 2 1 MODEL XMT-P-FI XMTR MODEL XMT-P-FI XMTR MODEL XMT-P-FI XMTR 4 IS CLASS I, GRPS A-D CLASS II, GRPS E-G CLASS III HAZARDOUS AREA 4 3 3 SAFETY BARRIER (SEE NOTE 8) SAFETY BARRIER (SEE NOTE 8) SAFETY BARRIER (SEE NOTE 8) SAFETY BARRIER (SEE NOTE 8) FIGURE 4-24.
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44 R SUPPLY BAS04ATEX0213X EEx ia IIC T4 Tamb = 0°C TO +50°C ALL ALPHA AND NUMERIC CHARACTERS ON LABEL TO BE BLACK HELVETICA MEDIUM. BACKGROUND TO BE WHITE. MATERIAL: 3M SCOTCHCAL #3650-10 (WHITE VINYL FACESTOCK) OR POLYESTER, (.002 REFERENCE THICKNESS CLEAR MATTE MYLAR OVERLAMINATE, .002-.005 FINISH THICKNESS. PRESSURE SENSITIVE ADHESIVE, FARSIDE AND SPLIT LINER). ARTWORK IS SHEET 2 OF 2. 3. 2 1. NOTES: UNLESS OTHERWISE SPECIFIED NO CHANGE WITHOUT Baseefa APPROVAL.
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A B C D 8 7 6 40 6.5 23.2 IIB IIA Vmax IN: Vdc 30 375 8 NOTES: UNLESS OTHERWISE SPECIFIED 7 5 5.32 0.4 Ci (uF) 0 Li (uH) Wamx IN: W 1.0 4 RELEASE DATE 6-30-05 ECO NO. 9065 Baseefa Certified Product No modifications permitted without the approval of the Authorized Person Related Drawing Imax IN:mA 200 REV A 0.0 Li (mH) FINISH + 1/2 DIMENSIONS ARE IN INCHES ANGLES TOLERANCES 3 REMOVE BURRS & SHARP EDGES .020MAX MACHINED FILLET RADII .
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PH SENSOR WITH TC AMPEROMETRIC SENSOR 7 PREAMP (NOTE 4) 4 (ZONE 0) 3 3 SAFETY BARRIER (SEE NOTES 1 & 9) SAFETY BARRIER (SEE NOTES 1 & 9) SAFETY BARRIER (SEE NOTES 1 & 9) SAFETY BARRIER (SEE NOTES 1 & 9) FIGURE 4-27. ATEX Intrinsically Safe Installation (2 of 2) for Model Xmt-P-FI 5 TO PREVENT IGNITION OF FLAMMABLE OR COMBUSTIBLE ATMOSPHERES, DISCONNECT POWER BEFORE SERVICING. WARNING6 SUBSTITUTION OF COMPONENTS MAY IMPAIR INTRINSIC SAFETY OR SUITABILITY FOR DIVISION 2.
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MODEL XMT-P pH/ORP SECTION 5.0 DISPLAY AND OPERATION SECTION 5.0 DISPLAY AND OPERATION 5.1. DISPLAY The Model Xmt-P has a two-line display. Generally, the user can program the transmitter to show one of three displays. If the transmitter has been configured to measure ORP or Redox, similar displays are available. Figure 5-1 shows the displays available for pH. The transmitter has information screens that supplement the data in the main display. Press q to view the information screens.
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MODEL XMT-P pH/ORP SECTION 5.0 DISPLAY AND OPERATION 5.3 PROGRAMMING AND CALIBRATING THE MODEL XMT - TUTORIAL Setting up and calibrating the Model Xmt is easy. The following tutorial describes how to move around in the programming menus. For practice, the tutorial also describes how to assign values to the 4 and 20 mA output. Calibrate Program Calibrate Program Output Measurement Security Hold Display Hold Display Temp >> HART >> Noise Rejection ResetAnalyzer >> 1.
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MODEL XMT-P pH/ORP SECTION 5.0 DISPLAY AND OPERATION 5.4 MENU TREES - pH The Model Xmt-P pH transmitter has four menus: CALIBRATE, PROGRAM, HOLD, and DISPLAY. Under the Calibrate and Program menus are several sub-menus. For example, under CALIBRATE, the sub-menus are Temperature and pH or ORP/Redox. Under each sub-menu are prompts. Under PROGRAM, the sub-menus for Xmt-P-HT are Output, Temp, Measurement, Security, HART, Diagnostics, Noise Rejection, and Reset Analyzer.
