8.0 TROUBLESHOOTING GUIDE
Symptom | Possible Causes | Suggested Actions |
The LCD does not display. | No power to the instrument. | Check power supply to be |
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| sure the correct voltage is |
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| being supplied to the |
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| transmitter. (13.5 to 50 |
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| VDC) |
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| Check polarity of transmitter |
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| wiring. |
| Contrast level is set too low. | Set contrast level to a higher |
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| value. Because the contrast |
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| menu is always the top |
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| menu, it can be reached by |
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| pressing the upper MENU |
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| SELECTION key at least 12 |
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| times. Enter the calibrate |
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| mode and increase the |
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| value. |
| Sensor or signal conditioner | Check the sensor for proper |
| has a short that draws too | operation. To verify, |
| much power from the | disconnect all sensor wires |
| transmitter. | and cycle power off, then on. |
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The pH fluctuates from | The slope calibration is mis- | Check buffers to make sure |
minimum scale to | calibrated. Typically the | they are the correct values. |
or the pH is locked at high or | transmitter is calibrated with |
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low scale. | no slope (0 mV/pH). | Use the |
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| calibration feature on the |
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| Electrode Span Menu, then |
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| perform a buffer calibration. |
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| Check the electrode and |
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| sensor for proper operation. |
| Wrong temperature | Examine the temperature |
| correction has been | and the Temperature |
| calibrated in the temperature | Calibration Menu. Adjust trim |
| trim. | as required. |
The pH or ORP reading short | The transmitter may have | Check buffers to make sure |
spans. | been | they are the correct values. |
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| Use the |
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| calibration feature on the |
Model
