TWI-22: Loop-Powered Two-Wire 4-20mA Conditioner/Isolator         specsheet

  • High Input-Output-Power Isolation (800VAC Test)
  • Small Size - Fits Standard Explosion Proof Housing
  • Industry Standard 4-20 mA Input
  • Industry Standard 4-20 mA Output
  • Loop-powered from Input Loop, no Additional Power Supply Required
  • Drives up to 275 Ohms on Output Loop
  • High Noise Rejection
  • CSA and NRTL Approved (LR 51078)

The TWI-22 is a loop powered isolator in a small, easy to install package. It has easily accessible screw terminals and is built in a rugged housing that fits into standard explosion proof housings. It is ideal for applications where loop isolation is required but power is not available or space is confined. The output signal is generated from the incoming 4-20 mA signal which is isolated via a transformer. If the output is being driven into a 250 ohm impedance, the input to the isolator appears to be a 500 ohm impedance.

  • Isolation: Input to Output to Power 800 VAC (test)
  • Input: 4-20 mA
  • Output: 4-20 mA (275 Ohm max Load)
  • Accuracy/Linearity:+/- 0.25% max., +/- 0.1% typ.
  • Response Time: 10 msec to 63% of final value, 40 msec to 99% of final value
  • Operating Temperature: -20 Deg.C. to +50 Deg.C.
  • Temperature Effects: +/-0.25% max., +/-0.1% typ. (for 50 Deg.C. change)
  • Zero Drift: 1 uV/mV offset per Deg.C. or 1uV/Deg.C., whichever is higher
  • Loop Resistance Change Effects: -0.2% per 10 Ohms change (calibrated at 250 ohms)