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FIGURE 5-3. MENU TREE FOR MODEL SOLU COMP Xmt-P-HT TRANSMITTER MODEL XMT-P pH/ORP 50 SECTION 5.
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FIGURE 5-4. MENU TREE FOR MODEL SOLU COMP Xmt-P-FF TRANSMITTER MODEL XMT-P pH/ORP SECTION 5.
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MODEL XMT-P pH/ORP SECTION 5.0 DISPLAY AND OPERATION 5.6 SECURITY 5.6.1 How the Security Code Works Use security codes to prevent accidental or unwanted changes to program settings, displays, and calibration. Two three-digit security codes can be used to do the following… a. Allow a user to view the default display and information screens only. b. Allow a user access to the calibration and hold menus only. c. Allow a user access to all the menus. Enter Security Code: 000 1.
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MODEL XMT-P pH/ORP SECTION 6.0 OPERATION WITH MODEL 375 SECTION 6.0 OPERATION WITH MODEL 375 6.1 Note on Model 375 HART and Foundation Fieldbus Communicator The Model 375 HART Communicator is a product of Emerson Process Management, Rosemount Inc. This section contains selected information on using the Model 375 with the Rosemount Analytical Model Xmt-P-HT Transmitter and Model Xmt-P-FF Transmitter. For complete information on the Model 375 Communicator, see the Model 375 instruction manual.
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MODEL XMT-P pH/ORP SECTION 6.0 OPERATION WITH MODEL 375 6.3 Operation 6.3.1 Off-line and On-line Operation The Model 375 Communicator features off-line and on-line communications. On-line means the communicator is connected to the transmitter in the usual fashion. While the communicator is on line, the operator can view measurement data, change program settings, and read diagnostic messages. Off-line means the communicator is not connected to the transmitter.
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MODEL XMT-P pH/ORP SECTION 6.0 OPERATION WITH MODEL 375 Device setup FIGURE 6-2.
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MODEL XMT-P pH/ORP 56 SECTION 6.0 OPERATION WITH MODEL 375 Temp mode [Live, Manual] (1) FIGURE 6-2.
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MODEL XMT-P pH/ORP SECTION 6.0 OPERATION WITH MODEL 375 RESOURCE FIGURE 6-3.
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MODEL XMT-P pH/ORP SECTION 6.0 OPERATION WITH MODEL 375 TRANSDUCER FIGURE 6-3.
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MODEL XMT-P pH/ORP Glass fault low setpoint Glass warn high setpoint Glass warn low setpoint Temperature Compensation Secondary value units Sensor temp comp Sensor temp manual Temp Sensor Ohms Sensor type temp Sensor connection Operating isopot ph Isopotential pH Temperature coeff Reset transducer/Load factory defaults Identification Software version Hardware version LOI config code LOI calibration code Sensor S/N Final assembly number SIMULATION PV Simulate value PV Simulation Faults Warnings Additional T
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MODEL XMT-P pH/ORP LOW_CUT SIMULATE: Simulate Status SIMULATE: Simulate Value SIMULATE: Transducer Status SIMULATE: Transducer Value SIMULATE: Simulate En/Disable ST_REV STATUS_OPTS STRATEGY XD_SCALE: EU at 100% XD_SCALE: EU at 0% XD_SCALE: Units Index XD_SCALE: Decimal I/O References AI Channel Connectors Out: Status Out: Value Online BLOCK_ERR FIELD_VAL: Status FIELD_VAL: Value MODE_BLK: Target MODE_BLK: Actual MODE_BLK: Permitted MODE_BLK: Normal Out: Status Out: Value PV: Status PV: Value Status BLOCK_
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MODEL XMT-P pH/ORP OUT_SCALE: EU at 100% OUT_SCALE: EU at 0% OUT_SCALE: Units Index OUT_SCALE: Decimal GRANT_DENY: Grant GRANT_DENY: Deny IO_OPTS STATUS_OPTS AI Channel LOW_CUT PV_FTIME FIELD_VAL: Status FIELD_VAL: Value UPDATE_EVT: Unacknowledged UPDATE_EVT: Update State UPDATE_EVT: Time Stamp UPDATE_EVT: Static Rev UPDATE_EVT: Relative Index BLOCK_ALM: Unacknowledged BLOCK_ALM: Alarm State BLOCK_ALM: Time Stamp BLOCK_ALM: Subcode BLOCK_ALM: Value ALARM_SUM: Unacknowledged ALARM_SUM: Unreported ALARM_SUM:
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MODEL XMT-P pH/ORP SECTION 6.0 OPERATION WITH MODEL 375 DV_LO_LIM FIGURE 6-3.
