This post has been updated to include a video that shows how the High Voltage 9103 (PN 91035K) picoammeter can float up to +/- 5 kV.
RBD Instruments has released a new version of its 9103 USB Picoammeter which incorporates faster reads per second as well as 5000 DC volts of isolation to chassis ground.
Increasing the DC voltage isolation from chassis ground to 5000 volts (5kV) opens up new possibilities for researchers such as direct DC current measurement of very small electron and photo multiplier signals. Electron and ion beam measurements can be biased to reduce secondary electrons or to retard the beam as needed for experiments.
Designed to provide accurate bipolar DC current measurements in noisy environments such as synchrotron beam lines, the 9103 can measure bi-polar DC currents from low picoamps to milliamps.
The drawing below shows how the 9103 is floated on your HV power supply. The high voltage is referenced to chassis ground, and the signal ground is referenced to the high voltage. To help keep the supply and signal connections clear, the HV connection is a MHV connector and the signal input is a SHV connector.
There are a number of manufacturers of programmable DC power supplies that can be used to float the 9103 up to whatever voltage is needed (as long as you do not exceed +/- 5 kV).
For example, TDK-Lambda provides a programmable 0 to 6.5kV supply that can be voltage limited to 5 kV and can drive up to 2 mA of current.
The model number for a 120 VAC line input is PHV6.5P2-USB-1P115. The base model has a ripple of 700mV which is somewhat high, but TDK-Lambda does offer a low ripple option that gets the ripple down to 75mV. You can also easily make a simple RC filter to do the same thing. A number of interface options are available including USB, Ethernet, Serial and analog.
The new high speed option for the 9103 increases the reads per second from 40 to over 500, which is fast enough to perform optical chopper experiments. And, by taking more reads in the same amount of time as the first generation 9103 could, the accuracy is improved.
The Actuel software included with the 9103 provides new features for high speed acquisitions and display, but you can also write your own software to control the 9103 using the simple ASCII commands or in LabVIEW.
Since 9103s can be synced, it is now possible to configure a multichannel DC Picoammeter with up to 256 channels that has high speed, high voltage, or both options.
And if you do not need the high speed or high voltage options, the standard 9103 USB Picoammeter is still available as well.
For more information visit the RBD Instruments website at http://www.rbdinstruments.com