Teledyne 7320 - NDIR analyzer - Manual (Page 79)

Infrared Gas Analyzer Maintenance 5
5-7 Teledyne Analytical Instruments
put is either dead or
fully saturated.
(b) Check that power supply voltages
are correct (+15VDC, Ä15VDC).
(c) Check that infrared source is
operating. If no light, check
source element resistance and
connections.
(d) Try to execute a manual zero.
C. Meter reads Negative (a) ZERO control may be
misadjusted.
(with zero gas flowing Adjust control to bring indication
through analyzer) up to zero. (refer to Section 4).
(b) Check that infrared source is
operating. If no light check source
element resistance and connections.
D. Meter Up Scale or (a) Redo full calibarion.
Overscale
(b) Check for obstruction in sample
beam path.
(c) Check for excessive moisture in
plumbing and sample chamber. Clean
and replace sample chamber.
E. Insufficient Span (a) Recheck zero for excessive off-
Control (with span gas) set.
(b) Check modulation factor using
certified span gas.
F. Noisy or Erratic The most eommon sources of