Time Electronics 5051 Plus - Reading Hold; Nulling a Reading; Thermocouples and CJC; Exiting Xx51 Multimeter Mode

Time Electronics User Manual
5051 Plus and 7051 Plus Multifunction Calibrators v2.1
xx51+ Multifunction Calibrators Page 53 of 64
7.11.4. Reading Hold
If you wish to hold the display reading, click on the HOLD button. To indicate that Hold is active, the
HOLD button will be highlighted and a HOLD annunciator will light up in the display window:
While in HOLD state, no further readings will be taken – the green star in the display window will not
flash and the value in the reading window will remain unchanged from the last value read before the
HOLD button was pressed.
To release HOLD and begin taking readings again, click the HOLD button again. Note that HOLD will
also be released if a new range or function is selected.
7.11.5. Nulling a Reading
The xx51 multimeter includes a NULL feature to allow backing off a reading, e.g. for cancelling out
end or lead resistances.
When you click the NULL button, the current reading becomes zero and all future readings displayed
are subtracted from this value.
For example, to measure the resistance of a component without measuring the resistance of the
connecting leads,
1. With the Ω2W function selected, select the required range.
2. Short the connecting leads together at the point where they will connect to the component. The
display will then indicate the lead resistance.
3. Click the NULL button once. The message “Null On…” will appear for approx. 2 secs, the NULL
button will highlight and a “NULL” annunciator will appear in the display window. Remove the
short from the leads and connect the component.
4. The reading displayed will be the component resistance only and not include the lead resistance.
To remove NULL click again on the NULL button. Please note that unlike the HOLD feature NULL is
not cancelled when a new range is selected but is cancelled if a new function is selected.
7.11.6. Thermocouples and CJC
The xx51 DMM control has a Cold Junction Compensation feature.
Auto: The xx51 uses an internal temperature sensor.
Manual: The user enters the cold junction value manually via the keypad
Off: No compensation.
If a 7085 temperature distribution panel is fitted the option to take the CJC value from here is also
available.
7.11.7. Exiting xx51 Multimeter Mode
Click once on the EXIT button. You will be returned to the Windows desktop.