If the Tare value is off significantly from this, it could be any of the following reasons. Transducer is not plugged in. Transducer is not level. On many microscopes, there is a 3 point leveling system to align the tip with the surface. If it is not level, gravity will cause the center plate of the transducer to displace less, showing a lower Tare value.
Transducer is damaged.
It will need to be sent back to Hysitron for repair. These can be used with any microscope, or Stand Alone system. When there is no signal, the amplifiers in the box begin to oscillate, causing an unstable display. If this is not the problem, there is most likely an internal problem with the transducer or the box, and it needs to be sent back to Hysitron for repair. The best way to clean the diamond tip is to use Acetone or other solvent and a cotton swab.