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MODEL XMT-P pH/ORP SECTION 6.0 OPERATION WITH MODEL 375 TRK_SCALE: Units Index FIGURE 6-3.
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MODEL XMT-P pH/ORP UPDATE_EVT: Time Stamp UPDATE_EVT: Static Rev UPDATE_EVT: Relative Index BLOCK_ALM: Unacknowledged BLOCK_ALM: Alarm State BLOCK_ALM: Time Stamp BLOCK_ALM: Subcode BLOCK_ALM: Value ALARM_SUM: Current ALARM_SUM: Unacknowledged ALARM_SUM: Unreported ALARM_SUM: Disabled ACK_OPTION HI_HI_ALM: Unacknowledged HI_HI_ALM: Alarm State HI_HI_ALM: Time Stamp HI_HI_ALM: Subcode HI_HI_ALM: Float Value HI_ALM: Unacknowledged HI_ALM: Alarm State HI_ALM: Time Stamp HI_ALM: Subcode HI_ALM: Float Value LO_
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MODEL XMT-P pH/ORP SECTION 6.0 OPERATION WITH MODEL 375 PV: Value FIGURE 6-3.
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MODEL XMT-P pH/ORP UPDATE_EVT: Relative Index BLOCK_ALM: Unacknowledged BLOCK_ALM: Alarm State BLOCK_ALM: Time Stamp BLOCK_ALM: Sub Code BLOCK_ALM: Value ALARM_SUM: Current ALARM_SUM: Unacknowledged ALARM_SUM: Unreported ALARM_SUM: Disabled ACK_OPTION ALARM_HYS HI_HI_PRI HI_HI_LIM HI_PRI HI_LIM LO_PRI LO_LIM LO_LO_PRI LO_LO_LIM DV_HI_PRI DV_HI_LIM DV_LO_PRI DV_LO_LIM HI_HI_ALM: Unacknowledged HI_HI_ALM: Alarm State HI_HI_ALM: Time Stamp HI_HI_ALM: Subcode HI_HI_ALM: Float Value HI_ALM: Unacknowledged HI_AL
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MODEL XMT-P pH/ORP SECTION 6.0 OPERATION WITH MODEL 375 Scheduling FIGURE 6-3.
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MODEL XMT-P pH/ORP Normal Rcv Urgent Rcv Time Available SAP EC DC Normal SAP EC DC Urgent SAP EC DC Time Available Rcv SAP EC DC Normal Rcv SAP EC DC Urgent Rcv SAP EC DC Queue Overflow Statistics 2 Time Available SAP SM Time Available Rcv SAP SM Normal SAP Las Normal Rcv SAP Las Time Available SAP Src Sink Normal SAP Src Sink Urgent SAP Src Sink Time Available Rcv SAP Src Sink Normal Rcv SAP Src Sink Urgent Rcv SAP Src Sink Sys Q Link Master Parameters DImeLinkMasterCapabilitiesVariable PrimaryLinkMasterF
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MODEL XMT-P pH/ORP SECTION 7.0 PROGRAMMING THE TRANSMITTER SECTION 7.0 PROGRAMMING THE TRANSMITTER 7.1 GENERAL This section describes how to program the transmitter using the keypad. 1. Configure and assign values to the 4-20 mA output (-HT version only). 2. Test and trim the current output (-HT version only). 3. Select the measurement to be made (pH, ORP, or Redox). 4. Choose temperature units and automatic or manual temperature mode. 5. Set a security code. 6.
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MODEL XMT-P pH/ORP SECTION 7.0 PROGRAMMING THE TRANSMITTER 7.3 CONFIGURING AND RANGING THE OUTPUT (-HT version only) 7.3.1 Purpose 1. Configuring an output means a. displaying the output reading in units of mA or percent of full scale. b. changing the time constant for output dampening. c. assigning the value the output current will take if the transmitter detects a fault in itself or the sensor. 2. Ranging the output means assigning values to the 4 mA and 20 mA outputs. 3.
