ET 35A - 15 PPM OIL CONTENT MONITOR - ZERO ADJUSTMENT
Upon opening unit in place, adjustment can be made to VR3 only [item # 7 on attached diagram] which is the zeroing potentiometer. We shipped unit with this potentiometer set to '5' on calibration chart [12 O'clock] . With clean potable water running as sample, you may try turning VR3 clockwise by increments of 1 , for at least 1 1/2 minutes for sampling time to readjust. That is intended to lower ppm until it reaches '0' on clean water.
CAUTION: when adjusting VR3 clockwise incrementally, do not adjust past '8' [3 O'clock] . This will cause actual reading to fall lower than zero ppm which cannot be displayed on the LCD.
If the above action does not rectify, then we would have to send out a replacement, and the one you currently have returned to us.
Tom. Mobile: (516) 808 0726.
Thomas Efthimiou, Manager
1044 Franklin Avenue, Suite 204
Garden City, New York 11530
Tel: 516 877 7410 ext 101
Fax: 516 294 4814