Zero Offset Problem

If you are having a zero problem you will probably need service. The manufacturer is the best place for this. Try performing the calibration first to see how far the instrument is out of tolerance. The "calibration" of your viscometer can be completed following the procedure outlined on the manufacturers website. You will need a bath capable of holding 25.0C +- 0.1C. You will need a spindle that you will perform the calibration with. Finally you will need silicone standard solution in a 500mL low form griffin beaker. Following the manufacturers procedure and calculations and you should be able to determine if  your instrument is in tolerance.

Roger