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MODEL XMT-P pH/ORP SECTION 7.0 PROGRAMMING THE TRANSMITTER 7.3.3 Procedure: Configuring the Output Calibrate Program Output Measurement° Output? Configure Configure? mA/% Hold Display Temp Test Fault 5. Choose Fixed or Live. Live 6. If you chose Fixed, the screen at left appears. Use the arrow keys to change the fault current to the desired value. The limits are 4.00 to 22.00 mA. If you chose Live, there are no settings to make. Fault Configure? 7. The screen at left appears. Choose mA/%.
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MODEL XMT-P pH/ORP SECTION 7.0 PROGRAMMING THE TRANSMITTER 7.3.5 Procedure: Testing the output Calibrate Program Output Measurement° Output? Configure Hold 1. Press MENU. The menu screen appears. Choose Program. Display Temp 2. Choose Output. >> Test 3. Choose Test. Range 4. Choose Test Output. Test Output Trim Output 5. Use the arrow keys to change the displayed current to the desired value. Press ENTER. The output will change to the value just entered. Current Output for Test:12.00mA 6.
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MODEL XMT-P pH/ORP SECTION 7.0 PROGRAMMING THE TRANSMITTER 7.4 CHOOSING AND CONFIGURING THE ANALYTICAL MEASUREMENT 7.4.1 Purpose This section describes how to do the following: 1. Configure the transmitter to measure pH, ORP, or Redox. 2. Determine the location of the preamp. 3. If pH was selected, there are additional selections and settings to make: a. choose a solution temperature correction curve or set a temperature coefficient constant b. choose sensor isopotential c.
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MODEL XMT-P pH/ORP SECTION 7.0 PROGRAMMING THE TRANSMITTER 7.4.3 Procedure: Measurement. To choose a menu item, move the cursor to the item and press ENTER. To store a number or setting, press ENTER. Calibrate Hold Program Display Outputs Temp Measurement >> Measure? pH Redox ORP 1. Press MENU. The main menu screen appears. Choose Program. 2. Choose Measurement. 3. Choose pH, Redox, or ORP. If you chose pH, do steps 5 through 9. If you chose ORP or Redox, do step 10.
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MODEL XMT-P pH/ORP SECTION 7.0 PROGRAMMING THE TRANSMITTER 7.5 CHOOSING TEMPERATURE UNITS AND MANUAL OR AUTOMATIC TEMPERATURE COMPENSATION 7.5.1 Purpose This section describes how to do the following: 1. Choose temperature display units (°C or °F). 2. Choose automatic or manual temperature compensation. 3. Enter a temperature for manual temperature compensation 7.5.2 Definitions 1. AUTOMATIC TEMPERATURE COMPENSATION. The analyzer uses a temperature-dependent factor to convert measured cell voltage to pH.
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MODEL XMT-P pH/ORP SECTION 7.0 PROGRAMMING THE TRANSMITTER 7.6 SETTING A SECURITY CODE 7.6.1 Purpose This section describes how to set a security code. There are three levels of security: a. A user can view the default display and information screens only. b. A user has access to the calibration and hold menus only. c. A user has access to all menus. The security code is a three-digit number. The table shows what happens when security codes are assigned to Calib (calibration) and Config (configure).
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MODEL XMT-P pH/ORP SECTION 7.0 PROGRAMMING THE TRANSMITTER 7.7 MAKING HART RELATED SETTINGS For more information refer to Section 6.0. 7.8 NOISE REDUCTION 7.8.1 Purpose For maximum noise reduction, the frequency of the ambient AC power must be entered. 7.8.2 Procedure: Noise reduction Calibrate Hold Program Display Outputs Temp Measurement 1. Press MENU. The menu screen appears. Choose Program. 2. Choose >>. >> Security HART 3. Choose >>. >> 4. Choose Noise Rejection.
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MODEL XMT-P pH/ORP SECTION 7.0 PROGRAMMING THE TRANSMITTER 7.10 SELECTING A DEFAULT SCREEN AND SCREEN CONTRAST 7.10.1 Purpose This section describes how to do the following: 1. Set a default screen. The default screen is the screen shown during normal operation. The Solu Comp Xmt allows the user to choose from a number of screens. Which screens are available depends on the measurement the transmitter is making. 2. Change the screen contrast. 7.10.2 Procedure: Choosing a display screen.
