5 Maintenance | Model 7300A | |
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C. Meter reads Negative
(with zero gas flowing through analyzer)
D. Meter Up Scale or Overscale
E. Insufficient Span Control (with span gas)
F. Noisy or Erratic
Operation
(a)ZERO control may be misadjusted.
Adjust control to bring indication up to zero. (refer to Section 4).
(b)If zero indication unattainable with ZERO control centered, monitor TP6 on preamp board.
(c)Check that infrared source is operating. If no light check source element resistance and connections.
(a)Redo full calibarion.
(b)Check for obstruction in sample beam path.
(c)Check for excessive moisture in plumbing and sample chamber. Clean and replace sample chamber.
(a)Recheck zero for excessive off- set.
(b)Check modulation factor using certified span gas.
The most eommon sources of noises are:
(a)Reduced output of infrared source (5v, 110 ma each) or replace as necessary.
Teledyne Analytical Instruments |