Charge integration technique allows not losing any information on the charge received in a specific, user-defined integration time.
The AH401D is a compact 4-channel low noise picoammeter. It is composed of an extremely sensitive charge-integration input stage for low-current sensing, combined with a 20-bit sigma-delta AD converter with an integrated noise reduction digital filter.
This device is suited for very low current measurements, with 8 selectable input ranges spanning from 50 pA (with a 50-aA resolution) up to 2 µA (with a 2-pA resolution). Integration time is user selectable and ranges from 1ms up to 1s. Each input channel has two integrator stages so that the current-to-voltage conversion can be performed continuously during ADC conversion, avoiding any dead time in the data output. The simultaneous sampling of the 4 independent channels make this instrument ideal for beam position monitor applications or multichannel acquisition.
The new AH401D is housed in a light and extremely compact box that can be placed close to the signal sources in order to reduce cable lengths and minimize possible noise pick-up. Low temperature drift, good linearity and very low noise allow very high precision current measurements.
Remote Ethernet connectivity and easiness of configuration make the AH401D the perfect fit in many low-current multi-channel applications.
The picoammeter can be remotely controlled via a standard Ethernet 10/100 communication interface: integration time, range, data format, type of acquisition and many other parameters can be easily set and monitored.
The AH401D has an external TRIGGER input signal in order to synchronize the acquisition of the picoammeter with external events (e.g. laser triggering). Furthermore, digital samples can be transferred either using ASCII format or RAW binary data format for fast data transmission.