SEAL 2449537 - Caterpillar

(B) Accuracy Check Procedure
This procedure should be performed at least once a year to ensure the ammeter is within specifications. The following checks must be made with all components stabilized at a room temperature of 25°C 5°C (77°F 9°F).(1) Use 18 gauge or larger diameter wires (1) to connect the battery or power supply (2) to the 12 VDC terminals on the 5P8608 Calibrator (3). Be sure the + and - terminals on the battery or power supply are connected to the + and - terminals of the calibrator. Use standard test leads (4) of the 6V3030 Multimeter (5) to connect the multimeter to the voltmeter terminals on the calibrator. The COM terminal on the multimeter must be connected to the minus (-) terminal on the calibrator, and the V-Ohms terminal on the multimeter must be connected to the (+) terminal on the calibrator. Set Function/Range switch (6) on the multimeter to 20 DCV.(2) Plug leads (7) of 6V6124 Calibrator Coil (8) into the COIL jacks on the calibrator. Be sure to match the colors of the plugs with the jacks on the calibrator. Do not use the 5P8608 Coil supplied with the 5P8608 Calibration Group. This coil has too large a cross section diameter to be used with the 6V4910 Ammeter.(3) If a power supply is being used, turn on the power. Set the output at approximately 12 volts DC. If a battery is being used, make sure it is fully charged. Open the jaws of the ammeter and inspect the core closure points to be sure they are clean and free of all foreign material. If necessary, clean the points. Close the jaws slowly to avoid snapping the jaws.(4) Depress the power trigger on the ammeter and lock the trigger in the ON position. Let the ammeter warm up for several minutes. If the low battery indicator appears during the test, replace the batteries.(5) Put AC-DC mode switch (9) in the DC position. Open the jaws of the ammeter and place the 6V6124 Coil in the aperture of the ammeter. Make sure the arrow on the coil points in the same direction as the arrow on the ammeter. Close the jaws slowly. Move the coil slightly to be sure it is loose in the aperture and the jaws are tightly closed.(6) Put the ammeter in the position shown and keep the ammeter in this position during the entire test procedure.(7) Adjust DC ZERO control (10) until the digital display reads 000. With CURRENT SELECTOR switch (11) in position 1, press PUSH TO CALIBRATE button (12). Observe the reading on the multimeter and on the ammeter. They should be the same value within the error shown in the specifications. If necessary, correct the ammeter reading for accuracy; see chart on page 4. Do not keep the PUSH TO CALIBRATE button depressed too long or the coil will heat up.(8) Repeat the previous step for each CURRENT SELECTOR setting 2 through 6. IMPORTANT: When