A low-cost 3½-digit liquid crystal display readout of Electron Beam Probe Current. The free-standing meter is battery powered and measures from below 1pA to 2μA in 5 switched ranges. The meter has automatic zero correction but there may be small residual error not exceeding 5pA at 25°C. Where absolute readings are required on low ranges this small error may be subtracted from the reading obtained.

The input is designed to accept large overloads in excess of 100μA without sustaining damage. Its small size allows the unit to be easily located near the SEM itself.