Martel Electronics 235 - Manual (Page 62)

All of the output features such as Auto, CalPts and Ramp are available
for use with the module.
Ohm/RTD Module (Optional)
The OHM/RTD Module allows output simulation of 1 to 900 Ohms by
using the calibrator input to set the pots on the Module. Plug the
umbilical from the Module into the Ohms input of the Model 230/235
calibrator and select 4-wire Ohms input. Move the switch on the
Module to the Set position and set the desired output using the coarse
and fine pots. Once the reading is achieved, move the switch to the
Simulate position. Connect the instrument under test to the jacks on
the OHM/RTD Module. Accuracy is the same as the Model 230/235
calibrators, resolution is better than .03 ohms.
Loop Power Supply (Optional)
The Loop Power Supply (LPS) is an option that provides 24 VDC to
power a device under test. The LPS is shipped with the batteries in an
uncharged state.
The battery charger for the LPS is different from the one supplied with
the Model 130/135 and 230/235 calibrators. Consult page 91 for
proper part number.
The LPS contains eight (8) AA Ni-Cd batteries that provide power to a
DC to DC converter. This converter boosts the battery voltage (10.6 to
9.2 volts) to 24 VDC +/- 5%. The LPS is intended for use as a power
supply for any two wire, 4 to 20 milliamp instrument requiring 24 VDC
power. Battery life is 6 hours nominal at 20 milliamps. Full
specifications can be found on page 91.
Output Functions
230/235 57
Note: Before using the LPS as a portable unit, it is necessary to
charge the batteries for a minimum of 14 to 16 hours.