GE CTR 80 manual New proportional band setting

9 Controller Operation

down. In this way the temperature is maintained at a fairly constant temperature.

The temperature stability of the bath and response time depend on the width of the proportional band. If the band is too wide the temperature will deviate ex- cessively from the set-point due to varying external conditions. This is because the power output changes very little with temperature and the controller cannot respond very well to changing conditions or noise in the system. If the propor- tional band is too narrow the temperature may swing back and forth because the controller overreacts to temperature variations. For best control stability the proportional band must be set for the optimum width. This value is usually two to three times the largest value at which the bath temperature oscillates.

The proportional band width is set at the factory to a value between 0.5 and 1.0°C. The proportional band width may be altered by the user if he desires to optimize the control characteristics for a particular application.

The proportional band width is easily adjusted from the front panel. The width may be set to discrete values in degrees C or F depending on the selected units. The proportional band adjustment is be accessed within the secondary menu.

Press “SET” and “EXIT” to enter the secondary menu and show the heater power. Then press “SET” to access the proportional band.

S+E Access heater power in secondary menu

SAccess proportional band

ProPFlashes “ProP” and the setting

15.0Proportional band setting

To change the proportional band press “UP” or “DOWN”.

1.5New proportional band setting

To store the new setting press “SET”. Press “EXIT” to continue without storing the new value.

SAccept the new proportional band setting

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