Teledyne gfc 7000ta operation manual Calibration Problems, Miscalibrated

Troubleshooting Model GFC7000TA Carbon Dioxide Analyzer

10.3. Calibration Problems

10.3.1. Miscalibrated

There are several symptoms that can be caused by the analyzer being miss-calibrated. This condition is indicated by out of range Slopes and Offsets as displayed through the test functions and is frequently caused by the following:

1.BAD SPAN GAS. This can cause a large error in the slope and a small error in the offset. Delivered from the factory, the GFC 7000TA’s slope is within ±15% of nominal. Bad span gas will cause the analyzer to be calibrated to the wrong value. If in doubt have the span gas checked by and independent lab.

2.CONTAMINATED ZERO GAS. Excess H2O can cause a positive or negative offset and will indirectly affect the slope.

3.Dilution calibrator not set up correctly or is malfunctioning. This will also cause the slope, but not the zero, to be incorrect. Again the analyzer is being calibrated to the wrong value.

4.Too many analyzers on the manifold. This can cause either a slope or offset error because ambient gas with its pollutants will dilute the zero or span gas.

Teledyne Analytical Instruments 235