Lamar Technologies Alpha C-25 - Manual (Page 15)

4. CALIBRATION AND MAINTENANCE
ALPHA C-25 Manual V2.1.doc Page 15
4. CALIBRATION AND MAINTENANCE
4.1 OVERVIEW OF CALIBRATION
The Alpha C-25 has been calibrated before shipment from the manufacturer. A
certificate of calibration with test instruments traceable to the National Institute of
Standards and Testing has been issued and is enclosed in the back of this manual.
To ensure error-free operation over time, calibration should be verified every 12
months depending on usage and changes in surrounding environment.
4.1.1 DIGITAL PANEL METERS
There are two main indicators that can be periodically verified: 1) the voltmeter;
and 2) the ammeter (see figure 1-1 in section 1). In addition the internal shunt,
even though calibrated and certified by the shunt manufacturer, could be verified.
4.1.2 TIMER
The timer is a very accurate crystal-controlled device, not prone to error. It cannot
be re-calibrated, but unless an extremely accurate time reading is required, an
accurate analog or digital stop watch is adequate to validate its accuracy.
4.1.3 OPERATING RANGES
The Alpha C-25 gives the capabilities with panel mounted trimpot to modify the
charge voltage in constant-potential mode. There is no adjust for voltage limit in
constant current.
4.2 VOLTAGE VERIFICATION
The Alpha C-25 Battery Charger now includes external test point jacks for
voltage and current verification.
Voltage Verification - Do not connect C-25 to battery. Select 28.5 V setting.
Using an external calibrated digital meter (set to DC Volt scale), connect to
voltmeter test jacks and verify voltage panel meter is within approximately
0.3 volts.
4.3 CURRENT VERIFICATION
Connect C-25 to a discharged battery and charge at approx. 20 Amps.
Using an external calibrated digital meter (set to millivolt scale), connect to
ammeter test jacks and verify panel meter is within approx. 0.3 Amps.