Instruction Manual pH 500 LCD Transmitter pH/ORP Transmitter with Display 68X216829 Rev 2 05/04 Technology Made Easy ... Preface This manual serves to explain the use of the pH 500 transmitter. It functions in two ways, firstly as a step by step guide to help you to operate the transmitter. Secondly, it serves as a handy reference guide. It is written to cover as many anticipated applications of the transmitter as possible. If there are doubts in the use of the transmitter, please do not hesitate to contact the nearest Authorized Distributor. Eutech Instruments / Oakton Instruments will not accept any responsibility for damage or malfunction to the transmitter caused by improper use of the instrument. Remember to fill in the guarantee card and mail it back to your authorized distributor. The information presented in this manual is subject to change without notice as improvements are made, and does not represent a commitment on the part of Eutech Instruments / Oakton Instruments. Copyright © 2002 All rights reserved Eutech Instruments / Oakton Instruments Rev 2 05/04 TABLE OF CONTENTS 1 2 2.1 2.2 INTRODUCTION PREPARATION Power Supply Requirements (SL2 Position) 3 Connecting the Electrode and Temperature Probe (SL1 Position) 1 2 3 3 3.1 3.2 INSTALLATION Wall Mount Panel Mount 5 6 5 4 4.1 4.2 DISPLAY AND KEYPAD FUNCTIONS Display Keypad 7 8 7 5 5.1 5.2 5.3 5.4 CALIBRATION Preparing the Transmitter for Calibration pH Calibration Relative mV Calibration Temperature Calibration 9 10 11 11 9 6 6.1 6.2 6.3 6.4 6.5 6.6 ADVANCED SETUP FUNCTIONS Offset Setting (Unavailable in ORP mode) 12 Output Range Setting 13 Temperature Compensation Setting (Unavailable in ORP mode) HOLD Current Setting 17 Out-of-Range Current Setting 17 Configuration 18 12 14 7 8 9 10 11 12 13 PROBE CARE AND MAINTENANCE TROUBLE SHOOTING GUIDE SPECIFICATIONS TECHNICAL DIMENSIONS ACCESSORIES WARRANTY RETURN OF ITEMS 20 22 23 24 25 27 27 Instruction Manual pH 500 1 INTRODUCTION Thank you for selecting a pH 500 pH/ORP Transmitter. This transmitter is a microprocessor-based instrument that is designed to be sturdy and user-friendly. It is capable of measuring pH, mV and temperature. This transmitter has many user-friendly features ­ all of which are completely accessible through the water-resistant membrane keypad. Your transmitter includes an instruction manual and a warranty card. Please read this manual thoroughly before operating your transmitter. MEAS READY . . pH °C ATC -1- Instruction Manual pH 500 2 PREPARATION Remove screws from the four corners at the back of the Transmitter, and remove back cover. Connectors should be exposed as follows: Figure 1 ­ Connection Guide All wiring is done on 2 detachable connectors: ­ 1. 2. 9-pin connector (located on SL1 position) for pH electrode, temperature sensor and potential matching pin (PMP); & 3-pin connector (located on SL2 position) for power supply. Using a suitable screwdriver, loosen screws from top of connector. When inserting the wires, always hold connector with top screws facing up. -2- Instruction Manual pH 500 2.1 Power Supply Requirements (SL2 Position) This transmitter requires a 12 to 24V DC power supply. Other Transmitters and/or a chart recorder may be connected in series. 1. 2. Insert positive loop wire from power supply to pin 1, tighten screw. Insert negative loop wire to pin 2, tighten screw. This wire may be linked to a chart recorder or to negative terminal of power supply. 1 Alpha pH500 2 Power Supply Chart recorder 2.2 Connecting the Electrode and Temperature Probe (SL1 Position) To connect the pH or ORP electrode: pH reference Clear sheath 2.2.1 The pH transmitter accepts any combination electrode for pH or ORP measurements 1. pH sensing Insulation Screen Remove BNC connector from cable. Two wires will be exposed. 2. Strip insulation, just enough to expose bare wires. IMPORTANT: For pH/ORP sensing cable, remember to strip the inner black layer (screen) and expose the clear plastic sheath. 1. 2. Insert pH sensing cable into pin 1 of connector. Tighten screw. Insert pH reference cable into pin 2 of connector. Tighten screw. NOTE: Instead of removing the BNC connection, Oakton offers an optional adapter (part number 05994-90 BNC to Spade Lug adapter) that can be used. -3- Instruction Manual pH 500 2.2.2 To connect temperature probe: For Automatic Temperature Compensated (ATC) pH readings, a 100 Pt RTD temperature probes can be used. Industrial pH electrodes are often offered with ATC, which will typically be bare wires. 