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MODEL XMT-P pH/ORP SECTION 8.0 CALIBRATION — TEMPERATURE SECTION 8.0 CALIBRATION — TEMPERATURE 8.1 INTRODUCTION The Calibrate Menu allows the user to calibrate the pH, ORP (or redox), and temperature response of the sensor. 8.2 CALIBRATING TEMPERATURE 8.2.1 Purpose Temperature affects the measurement of pH in three ways. 1. The analyzer uses a temperature dependent factor to convert measured cell voltage to pH.
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MODEL XMT-P pH/ORP SECTION 8.0 CALIBRATION — TEMPERATURE 8.2.2 Procedure 1. Remove the sensor from the process. Place it in an insulated container of water along with a calibrated thermometer. Submerge at least the bottom two inches of the sensor. Stir continuously. 2. Allow the sensor to reach thermal equilibrium. For some sensors, the time constant for a change in temperature is 5 min., so it may take as long as 30 min. for temperature equilibration. 3.
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MODEL XMT-P pH/ORP SECTION 9.0 CALIBRATION — pH SECTION 9.0 CALIBRATION — pH 9.1 INTRODUCTION For pH sensors, two-point buffer calibration is standard. Both automatic calibration and manual calibration are available. Auto calibration avoids common pitfalls and reduces errors. Its use is recommended. In auto calibration the Solu Comp Xmt calculates the actual pH of the buffer from the nominal value entered by the user and does not accept calibration data until readings are stable.
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MODEL XMT-P pH/ORP SECTION 9.0 CALIBRATION — pH 9.2 PROCEDURE — AUTO CALIBRATION 1. Obtain two buffer solutions. Ideally, the buffer values should bracket the range of pH values to be measured. 2. Remove the pH sensor from the process liquid. If the process and buffer temperatures are appreciably different, place the sensor in a container of tap water at the buffer temperature. Do not start the calibration until the sensor has reached the buffer temperature. Thirty minutes is usually adequate.
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MODEL XMT-P pH/ORP SECTION 9.0 CALIBRATION — pH Live 10.01pH AutoBuf2 10.01pH Cal in progess. 14. The top line shows the actual reading. The transmitter also identifies the buffer and displays the nominal buffer value (buffer pH at 25°C). If the displayed value is not correct, press é or ê to display the correct value. The nominal value will change, for example from 9.91 to 10.02 pH. Press ENTER to store. 15. The screen at the left appears momentarily. Please wait. Offset 0mV 59.
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MODEL XMT-P pH/ORP SECTION 9.0 CALIBRATION — pH 9.3 PROCEDURE — MANUAL TWO-POINT CALIBRATION 1. Obtain two buffer solutions. Ideally, the buffer values should bracket the range of pH values to be measured. 2. Remove the pH sensor from the process liquid. If the process and buffer temperatures are appreciably different, place the sensor in a container of tap water at the buffer temperature. Do not start the calibration until the sensor has reached the buffer temperature. Thirty minutes is usually adequate.
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MODEL XMT-P pH/ORP SECTION 9.0 CALIBRATION — pH 9.4 PROCEDURE — STANDARDIZATION 1. The pH measured by the transmitter can be changed to match the reading from a second or referee instrument. The process of making the two readings agree is called standardization. 2. During standardization, the difference between the two values is converted to the equivalent voltage. The voltage, called the reference offset, is added to all subsequent measured cell voltages before they are converted to pH.
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MODEL XMT-P pH/ORP SECTION 9.0 CALIBRATION — pH 9.5 PROCEDURE — ENTERING A KNOWN SLOPE VALUE. 1. If the electrode slope is known from other measurements, it can be entered directly into the transmitter. The slope must be entered as the slope at 25°C. To calculate the slope at 25°C from the slope at temperature t°C, use the equation: slope at 25°C = (slope at t°C) 298 t°C + 273 Changing the slope overrides the slope determined from the previous buffer calibration.
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MODEL XMT-P pH/ORP SECTION 9.0 CALIBRATION — pH 9.6 ORP CALIBRATION 9.6.1 Purpose 1. For process control, it is often important to make the measured ORP agree with the ORP of a standard solution. 2. During calibration, the measured ORP is made equal to the ORP of a standard solution at a single point. 9.6.2 Preparation of ORP standard solutions ASTM D1498-93 gives procedures for the preparation of iron (II) - iron (III) and quinhydrone ORP standards. The iron (II) - iron (III) standard is recommended.
