Arroyo Instruments TECPak 586 Series, Руководство пользователя

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586 TECPak User’s Manual · Page 25
User Calibration of Resistance Sensors
In some applications, having the ability to compensate, or calibrate, the sensor
measurement is desired, such as referencing to an internal standard or to match
the readings of another instrument. This is supported on the
TECPak by using
the TEC:USERCAL:PUT command to apply an offset and/or slope compensation
to thermistor or RTD readings.
To prevent accidental modification of the sensor calibration, calibration must first
be enabled with the TEC:USERCAL:EDIT command. By default, the slope and
offset values are 1.000 and 0.00, respectively, but can be adjusted to change the
sensor measurement. The calibrated measurement is computed as follows:
User calibrated reading = slope * r offset
The offset is kilo-ohms (k
Ω ) for thermistors, and ohms (k Ω ) for RTDs.
Controlling the Temperature Rate of Change
Some applications require that temperature is changed at a specific rate to
prevent damage that might otherwise come from rapid changes in device
temperature. Using the TEC:TRATE command, it is possible to control the
temperature ramp rate of the controller, limiting the rate of change to specific
degrees Celsius per minute.
Because the temperature rate function relies on the instrument tracking a
gradually changing set point, a proper gain setting (or PID values) is important
to achieve a smooth and continuous temperature transition.
To disable the temperature rate function, simply set the rate to 0 with a
‘TEC:TRATE 0’ command.
NOTE
The calibration is applied to the resistance measurement
of the sensor, not the temperature. To adjust the
resistance-to-temperature conversion, change the
thermistor or RTD coefficients as needed.