Tech Notes
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Title: Troubleshooting the 7102 heating/cooling element
Created: 10 Apr 2012
Last Revised: 10 Apr 2012
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Applies To: 7102 Micro-Bath Thermometer Calibrator
Problem Description: The 7102 will not heat to the maximum or minimum temperature.
Resolution/Work Around: The 7102 block has two heating/cooling circuits, one for each side.
- Drain the fluid from the tank.
- Set the 7102 to 25°C and let it stabilize for a few minutes.
- Then, set the 7102 to 50°C.
- As the unit starts to rise in temperature feel the air temperature from the heatsinks or place your fingers just inside the left and right side of the tank and feel the temperature.
- If one side is cool and the other is getting hot, then the block may be open.
- Disconnect the power.
- Remove both sides; there are 2 screws on the bottom, 4 in front, 4 in back, and 1 in the handle rod.
- Now, remove the 2 screws from the top of the front panel and two screws from the bottom of the front panel.
- Locate the 4 pin connector with a red, black, red/white, and red/white/black wire.
- With a good ohm meter measure the resistance between the red to black wires and then the resistance between red/white to red/white/black wires or in other words pins 1 to 2 and then 3 to 4.
- You should read about 10 ohms depending on the temperature.
- If one side reads OL, or ……. (all dots), or something like 26 M?, this indicates an open and the block is bad and needs replaced.