LAMAR BETA D-50 Operating Manual - page 23
5. CALIBRATION AND MAINTENANCE
J.
REMOVE THE COVER
If voltmeter differs more than ± 0.2 volts, remove the unit’s L-shaped cover by
unscrewing the four screws
a. Two on top left side of unit
b. Two on bottom right side of unit
WARNING:
Calibration needs to be performed with the unit’s cover removed
as well as both mains power and battery connected. It should only be
performed by trained personnel. If performed incorrectly it could result in
electrical shock leading to injury or death.
K.
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).
L.
REPEAT FOR ADDITIONAL VOLTAGES
To verify the accuracy over the range of the meter, additional voltages could be
checked. Since the Beta D-50 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 I but to turn up the discharge current to 1/3
of the rated ampere-hours (i.e. 13 amperes for a 40 ampere-hour battery).
5.3 AMMETER CALIBRATION
To calibrate the Beta D-50 ammeter, an external calibrated digital voltmeter, set to
the millivolt range, is required as well as a fully charged battery. The millivolt
meter will read the millivolts dropped across the Beta D-50 internal shunt when a
discharge current is drawn. The circuit diagram for the calibration can be seen in
figure 5-2. The calibration steps are outlined below.
BETA D-50 TESTER / ANALYZER - OPERATING MANUAL V2.2
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