Remote Lm335 Sensor Calibration - ILX Lightwave LDT-5500B Series User Manual

5
C H A P T E R

Remote LM335 Sensor Calibration

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 LDT-5500B Series
M A I N T E N A N C E A N D T R O U B L E S H O O T I N G
Calibration Adjustments
a Set the SENSOR SELECT switch (back panel) to the LM335 position. Set C1 to 0.00,
C2 to 1.00.
b Connect a precision 4 k metal film resistor and a precision voltmeter in parallel at
the sensor input of the LDT-5500B Series Temperature Controller (pins 7 and 8).
c Enter the sensor calibration mode by sending the command "TEC:CAL:SEN". After
this, the TEC display will indicate sensor reference current in mV. Wait for three
seconds for the measurement to settle.
d Send the command "TEC:R VALUE", where VALUE indicates the value measured by
the precision voltmeter mutiplied by 10. For example, if the voltage across the
resistor is 1.9871 Volts, send the command "TEC:R 19.87".
e Wait for the 7-segment display to flash off and then back on. Replace to 20 k
resistor with a 10 kmetal film resistor. Wait for three seconds, then repeat Step d
using the 10 k resistor.

Once the final sensor measurement is entered, the display will go blank. During this
step, the sensor temperature set point calibration is taking place internally. Allow the
instrument to self calibrate. Once completed, the calibration constants will be stored
to non-volatile memory, and the display will return to its previous state.
f After calibration, I LIMIT will be automatically set to 2.00 Amps. Reset the I LIMIT to
the desired value.