TM 5-3820-256-10
g. Cable and Reel. The reel is made of aluminum. Wherever practical, nonferrous metals have been used in
construction of the logging gear.
h. Surface Wires. Two small lengths of insulated, stranded conductor wire are included with the unit. The surface
current wire has a red plug on one end that connects to CUR on the instrument, and a red clamp to fasten to a
grounded steel stake (not furnished) at the other end. The surface potential wire has a black plug on one end
that connects to POT on the instrument, and a piece of oxidized lead attached to the other end.
NOTE
If these wires should become worn or broken, they may be replaced by any 18-20 gauge, stranded
conductor, insulated wire. Because of the size of these lines (and their reel) they are not contained
within the instrument cases but are carried separately.
2-32.
Logging with NORMAL Arrangement.
a. Setting Up Equipment.
(1)
Set up the equipment as shown in figure 2-43. Plug the red and black plugs into the instrument (red in
CUR, black in POT), and extend each wire about 75 feet to opposite sides of the hole. The steel stake
should be 1/4 to 1/2 inch in diameter and 2 to 3 feet long. Drive the stake two-thirds into the ground and
attach the red clamp. Position the lead-oxide flag, equally distanced from the hole on the opposite side.
Attach the wire to the flag and bury flag and wire about 1 foot deep. Moisten and tamp the soil down firmly.
(2)
Before connecting the waterproof connectors on the probe and on the logging cable, clean both halves
thoroughly and make sure each is dry. Aline and mate the pins and socket; when properly mating, you
should hear a "POP" as the connectors join, (3) Lower the probe to the bottom of the well, being careful not
to let the probe "free-fall." Then connect the jumper cable into the cable receptacle on the instrument panel.
b. Operating the Instrument.
(1)
Calibrating. Set the function switch to the CAL position; set the electrode switch to one of the NORMAL
positions; hold the CUR switch in the ON position; and zero the galvanometer needle by adjusting the "cal
adjust" knob. Do this at the start of every job and repeat it after every 50 feet of logging.
2-101