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MODEL Xmt-P SECTION 10.0 TROUBLESHOOTING SECTION 10.0 TROUBLESHOOTING 10.1 OVERVIEW The Xmt-P transmitter continuously monitors itself and the sensor for problems. If the transmitter detects a problem, the word "fault" or "warn" appears in the main display alternating with the measurement. A fault condition means the measurement is seriously in error and is not to be trusted. A fault condition might also mean that the transmitter has failed. Fault conditions must be corrected immediately.
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MODEL Xmt-P SECTION 10.0 TROUBLESHOOTING 10.2 TROUBLESHOOTING WHEN A FAULT OR WARNING MESSAGE IS SHOWING Fault message Explanation See Section RTD Open RTD measuring circuit is open 10.2.1 RTD Ω Overrange RTD resistance is outside the range for Pt 100 or 22k NTC 10.2.1 Broken Glass pH sensing element in pH sensor is broken 10.2.2 Glass Z Too High pH glass impedance exceeds programmed level 10.2.2 ADC Read Error Analog to digital converter failed 10.2.
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MODEL Xmt-P SECTION 10.0 TROUBLESHOOTING 10.2.2 Broken pH Glass and pH Glass Z High These messages mean that the pH sensor glass impedance is outside the programmed limits. To read the impedance go to the main display and press ê until Glass Imp appears in the display. The default lower limit is 10 MΩ. The default upper limit is 1000 MΩ. Low glass impedance means the glass membrane — the sensing element in a pH sensor — is cracked or broken.
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MODEL Xmt-P SECTION 10.0 TROUBLESHOOTING 10.2.8 pH mV Too High This message means the raw millivolt signal from the sensor is outside the range -2100 to 2100 mV. 1. Verify all wiring connections, including connections in a junction box. 2. Check that the pH sensor is completely submerged in the process liquid. 3. Check the pH sensor for cleanliness. If the sensor look fouled of dirty, clean it. Refer to the sensor instruction manual for cleaning procedures. 10.2.
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MODEL Xmt-P SECTION 10.0 TROUBLESHOOTING 10.3 TROUBLESHOOTING WHEN NO FAULT MESSAGE IS SHOWING - TEMPERATURE 10.3.1 Temperature measured by standard was more than 1°C different from controller. A. Is the standard thermometer, RTD, or thermistor accurate? General purpose liquid-in-glass thermometers, particularly ones that have been mistreated, can have surprisingly large errors. B. Is the temperature element in the sensor completely submerged in the liquid? C.
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MODEL Xmt-P SECTION 10.0 TROUBLESHOOTING 10.5.1 Warning or error message during two-point calibration. Once the two-point (manual or automatic) calibration is complete, the transmitter automatically calculates the sensor slope (at 25°C). If the slope is less than 45 mV/pH, the transmitter displays a "Slope error low" message. If the slope is greater than 60 mV/pH, the transmitter displays a "Slope error high" message. The transmitter will not update the calibration. Check the following: A.
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MODEL Xmt-P SECTION 10.0 TROUBLESHOOTING D. Is the sensor fouled? The sensor measures the pH of the liquid adjacent to the glass bulb. If the sensor is heavily fouled, the pH of liquid trapped against the bulb may be different from the bulk liquid. E. Has the sensor been exposed to poisoning agents (sulfides or cyanides) or has it been exposed to extreme temperature? Poisoning agents and high temperature can shift the reference voltage many hundred millivolts. 10.5.
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MODEL Xmt-P SECTION 10.0 TROUBLESHOOTING or terminals. 4. Connect a jumper wire between the RTD RETURN and RTD SENSE terminals (see wiring diagrams in Section 3.0). 5. If noise and/or offsets disappear, the interference was coming into the analyzer through one of the sensor wires. The system can be operated permanently with the simplified wiring. D. Check for extra ground connections or induced noise. 1. If the sensor cable is run inside conduit, there may be a short between the cable and the conduit.
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MODEL Xmt-P SECTION 10.0 TROUBLESHOOTING 10.7.3 Simulating pH input when the preamplifier is in a junction box. The procedure is the same as described in Section 10.7.2. Keep the connections between the analyzer and the junction box in place. Disconnect the sensor at the sensor side of the junction box and connect the voltage source to the sensor side of the junction box. See Figure 10-3. 10.7.4 Simulating pH input when the preamplifier is in the sensor.
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MODEL Xmt-P SECTION 10.0 TROUBLESHOOTING 10.9 MEASURING REFERENCE VOLTAGE Some processes contain substances that poison or shift the potential of the reference electrode. Sulfide is a good example. Prolonged exposure to sulfide converts the reference electrode from a silver/silver chloride electrode to a silver/silver sulfide electrode. The change in reference voltage is several hundred millivolts.
