Electron and Ion Current Measurements with the 9103 USB Picoammeter

The 9103 USB Picoammeter available from RBD Instruments is a rugged, affordable, portable, and ASCII programmable instrument. It measures bi-polar DC current ranging from picoamps to milliamps.

The picoammeter has an optional integrated fixed +90 V DC bias, which reduces low energy secondary electron errors. The external bias option allows for current / voltage comparisons with the users’ own low-noise DC power supply.  The +5kV version can float up to +/- 5kV and is used for measuring the output directly from electron multipliers or biased collector arrays.

 Microsoft Windows 10 data logging and graphing software is provided. The 9103 USB picoammeter is compatible with LabView, Matlab, Linux, and Windows OSx, and can be controlled through a simple ASCII interface.

The instrument works well even in noisy settings. It was developed for measuring electron and ion beams, and also for characterizing diodes and IC I/V. The 9103 picoammeter is multi-channel capable — it can synchronize up to 127 channels.

The 9103 USB Picoammeter now comes in four configurations:

  • Standard — Sample rate 40 reads/second
  • High-voltage — Sample rate 40 reads/second, floats up to 5 kV DC*
  • High-speed — Sample rate 500 reads/second
  • High-speed/high-voltage — Sample rate 500 reads/second, floats up to 5 kV DC*

*High-voltage supply is offered by users
*Bias options are not available with the high-voltage version

The standard and high-speed models include two bias options:

  • External: BNC bias input
  • +90 V fixed


  • Measurements of photodiode current and dark current (up to 127 devices simultaneously)
  • Measurements of ion and electron current
  • Measurements of mass spectrometer current
  • Testing of leakage current
  • Testing of materials’ resistance
  • Comparisons of data logging current
  • Monitoring of beams and particles
  • Measurement of high resistance (with HV option)
  • Direct measurement of electron multiplier output (with HV option)


  • Manual or auto range — Selection of manual or automatic range
  • Programmability: ASCII command interface is included for user-defined testing and automation, and also for integration with third-party instrumentation software
  • Accurate measurement of current — Ranges from 2 nA to 2 mA, and 0.001 nA to 2.499 mA
  • Automatic input grounding — Prevents specimen stage from charging on vacuum spectrometers and electron microscopes
  • Interval or single sampling: Samples of current can be taken at timed intervals spanning from 25 ms to 9999 ms for each point
  • Optional high-speed sampling (500 reads/seconds)
  • Optional 5 kV DC isolation
  • Optional bias — Users can utilize their own isolated voltage source to quantify current versus voltage, or a fixed +90 V bias

the 9103 USB Picoammeter

Image Credit: RBD Instruments



Video Credit: RBD Instruments

Other Equipment by this Supplier