Table 4-3. Control Module Output Voltage for ppm

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FIGURE 4-9. Control Module Assembly.

TM-55-1905-223-24-18-2 Landing Craft Utility (LCU) NSN 1905-01-154-1191 Basic Craft Part II Manual

Table 4-3. Control Module Output Voltage for ppm-CONT.

TM 55-1905-223-24-18-2

b. Loosen two machine screws (5) and open side panel cover (4) on control module (3).

c. Hold alarm set switch (11) in SET.

d. Turn alarm set point adjustment screw (9) until desired reading is obtained on digital display (2).

Desired reading is indicated by calibration CAL CHECK (6).

e. Run clean water having a zero ppm value through sensing module.

f. Attach leads of test meter to terminal contacts 27 (+) and 28 (-) of terminal board (12).

g. When conditions have stabilized, a reading of 0 Vdc should be obtained. See Table 4-3 .

Table 4-3. Control Module Output Voltage for ppm.

ppm Indication (ppm)

Output Voltage (dc volts)

100

0.5

h. Release and swing aside REC (Receive) and DVM (Digital Voltmeter) adjustment guard (14).

i. Calibrate output as indicted above by adjusting recorder (REC) adjusting screw (13) while observing

voltage reading on test meter.

j. Remove leads of test meter from terminal contacts 27 (+) and 28 (-) of terminal board (12).

k. Adjust digital voltmeter (DVM) adjustment screw (7) to obtain proper ppm value on digital display (2).

Unit is now calibrated to read ppm.

l. Reinstall REC and DVM adjustment guard (14) in original position.

NOTE

Release knob lock before attempting to turn zero adjustment knob.

m. When oil-free water turbidity changes, this change can be calibrated out by running a sample of the

oil-free water through unit and adjustment of zero adjustment knob (8) to obtain a reading of 00 on

digital display (2).

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