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MODEL Xmt-P SECTION 11.0 MAINTENANCE SECTION 11.0 MAINTENANCE 11.1 OVERVIEW The Solu Comp Xmt needs little routine maintenance. The calibration of the analyzer and sensor should be checked periodically. To recalibrate the sensor and analyzer, refer to sections 9 through 14. 11.2 REPLACEMENT PARTS Only a few components of the analyzer are replaceable. Refer to the tables below. Circuit boards, display, and enclosure are not replaceable. TABLE 11-1.
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MODEL XMT-P pH/ORP SECTION 12.0 pH MEASUREMENTS SECTION 12.0 pH MEASUREMENTS 12.1 12.2 12.3 12.4 12.5 12.6 12.7 12.8 12.9 12.10 12.11 General Measuring Electrode Reference Electrode Liquid Junction Potential Converting Voltage to pH Glass Electrode Slope Buffers and Calibration Isopotential pH Junction Potential Mismatch Sensor Diagnostics Shields, Insulation, and Preamplifiers 12.
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MODEL XMT-P pH/ORP designed, the liquid junction potential is usually small and relatively constant. All three potentials depend on temperature. As discussed in Sections 12.5 and 12.6, the factor relating the cell voltage to pH is also a function of temperature. The construction of each electrode and the electrical potentials associated with it are discussed in Sections 12.2, 12.3, and 12.4. 12.2 MEASURING ELECTRODE SECTION 12.
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MODEL XMT-P pH/ORP 12.4 LIQUID JUNCTION POTENTIAL The salt bridge (see Figure 12-4) is an integral part of the reference electrode. It provides the electrical connection between the reference electrode and the liquid being measured. Salt bridges take a variety of forms, anything from a glass frit to a wooden plug. Salt bridges are highly porous, and the pores are filled with ions. The ions come from the filling solution and the sample. Some bridges permit only diffusion of ions through the junction.
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MODEL XMT-P pH/ORP The second term, 0.1984 T pH, is the potential (in mV) at the outside surface of the pH glass. This potential depends on temperature and on the pH of the sample. Assuming temperature remains constant, any change in cell voltage is caused solely by a change in the pH of the sample. Therefore, the cell voltage is a measure of the sample pH. Note that a graph of equation 1, E(T) plotted against pH, is a straight line having a y-intercept of E°(T) and a slope of 0.1984 T. SECTION 12.
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MODEL XMT-P pH/ORP SECTION 12.0 pH MEASUREMENTS are placed in pH 10 buffer, the cell voltage is V10. Note that V7 is not 0 mV as would be expected in an ideal sensor, but is slightly different. The microprocessor calculates the equation of the straight line connecting the points. The general form of the equation is: E = A + B (t + 273.15) (pH - 7) (2) The slope of the line is B (t + 273.15), where t is the temperature in °C, and the y-intercept is A. If pH 7 buffer is used for calibration, V7 equals A.
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MODEL XMT-P pH/ORP term in equation 4 to the voltage is also shown. The liquid junction potentials in the buffers are assumed to be equal and are exaggerated for clarity. If the liquid junction potential in the sample differs from the buffers, a measurement error results. Figure 12-8 illustrates how the error comes about. Assume the true pH of the sample is pHs and the cell voltage is Es. The point (pHs, Es) is shown on the graph.
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MODEL XMT-P pH/ORP SECTION 13.0 ORP MEASUREMENTS SECTION 13.0 ORP MEASUREMENTS 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 General Measuring Electrode Reference Electrode Liquid Junction Potential Relating Cell Voltage to ORP ORP, Concentration, and pH Interpreting ORP Measurements Calibration 13.1 GENERAL Figure 13-1 shows a simplified diagram of an electrochemical cell that can be used to determine the oxidationreduction potential or ORP of a sample.
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MODEL XMT-P pH/ORP SECTION 13.0 ORP MEASUREMENTS 13.2 MEASURING ELECTRODE 13.4 LIQUID JUNCTION POTENTIAL Figure 13-2 shows a typical ORP measuring electrode. The electrode consists of a band or disc of platinum attached to the base of a sealed glass tube. A platinum wire welded to the band connects it to the lead wire. A salt bridge (see Figure 13-3) is an integral part of the reference electrode. It provides the electrical connection between the reference electrode and the liquid being measured.
