Teledyne 7120 - NDIR analyzer - Manual (Page 77)

5 Maintenance Model 7120
5-10 Teledyne Analytical Instruments
Board. Insufficient signal can be~
due to misadjusted Pl or sample
system pressure fluctuations
(vacuum).
F. Noisy or Erratic The most common sources of
Operation noises are:
(a) Reduced output of infrared source
(5v, 110 ma each) or replace as
necessary.
(b) Chopper hitting housing.
(c) Noisy detector.
(d) AC pickup at printed circuit
board.
(e) Optical unit not grounded to
cabinet.
(f) Detector connections loose.
(g) Faulty preamplifier board.
(h) Contamination in cell.