SEM104TC Datasheet, PDF (5/8 Pages) List of Unclassifed Manufacturers – SEM104 SERIES

STEP 5. RE-CALIBRATE
a.
Look up your SPAN & TRUE-ZERO temperature in the tables overleaf and note the links that need
to be made. Using a soldering iron blob the links on the PCB. Ensure any links not called up,
soldered from a previous range, are open circuited by removing the solder blob. Note you will
need to remove the enclosure base to gain access to the links. There are 8 links in total, ABCD
affect SPAN and WXYZ affect TRUE-ZERO.
b.
Set the resistance box to the equivalent sensor resistance for the temperature you require for
4 mA output. Adjust the Z zero trim potentiometer for 4.00 mA ± 0.01 mA output current.
c.
Set the resistance box to the equivalent sensor resistance for the temperature you require for
20 mA output. Adjust the S span trim potentiometer for 20.00 mA ± 0.01 mA output current.
d.
Repeat Steps b & c until both points are in calibration. Note some interaction between
adjustments will occur.
e.
Switch off power and remove wires. Mark transmitter with the new range.
EXAMPLE
1. Range (50 to 200) ºC.
2. Span = 200 - 50 = 150
3. True Zero = 50 - (150/4) = 50 - 37.5 = 12.5
4. Span falls in 140 to 215 range therefore link B is made.
5. True Zero falls in (-1 to 18) °C range therefore links X and Z are made.
6. Check that all other links are open circuit.
SEM104TC
THERMOCOUPLE TEMPERATURE TRANSMITTER
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