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JC Controls  P.O. Box 607, Orinda, CA 94563   (925) 939-8877 | fax: (925) 939-8883

Calibration Instructions

for JC Controls, LN₂ Level Controllers

Calibration procedures are simple and require only a DC volt meter with a range of 0 to 100VDC, and a small slotted screwdriver. Depending on the model of controller there will be from one or two sensors that will need to be calibrated.

• SN1-7, SN1-7A, SN1-7OA, SN2-7,
• SNT-7, SNT-7A, SNT-7OA, SNTDF-7, SNTDF-7A, SNTDF-7OA

1)     Place all of the sensors into LN2 and turn on the PC board ( complete units set power switch to Auto ).

2)     Set your DC volt meter to a scale of 0 to 100VDC or greater.  Find the  diagram that matches your board. Connect the (-) lead of your meter to point (A), then connect the (+) lead to point marked (B).

3)     Adjust Potentiometer B until the voltage is 67 VDC. 

4)     For boards with more than one sensor, repeat steps 3 & 4 for points (C) & (D) if applicable. Keep (-) lead on point (A).

5)     Use the edge connector for alternative test points. (-) is pin 6, (+) pin 12 for B and pin11 for C.