C H A P T E R 2
O P E R A T I O N
Introduction to the
The temperature is limited (via the sensor feedback) to the T LIMIT value. If the sensor reads a temperature which is greater than T LIMIT, the I TE output will be shut off.
The GAIN value is used to control the sensor feedback gain, and thus the temperature settling time and overshoot. If the GAIN is set too low (1 is the lowest setting) the TE cooler will take longer to reach the temperature set point. If the GAIN is set too high (300 is the highest setting) the actual temperature may oscillate around the set temperature.
The optimum GAIN setting depends on the type of TE cooler and temperature that you are setting . Set the GAIN to its lowest value and then try increasing it until the temperature oscillates around the set temperature. Then, reduce the GAIN one step.
Parameter Setup
The PARAMETER switch is used to view and edit the parameters. Repeatedly pressing the PARAMETER switch will cycle through the parameters.
When a parameter is selected for viewing, its value will remain on the display for three seconds. If an adjustment is made to the parameter (by turning the adjust knob) the three second timer will be restarted. Three seconds after the parameter adjustment is done, the display will revert to the last measurement mode.
SENSOR CAL
These are the constants of the
When a linear sensor device (such as an AD590 or LM335) is used, a linear equation is used. If a linear sensor's calibration is not known, set C1 = 0.00, C2 =
1.00.For more information on linear sensor calibration, see Appendix C. The range of values for C1 and C2 are
To read C1 or C2, press the CAL button until it sequences to the desired constant. The C1 or C2 indicator will become lit to indicate which constant is selected. To change the value, turn the ADJUST knob until the correct value is displayed.
Appendix A contains an explanation of the
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