Fisher Temperature Controller, Setting the Temperature Units Select Calibration Offset

Isotemp￿ Laboratory and Chromatography Refrigerators Page 6 of 12

Temperature

Controller

Setting the Temperature

Units Select

Calibration Offset

Part Number: 104416

Begin operation by inserting the key into the key switch located on the header panel. The key switch is packed inside the envelope, which is shipped in the refrigerator chamber. Turning the key switch to the ON

() position will energize the evaporator fans and the digital controller.

The digital temperature controller is located on the left side of the header panel (See Figure 4). When the unit is initially turned on, the display will indicate current chamber temperature. The temperature units will be indicated by the °C or °F LED located just to the right of the temperature display. The refrigerator is factory set at 4°C. When the unit is first energized the evaporator fans will operate however it will not immediately cool. A 3-minute compressor delay is programmed into the controller to provide sufficient time for the evaporator to defrost and to allow the system pressure time to equalize. When the delay time is over, the Cool LED will illuminate, the compressor will run and the chamber will cool.

NOTE: The compressor requires a 3-minute delay time between activations. The unit will not cool during this

delay. The delay is also activated when the controller is first energized.

To change the set temperature, press and release the Menu keypad once. The display will flash SP and the Mode LED will be illuminated. The last set temperature will then be shown in the display.

To change the temperature, press the UP or DOWN arrow key. The adjustable temperature range is 1 to 12°C (34 to 54°F). When the desired set temperature is displayed, press the Menu keypad to enter the set temperature and activate the Units Select menu.

The second menu selects the units. The refrigerator control displays temperature in °C or °F. The factory setting is °C. Starting from the temperature display mode (Mode LED off), press the Menu key twice. The current temperature units are displayed. To switch between units, press the UP or DOWN arrow key then press the Menu key to select. The unit LED will be displayed on the right of the temperature display.

In the event the refrigerator needs to be calibrated, a simple routine is available to adjust the display and control point to a referenced standard. To set a temperature offset, press and hold the Menu keypad for 5 seconds. The display will flash oS followed by the last temperature offset value. The factory setting is 0. To change the offset value, press the UP or DOWN arrow key, then press the Menu key. The value shown in the display will be added to the previous temperature reading. The display will then flash Ho.