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TM-10-6665-297-13P Bacharach Combustibles Gas Alarm System NSN 6665-00-410-4982 Manual | Next
Figure 1-22. CD802/832 Circuit Board: Relays and Adjusters for Dual-channel Systems |
TM 10-6665-297-13&P
1-3.3.2 Controls (continued)
4.
Channel Selector Switch (CD802/832 modules): Turned to AUTO mode: switches meter circuitry
to respond to channel with strongest signal. Turned to channel 1 or channel 2 position: switches
meter circuitry to respond to signal from selected channel. Alarm and warning circuits remain
active on both channels despite setting of channel selector switch.
1-3.3.3 Adjusters (Figures 1-19, 1-22):
1.
VOLT Adjuster: Potentiometer with adjustment screw; labeled VOLT on printed circuit board;
turned to adjust operating voltage applied to detector(s) from the voltage regulating circuitry of the
circuit board.
2.
ZERO Adjuster: Potentiometer with adjustment screw; labeled ZERO on printed circuit board;
turned to adjust signal voltage for zero meter reading with fresh air (containing no combustible
gases or vapors) at the detector(s). The CD800/830 circuit board has one ZERO adjuster (Figure 1-
19); the CD802/832 circuit board has two (one for each of the two independent signal channels,
Figure 1-22).
3.
GAIN Adjuster: Potentiometer with adjustment screw; labeled GAIN on printed circuit board;
turned to adjust signal amplification for accurate percent L. E. L. meter readings of concentrations
of specific gas or vapor to be monitored. Also turned to compensate for gradual depletion of
catalyst in the expendable detector sensor and the consequent slowly diminishing response. The
CD800/830 circuit board has one GAIN adjuster (Figure 1-19); the CD802. 832 circuit board has
two (one for each of two independent signal channels, Figure 1-22).
4.
TEST Signal Range Adjuster: Potentiometer with adjustment screw; labeled RANGE on the
CD800/830 printed circuit board (Figure 1-19), and TEST on the CD802/832 circuit board (Figure 1-
22). This adjuster is turned to obtain full-scale meter pointer deflection when the TEST pushbutton
is pressed.
5.
WARN Signal Trigger Point Adjuster : Potentiometer with adjustment screw; labeled WARN on
printed circuit board (all models, Figure 1-19, 1-22). This adjuster is turned to set a reference
voltage in a circuit that triggers the warning signal output circuitry when the gas signal rises to the
warning reference voltage level.
23-9617
7/1/76
1-33
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