TM5-3820-256-10
Table 3-11. Troubleshooting the Logging Instrument (Cont'd.).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
2.
FLUCTUATING "SP";
Step 1. Check for
Repair or replace broken, frayed,
GALVANOMETER NEE-
poor or bad connec-
or damaged wires.
DLE WILL NOT
tion in lead-oxide
STEADY.
flag wire.
Step 2. Check that
Bury flag in moist soil; tamp
flag is properly
down soil firmly.
buried.
Step 3. Stray
Use LATERAL arrangement of
ground potential.
electrodes.
3.
CANNOT ZERO METER
Step 1. Check for
Try reversing the SP polarity
WITH SP POTENTIO-
proper polarity.
switch.
METER.
NOTE
SP polarity may change during
logging.
Step 2. Check for
Check 1-1/2 volt "C" battery;
low battery.
replace if necessary.
4.
NO METER RESPONSE
Step 1. Check for
Re-insert connections and sur-
TO SP POTENTIOMETER.
bad connections.
face lines, particularly the po-
tential surface line connected to
lead flag.
Step 2. Check SP
Push the button up and down a
shut-off switch is
couple times to release the
not stuck in OFF
switch.
position.
5.
METER DEFLECTION
Check for moisture
Apply a source of warm, dry air
WITH NO CONNEC-
affecting current
to the switch. If this happens
TION.
switch.
frequently, install a rubber boot
on the switch.
NOTE
If this condition exists although
the test set indicates proper
calibration, the instrument may
function properly when current
switch is activated.
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