CETAC M-7600 Mercury Analyzer Operator's Manual

Operator’s Manual
Chapter 6: Troubleshooting the Mercury Analyzer
‣ Check that the peristaltic pump rollers are not severely worn. Inspect all
rollers with tubing removed. Roller facets should not be “grooved.” All
rollers should spin freely when turned by sliding your thumb quickly
across them. None should feel “gritty” or slow in spinning. Replace the
head if any one of the 12 rollers are grooved or fail to move freely.
‣ Ensure the baseline is not drifting severely. (See page 140).
‣ Check that the raw analog system noise is ≤ 400 µAbs peak to peak. If not,
call CETAC Support.
Noisy Baseline
‣ Check that flows into and out of the Gas-Liquid Separator are not pulsing.
Pulsation indicates improperly adjusted pump clamps.
‣ Make sure the gas pressures are correct.
‣ Be sure the SnCl 2 is fresh and not oxidized or precipitated.
‣ Ensure the cell windows are clean.
‣ Check that the EOFM filter is clean. Turn the Hg lamp off and ensure that
the EOFM filter is not dirty (inspect it with a dentist’s mirror and low
angle flashlight).
‣ Check that nothing has been spilled on the binocular camera lenses. Turn
the Hg lamp off and ensure that the camera lenses are not dirty (inspect
them with a dentist’s mirror and low angle flashlight). Call CETAC
Customer Service and Support if the camera lenses are dirty.
Ensure the lamp current is not excessive. For more information see “Adjusting
the Lamp Current” on page 129.
Bad DL
‣ Check Low Absorbance. See “Low Absorbance or No Mercury Response”
on page 141 and “Double Peak with Low Absorbance” on page 142.
‣ Check noisy baseline. See page 144.
Sudden Standard Absorbance Rise During Run
‣ Ensure the rinse bottle has acidified rinse.
144