3-wire probe 1. 2. 3. 1. 2. Insert Pt 100 sense wire to pin 5 of connector. Tighten screw. Insert Pt 100 input wire to pin 6 of connector. Tighten screw. Insert Pt 100 return wire to pin 7 of connector. Tighten screw. Take a small length of wire and short pins 5 and 6 of connector. Insert Pt 100 sense wire into pin 6 of connector and tighten screws. Insert Pt 100 return wire to pin 7 of connector. Tighten screw. 2-wire probe: IMPORTANT: Temperature probe should always be together with pH probe, even during calibration. Make sure no bare wires are exposed and all screws are tightened for proper contact. 2.2.3 To connect Potential Matching Pin (Liquid electrical interferences): Connect the additional wire from the electrode to pin 8. Transmitter must be configured to `Symmetrical mode of operation' - Please refer to `Advanced Setup Functions', Section 6.6.2 ­ Selecting Asymmetrical or Symmetrical Mode of Operation. -4- Instruction Manual pH 500 3 INSTALLATION 3.1 Wall Mount -5- Instruction Manual pH 500 3.2 Panel Mount 1. Prepare panel cut-out of 92.0 mm by 92.0 mm Panel (side) 2. Remove back cover of transmitter and slide it through panel cut-out 4. Thread rods through lugs until transmitter is held in place against panel 3. Attach lugs to either side of transmitter -6- Instruction Manual pH 500 4 DISPLAY AND KEYPAD FUNCTIONS 4.1 Display The LCD has a primary and secondary display. · The primary display shows the measured pH, mV or Relative mV value. · The secondary display shows the measured temperature. In Calibration mode, pH buffer values are displayed here; while measured mV values are displayed in the ORP Calibration mode. 1 2 3 SETUP 15 14 READY HOLD MEAS CAL -. . . 888 ERR mV pH 4 5 6 7 8 9 13 -. . . 1888 10 6. Primary display 7. Temperature indicator °C ATC pH 12 1. SETup mode indicator 11 11. ERRor indicator 12. Probe indicator 13. Buffer indicator 14. HOLD indicator 15. READY indicator 2. MEASurement mode indicator 3. CALibration indicator 4. mV indicator 5. pH indicator 8. pH buffer selection indicator 9. Automatic Temperature Compensation indicator 10. Secondary display -7- Instruction Manual pH 500 4.2 Keypad The four-button keypad allows easy and quick operations of the Transmitter. Key CAL Function Brings you directly into the Calibration mode. If you were in pH Measurement mode, press CAL to enter pH Calibration mode. If you were in mV Measurement mode, press CAL to enter mV Calibration mode. / To scroll through the various submenus To increment/decrement values or toggle between options (in the SETUP/CAL modes) When pressed together, serves as escape function to return to MEAS mode from any point (CAL or SETUP modes). ENT To confirm your calibration values in Calibration mode. To confirm selections in SETUP mode. While in MEAS mode, pressing ENT takes you directly to SETUP submenu -8- Instruction Manual pH 500 5 CALIBRATION 5.1 Preparing the Transmitter for Calibration Before starting calibration, make sure you are in the correct measurement mode. When you switch on the transmitter, the transmitter starts up in the units last used. For example, if you shut the transmitter off in "mV" units, the transmitter will read "mV" units when you switch the transmitter on. Be sure to remove the protective electrode storage bottle or rubber cap of the electrode before calibration or measurement. If the electrode has been stored dry, wet the electrode in tap water for 10 minutes before calibrating or taking readings to saturate the pH electrode surface and minimize drift. Wash your electrode in deionized water after use, and store in electrode storage solution. If storage solution is not available, use pH 4.01 or 7.00 buffer solution. Do not reuse buffer solutions after calibration. Contaminants in the solution can affect the calibration, and eventually the accuracy of the measurements. The transmitter features two internationally recognized buffer standards. Select the buffer standard you require in the CAL mode Select