PROBLEM NO. 5: Same as Problem #4 above, except the simple push button calibration
always results in the same reading, which is incorrect (Too high or too
low), by 0.3% or more.
PROCEDURE &
EXPLANATION:
Check upper left corner of display for “LO BAT” indication. If okay, unit
needs factory calibration.
PROBLEM NO. 6: Display reads a value very close to zero (0.00) when unit is turned on in
normal air.
PROCEDURE &
EXPLANATION:
1.
If battery has been replaced, the memory circuits have probably
lost their charge and unit must be re-calibrated using the simple
push button procedure given in Section 7.0.
2.
If the simple push button calibration results in a reading close to
zero or zero, remove oxygen cell from sensor assembly following
procedure given under Section 6.0. Once removed, examine the
female connector attached to cell housing. Hold the cell housing so
that the “V” notch in the center ring of the connector is up. See
drawing A-2615-17. Connect the positive lead of a digital
voltmeter capable of reading millivolts to pin from the “V” notch.
The reading should be at least 13.5 millivolts or more. If the
reading is less that 12 millivolts, the cell has reached “end of life”
and should be replaced. If reading is above this value and reading
close to zero is obtained on the display, then a break in connection
(open circuit) probably exists in the gauging tape wires or
elsewhere. Use an ohmmeter to measure the continuity of the male
mating plug pins (3, 4, 6) connecting the red, black and white
wires to gauging tape 2 wire conductors and metal scale, back to
the hub electronics connection point.
PROBLEM NO. 7: Alarm circuit (Red LED or horn) does not function properly.
PROCEDURE &
EXPLANATION:
1.
Unit requires factory calibration.
2.
Horn may be badly corroded.
3.
Comparator is not functioning properly.
4.
Return to MMC or authorized service center for repair.
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