The Trek Model 523 (±20kV) Hand-Held Electrostatic 
Voltmeters provide accurate, non-contacting measurements of electrostatic surface voltage for ESD applications in either ionized or non-ionized environments.

These two voltmeters utilize a measurement technique that overcomes the disadvantage of the typical hand-held field meter by providing surface voltage measurements which are essentially independent of the sensor probe to measure surface spacing. 

FEATURES
* Accurately measures the surface voltage at a wide range of spacings
* No need to maintain a fixed spacing
* Chopper stabilized for drift-free operation in ionized environments
* NIST-traceable Certificate of Calibration provided with each unit