TM 5-6635-386-12&P
Unpacking
Damage upon receipt is the responsibility of the freight
company. A claim should be filed with the freight
company for damage. If the radioactive source may
have been damaged, see Para 4-31.
1-1. GENERAL OPERATION
The tester is ready for use after unpacking.
There are no adjustments in the tester. All settings are
factory set and sealed.
Batteries will be removed from tester and placed in the
shipping case, whenever the tester is not in operation or
is being shipped overseas. BATTERIES WILL NOT BE
LEFT OR STORED IN THE TESTER. Refer to Section
III for instructions.
If the batteries are low, a letter "L" will appear in the
display. If the batteries are very low, the tester will
"cutout". The "L" will appear, but the gauge will not
operate. Recharge or replace the batteries (NICAD
batteries only-NSN 6140-00-497-0490).
Charge the tester overnight when the batteries indicate
"L" or low. The battery charger will not damage the
batteries by overcharging.
A satisfactory program would be to charge the tester
over a weekend once or twice a month depending upon
use.
CAUTION
Due to excessive damage caused by battery leakage,
only NICAD batteries, NSN 6140-00-4970490, will be
used as battery replacement. Quantity of eight (8) each
should be ordered.
WARNING
*
Do not attempt charging alkaline batteries.
Alkaline batteries are not to be used in the
tester.
*
Do not attempt charging zinc-carbon batteries.
zinc-carbon batteries are not to be used in the
tester.
Shipping Case
The shipping case is a fiberglass case with integral,
molded foam padding (see Para 3-7 for shipping case
maintenance).
Reference Standard The reference standard is a
separate standard with the fiberglass case.
Reference standards are serialized for each tester,
however, they are interchangeable between testers.
Guideplate
The guideplate is cast aluminum. It is entirely adequate
for all surfacing and for support of the drill pin during
transmission hole preparation.
Do not use the plate to remove the drill pin.
Drill Pin The standard drill pin is 3/4 inch diameter with a
forged head.
1-2. MODES OF OPERATION
BACKSCATTER is the technique of placing source on
the surface of a flat material. This technique measures
only the top 2-inches of soil and is very sensitive to
surface roughness or quality of site preparation.
TRANSMISSION is the technique of pre-drilling a small
hole in the ground and then inserting the radioactive
source in the ground via the movable source rod. This
technique permits measurement to specific depths to 12-
inches and is insensitive to surface roughness. It is very
accurate and is the preferred method of measurement
for soils.
DENSITY is measured by backscatter or transmission.
MOISTURE is measured by backscatter only. It is not a
transmission phenomenon. The tester uses a separate
source in the bottom casting to insure constant
1-2
