Five 9 Volt Batteries: With function switch at +DC volts and range switch at full scale reading closest to,
but not lower than 50 volts, connect Red (+) lead to exposed positive terminal (male) and Black (-) lead to
exposed negative terminal (female) of battery string. Record this open circuit voltage.
Place function switch in CUR or CAL mode, energize the current switch, and record the battery voltage
The voltage should remain at or slightly below the open circuit voltage. If the level should continue to
change value when the current switch is energized, the batteries are defective and should be replaced.
All five batteries should be replaced if any are defective.
Although a transistor radio battery (Leclanche' type) will work satisfactorily under most conditions, the
alkaline type (Mallory MN 1604 or equivalent) should be installed when the unit is used in adverse weather
conditions of cold ambient temperatures as they exhibit better voltage-current characteristics.
Introduction. Of first importance is that all plugs, panel connections, etc., be kept clean and dry. Moisture on the
panel plugs or cable plug can cause current leakage and result in improper operation of the gear. The same is true of the
cable and reel. Upon pulling the cable out of the well make sure it is wiped clean.
Maintenance of Resistively Instrument
The only maintenance other than cleaning required is the changing of batteries. The test set will tell you
when the 9 volt batteries need replacement. The 1 1/2 volt cell should be replaced every two months.
Access to the batteries is by lifting the instrument panel. The battery box will be seen in the bottom of the
case (see figure 2-1A).
In operating the instrument, care should be exercised so that the Ohmmeter and Self-Potential
Potentiometer dials are not slammed against their zero stops. When turned all the way counterclockwise,
they both should read exactly zero. If they do not, loosen the two set screws set 900 apart with the small
hex wrench which is taped onto the potentiometers. Reset the knob to zero.
Maintenance of Cable and Reel. In handling the cable, care must be exercised so that damage to the insulation
will not occur. The cable should always be wiped clean and when storing, it should be kept in a dry place until such time
that the cable is judged to be thoroughly dry.
INTERPRETATION OF ELECTRICAL LOGS
Preparation of the Log.
Basic to a proper interpretation of the electrical log data is the preparation of the graphical log. Any
suitable graph paper may be used.