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MODEL XMT-P pH/ORP SECTION 13.0 ORP MEASUREMENTS FIGURE 13-4. The Origin of Liquid Junction Potentials. The figure shows a thin section through a pore in the junction plug. The junction separates a solution of potassium chloride on the left from a solution of hydrochloric acid on the right. The solutions have equal molar concentration. Driven by concentration differences, hydrogen ions and potassium ions diffuse in the directions shown. The length of each arrow indicates relative rates.
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MODEL XMT-P pH/ORP SECTION 13.0 ORP MEASUREMENTS is described by the following equation, called the Nernst equation: 0.1987 (t + 273.15) log [Fe+2] n [Fe+3] (2) ORP, mV In the Nernst equation, E is the electrode potential and E° is the standard electrode potential, both in millivolts, t is temperature in °C, n is the number of electrons transferred (n = 1 in the present case), and [Fe+2] and [Fe+3] are the concentrations of iron (II) and iron (III) respectively.
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MODEL XMT-P pH/ORP SECTION 13.0 ORP MEASUREMENTS chlorine. Although the details are beyond the scope of this discussion, the result is shown in equation 7: The Nernst equation for reaction 3 is: E = E°- 0.1987 (t + 273.15) log 6 [Cr+3] 2 [Cr2O7-2] [H+]14 (4) E = E° - Note that the hydrogen ion factor in the concentration ratio is raised to the fourteenth power. The table shows the expected effect of changing pH on the measured ORP at 25°C. pH changes ORP changes by from 2.0 to 2.2 7 mV from 2.
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MODEL XMT-P pH/ORP SECTION 13.0 ORP MEASUREMENTS The ORP of the iron (II) - iron (III) standard when measured with a platinum electrode against a saturated silver-silver chloride reference is 476 ± 20 mV at 25°C. The range of values is caused primarily by the high and variable liquid junction potential generated in solutions containing high acid concentrations. Quinhydrone - hydroquinone ORP standards are also used. They are prepared by dissolving excess quinhydrone in either pH 4.00 or pH 6.86 buffer.
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MODEL XMT-P PH/ORP SECTION 14.0 THEORY - REMOTE COMMUNICATIONS SECTION 14.0 THEORY - REMOTE COMMUNICATIONS 14.1 14.2 14.3 Overview of HART Communications HART Interface Devices AMS Communication 14.1 OVERVIEW OF HART COMMUNICATION HART (highway addressable remote transducer) is a digital communication system in which two frequencies are superimposed on the 4 to 20 mA output signal from the transmitter. A 1200 Hz sine wave represents the digit 1, and a 2400 Hz sine wave represents the digit 0.
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MODEL XMT-P PH/ORP SECTION 14.0 THEORY - REMOTE COMMUNICATIONS If your communicator does not recognize the Model XMT-P pH/ORP transmitter, the device description library may need updating. Call the manufacturer of your HART communication device for updates. 14.3 ASSET MANAGEMENT SOLUTIONS Asset Management Solutions (AMS) is software that helps plant personnel better monitor the performance of analytical instruments, pressure and temperature transmitters, and control valves.
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MODEL XMT-P pH/ORP SECTION 15.0 RETURN OF MATERIAL SECTION 15.0 RETURN OF MATERIAL 15.1 GENERAL. 15.3 NON-WARRANTY REPAIR. To expedite the repair and return of instruments, proper communication between the customer and the factory is important. Call 1-949-757-8500 for a R e t u r n Materials Authorization (RMA) number. The following is the procedure for returning for repair instruments that are no longer under warranty: 1. Call Rosemount Analytical for authorization. 2.
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WARRANTY Goods and part(s) (excluding consumables) manufactured by Seller are warranted to be free from defects in workmanship and material under normal use and service for a period of twelve (12) months from the date of shipment by Seller. Consumables, pH electrodes, membranes, liquid junctions, electrolyte, O-rings, etc. are warranted to be free from defects in workmanship and material under normal use and service for a period of ninety (90) days from date of shipment by Seller.
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The right people, the right answers, right now. ON-LINE ORDERING NOW AVAILABLE ON OUR WEB SITE http://www.raihome.com Specifications subject to change without notice. Credit Cards for U.S. Purchases Only. Emerson Process Management 2400 Barranca Parkway Irvine, CA 92606 USA Tel: (949) 757-8500 Fax: (949) 474-7250 http://www.raihome.com © Rosemount Analytical Inc.