TREK Model 542A is a kind of ESVM, it can measure the surface voltage continuously.Also, you can set up the limited voltage,It will alarm when the surface voltage is over the limited voltage.And you can see the wave form if it is connected with the computer. It can set up the voltage detection system using wireless network.
Model 542A-1
Range:±10KV
Measurement distance:15mm~30mm
Accuracy:Better than 5% of reading,0.2% of full scale
Resolution:10V
Model:542A-2
Range:±20KV
Measurement distance:30mm~60mm
Accuracy:Better than 5% of reading,0.2% of full scale
Resolution:10V