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| PROBLEM |
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POSSIBLE CAUSE |
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SOLUTION |
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| Calibration failure. |
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Weak ammonia buffer. |
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Replace ammonia buffer. Ammonia should be replaced at least bi-monthly. Discard old ammonia, do not top off. |
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| Calibration failure. |
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Standard solutions not flowing. |
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Check that solenoid valve is actuating during calibration. Make sure standard bottle cap is loosened so a vacuum is not preventing flow. Remove connector from the calibration tube and blow into tube during calibration to ensure there is no blockage. Place standard bottle at highest possible point above analyzer to ensure maximum fall. |
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| Calibration failure. |
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Contaminated or incorrect standard. |
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Replace standard with known value. Recommended standard is 100ppb. Analyzer will not allow a calibration to be attempted below 20ppb. |
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| Calibration failure. |
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Incorrect standards value input on analyzer. |
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Check that button labeled “STD1” is set to the correct concentration. |
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| Calibration failure. |
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Sensor maintenance. |
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Has the sensor been refurbished per the manual’s procedure? It is recommended to be re-gelled at least every 3 months. |
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| Calibration failure. |
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Sensor cable not fully mated. |
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Check that the 4pin male/female sensor cable is firmly connected. Check temp. reading on analyzer to confirm they are mated. |
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| Calibration failure. |
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Ammonia not mixing with sample or standards. |
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Ensure bubbles are seen at bottom of steel straw coming from the entrainment. Check for pinholes or kinks in the tube from the buffer bottle to the entrainment. |
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| High/low readings. |
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Analyzer needs calibration. |
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The analyzer should be calibrated with standards every 2 weeks minimum. |
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| High/low readings. |
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Weak ammonia buffer. |
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Replace ammonia buffer. Ammonia should be replaced at least bi-monthly. Discard old ammonia, do not top off. |
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| High/low readings. |
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Ammonia not mixing with sample or standards. |
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Ensure bubbles are seen at bottom of steel straw coming from the entrainment. Check for pinholes or kinks in the tube from the buffer bottle to the entrainment. |
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| Current outputs (4-20mA) not working. |
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Current frozen more then 30 minutes after calibration. |
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Press the reset button. |
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| Current outputs (4-20mA) not working. |
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Range knob has been changed. |
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The 20mA output will correlate to the highest end of the selected range. |
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| Display flashes “out”. |
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Sample concentration exceeds selected range. |
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Select higher range. |
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| Display flashes “hot”. |
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Sample temperature exceeds 55 degrees C. |
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Reduce sample temperature. |
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| Display continually flashes reading that is within range. |
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Sensor nearing failure. |
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Sensor is passing calibration with a marginal current output. Perform sensor refurbishing procedure. |
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