Lake Shore 234, Руководство пользователя

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Lake Shore Model 234/234D User’s Manual
Service 5-7
3. Preparation.
a. Connect the 1 k
Ω
calibration resistor to the screw terminal SENSOR
I+ and SENSOR I– to simulate a sensor load to the Model 234. Use
a shorting wire to connect SENSOR I+ to SENSOR V+, and another
shorting wire to connect SENSOR I– to SENSOR V–.
b. Connect the 500
Ω
resistor to the screw terminal to simulate an
output load to the Model 234. Use the OUT+ and OUT– pins.
c. Set the T/R switch (7) to the R position (closed) and the I/V switch to
the V (closed) position.
d. Power the Model 234 Temperature Transmitter with the 5 VDC power
supply.
4. General Input Test. The following test steps are recommended prior to
calibration to verify that the Model 234 Temperature Transmitter current
source and input stage operate properly:
a. Verify the 1 k
Ω
calibration resistor is connected to the screw terminal
SENSOR I+ and SENSOR I– and shorting wires connect SENSOR I+
to SENSOR V+, and SENSOR I– to SENSOR V–.
b. Connect the DVM negative lead to OUT–, and positive lead to OUT+
of the Model 234.
c. Make sure that the I/V to the V position (closed), and the T/R switch
to R (closed).
d. The DVM should read near 5 volts which is 10 × log(1000) / 6.
e. Remove the 1 k
Ω
from the SENSOR I+ and SENSOR I– screw
terminals. The DVM should read about 0 volts.
f. Put a short between the SENSOR I+ and SENSOR I– screw
terminals. The DVM should read about 10 volts.
5.4.3 Calibration Procedure Using Range Switches & Pushbutton S2
Model 234 calibration consists of output calibration and input calibration.
NOTE: Allow about 30 minutes for the Model 234 Temperature Transmitter
to warm up before continuing with calibration.