from the following buffer options: · · First-point: pH 7.00 (USA buffer) or pH 6.86 (NIST buffer). Second point: pH 4.01, 9.18, or 10.1. NOTE: When transmitter is entered into the CAL mode, the 4/20 mA output current will be automatically held. `HOLD' will be displayed on LCD. After Calibration and transmitter is returned to MEAS mode, the `HOLD' is automatically released. Please refer to page 17, section 6.4 for more details. -9- Instruction Manual pH 500 5.2 pH Calibration A complete 2-point CAL is required for this Transmitter. If Calibration is aborted after 1st calibration point, transmitter reverts to previous Calibration data. 1. CAL READY HOLD . . CAL pH Rinse probe thoroughly with de-ionized water or a rinse solution. Blot excess liquid. Dip probe into calibration buffer. End of probe must be completely immersed into buffer. Stir probe gently to create a homogeneous sample. From pH MEAS mode, press CAL to enter pH calibration mode. CAL indicator will be shown. Primary display will show measured reading while secondary display will indicate the pH standard buffer solution. 2. pH 3. READY HOLD . . pH pH 4. Press or keys to select either pH 7.00 (USA) or pH 6.86 (NIST) standard buffers. This is the first point, Offset calibration. 5. Wait for measured pH value to stabilize. Press ENTER to confirm calibration. Transmitter is now calibrated to current buffer. Rinse probe with de-ionized water or rinse solution, and place in next pH buffer (pH 4.01, pH 9.18 or pH 10.01). Repeat steps 5 and 6. Upon successful Calibration, transmitter displays Slope (primary display, in mV) and Offset (secondary display, in pH) of electrode. Press ENTER to return to MEAS mode. Transmitter has been calibrated. Rinse electrode and proceed with measurements. CAL HOLD CAL READY HOLD 6. . . pH pH 7. 8. mV 9. . . pH NOTES: To exit from pH calibration mode without confirming calibration, press and keys together. If selected buffer value is not within ±1.0 pH from measured pH value: electrode and buffer icon blink and ERR annunciator appears in lower left corner of display. - 10 - Instruction Manual pH 500 5.3 1. Relative mV Calibration From the ORP MEAS mode, press CAL key. CAL indicator appears at top of LCD. Primary display shows relative mV reading and secondary display shows absolute mV value. NOTE: If you have never calibrated relative mV or if the transmitter has been reset, the value shown in the primary display is the same as the absolute mV value. Press or keys to enter the relative mV value that matches your desired reading (only the readings in the primary display changes). Press ENTER key to confirm. Transmitter will now display the offset in the readings. Press ENTER key to return to MEAS mode. READY HOLD CAL READY HOLD R.mV 2. CAL READY HOLD R.mV 3. 4. 5. CAL R.mV 5.4 Temperature Calibration Temperature calibration is available only in the pH measurement mode and when ATC probe is available. Calibrate temperature probe only if temperature value displayed on transmitter is different from that of a calibrated thermometer. Please refer to section 6.3.1 for further information. - 11 - Instruction Manual pH 500 6 ADVANCED SETUP FUNCTIONS The advanced setup mode lets you customize your transmitter's preferences and defaults. This transmitter features different sub groups that organize all setup parameters. The sub-groups are: 6.1 Offset Setting (Unavailable in ORP mode) As a result of the continuous measurement and the application concerned, it may not be convenient to remove the electrode for calibration. In such cases, an on-line Offset adjustment is offered. SETUP HOLD 1. Press ENT key. Transmitter displays `OFS'. Press ENT again. Upper display shows amount of offset, in terms of pH; lower display shows current measured pH value. Use or keys to introduce offset to pH readings. As the lower measured reading changes, upper display records the amount of offset. Maximum of ± 2.00 pH offset is allowed. Press both or keys together to return to ` MEAS ` mode. 2. SETUP READY HOLD . . pH pH 3. - 12 - Instruction Manual pH 500 6.2 Output Range Setting SETUP HOLD Output of pH 500 transmitter is via the 2-wire power supply loop. Both the 4 mA and 20 mA output can be assigned to specific pH or ORP values, fo ...