The model 279 ISOPROBE® Electrostatic Voltmeter measures surface potential in the range of ±3000 volts without contacting the measured surface It features high-accuracy (0.1%), drift-free measurements that are almost fully independent of probe-to-surface separation. Its low-profile design is optimized for rack mounting of multiple 279′s in a minimum space.

Side- and end-viewing probes accommodate various mounting requirements. Specialty high-resolution probes allow the 279 to resolve spot diameters as small as 1 mm. Probes include air purge capability to prevent ingress of particulate.