Martel Electronics 235 - Manual (Page 30)

The internal temperature compensation is performed by a
semiconductor temperature sensor located next to the thermocouple
output terminals.
The external temperature compensation is performed in a special
external module that connects to the Model 230/235 calibrator’s ECJ
jack on the front panel.
If automatic compensation is selected, the calibrator will display the
current reference junction temperature reading.
Press any key to continue.
The calibrator will automatically use the external module if it is plugged
into the ECJ jack; otherwise, the internal compensation will be used.
The choice between internal or external is largely determined by
environment. The internal sensor is slower to respond to changes in
the ambient temperature. The external sensor, being outside of the
calibrator case, can respond to ambient changes more quickly. Also,
the external sensor can be extended to allow it to be placed in close
proximity to the device being calibrated and to allow connection to
short or inaccessible thermocouple leads.
Owner (Enter owner’s name)
The Model 230/235 calibrator contains a security feature that allows
the owner to enter a name or other identifying number into the
calibrator’s non-volatile memory. The owner’s name cannot be
changed unless the operator knows the unit’s access code. The access
code is unique to each calibrator and is printed on the individual
calibration sheet that is shipped with each calibrator.
Operation
230/235 25
Note: This module must be used to obtain specified accuracy.
Martel P/N 910200-001
Ref junc sensor
rdg °F + 72.0