Martel Electronics 135 - Manual (Page 51)

puts the calibrator in series with the 4 to 20 milliamp loop. Plug the
test leads provided with the calibrator into the jacks marked “Loop
Power” on the LPS and connect them to the instrument under test,
with proper polarity (+ to + / - to -).
The batteries of the LPS can be checked by plugging the same special
cable provided with the LPS from the plug marked “Battery Charger” on
the LPS, to the V input jacks on the calibrator. When voltage is selected
on the keypad, the LPS battery voltage will be displayed on the
calibrator.
The LPS battery voltage should be between 10.6 and 9.2 volts. When
the voltage falls below 8.8 volts, the LPS will automatically turn itself
OFF to prevent damage to the batteries due to possible cell reversal.
Output Functions
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