Lamar Technologies CA 1550 - Manual (Page 29)

5. CALIBRATION AND MAINTENANCE
G. COMPARE VOLT READINGS
Compare the CA-1550 digital voltmeter
reading with the external calibrated voltmeter.
a. If readings differ less than ± 0.2 volts, the
voltmeter is accurately calibrated. Turn
AC power off.
b. If readings differ more than ± 0.2 volts,
continue with steps I through K.
H. OPEN THE CA-1550
If voltmeter differs more than ± 0.2 volts, open the front panel of the
CA1550 by removing the two screws on the right side of the panel.
WARNING: Calibration needs to be performed with the unit’s cover
removed and mains power connected. It should only be performed by
trained personnel. If performed incorrectly it could result in electrical shock
leading to injury or death.
I. CALIBRATE VOLTMETER
The voltmeter can be found on the back
side of the front panel. Locate the
voltmeter trimpot.
Using a 1/16 inch (2 mm) slot blade
precision type screw driver, adjust the
embedded trimpot located at the rear of
the voltmeter.Adjust until voltmeter
reading matches that of the calibrated
voltmeter (at least within ± 0.2 volts).
J. REPEAT FOR ADDITIONAL VOLTAGES
To verify the accuracy over the range of the meter, additional voltages could be
checked. Since the CA-1550 digital meters are linear, checking two or
three voltages are adequate to verify the range. The easiest way to check
an additional voltage is to repeat step H but adjusting the Constant Potential
Adjust Trimpot to another voltage (see section 3.5 on how to Modify
Constant Potential).
CA-1550 CHARGER / ANALYZER - OPERATING MANUAL V1.2 Page 27