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I404 Quad Current Integrator

I404 Quad Current Integrator


  • Four gated integrator channels
  • Dynamic range 1 pA to 1 mA
  • Integrated digitisation and filtering
  • Fibre-optic, RS-232 and RS-485 interfaces
  • Integrated calibration test source
  • Selection of current and charge integration modes
  • External trigger capability
  • Four independent analogue/frequency monitor outputs, configurable to show various analog parameters such as current, position
  • Optional high voltage output


  • Auxiliary HV output
  • Alternative feedback capacitor options


  • Quadrant photodiode readout
  • Low current and charge measurement
  • Beam position monitors


Parameter Value
Operating principle Gated integrator (charge integrating amplifier)
Integration capacitor Dual, software selectable in real time
Input noise < 100 fA rms + 1 fA rms per pF input load up to 100 pF
(1 second integration, 100 pF capacitor)
Input offset < 100 pA, 15 to 25 C. Offset can be removed by zero subtraction
Stability Output drift < 200 fA / C / hour
External accuracy Better than 0.5% of full scale in use, integration time 500 μsec to 1 sec, after calibration with built-in current source
Integration time User selectable, 100 μsec to 65 sec
Integration modes continuous charge/current, charge accumulation, triggered burst
External gate TTL 10 kohm impedance
Trigger modes Internal (autorun), external start, external start/stop, sternal start/hold, message
Digitisation 16 bit bipolar, 50kHz effective per channel
Built-in digital averaging gives 20 bit effective resolution for 32 integrations
Auxiliary HV PSU (Factory option) 0 to 1000 V programmable
(polarity and maximum voltage factory selectable), 1 mA max.
Noise and ripple < 0.1%
Power input +24 V (+/- 2 V) DC, 350 mA typ, 500 mA max
Controls Two rotary switches for loop address and comms mode/baud rate
Displays Status LEDs (power, device status, comms mode, data RX/TX) “HV on” LED
Case material Stainless steel sheet
Weight 1.64 kg (3.6 lb)
Operating environment 10 to 35 C (15 to 25 C recommended to reduce drift and offset), < 70% humidity, non-condensing, vibration < 0.1g all axes (1 to 1000 Hz) Vibration must be as low as possible to measure at the lower limit of the dynamic range
Shipping and storage environment -10 to 50 C, < 80% humidity, non-condensing,
vibration < 2g all axes, 1 to 1000 Hz
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