The GDS-49 is a two-wire loop-powered 4-20mA sensor transmitter designed to detect a wide range of toxic gases at ppm levels. The current loop output is compatible with the C1 Protector, C2 Protector, C2 Quad Protector or C64 Protector Controllers, the GASMAX II or GASMAX CX gas monitors or any other device with a 4-20mA input and built-in calibration capability.

The GDS-49 is CSA certified for installation in Class I Div 1 areas as Explosion Proof or as Intrinsically Safe when used with an approved IS barrier.

Missing or defective sensors are detected and flagged by transmitting a value of less than 2mA to the receiver.

The GDS-49 functions with loop voltages ranging from 9 – 36VDC and an integral transient voltage suppressor protects the GDS-49 in the event of lightning or other electrical surges.

Brochure Manual


  • Field replaceable sensor for easy maintenance
  • Fault Supervision” circuitry continuously checks for failed or missing sensor
  • High immunity to electrical noise and interference
  • Industry standard two-wire 4-20mA loop signal for long distance transmission
  • CSA certified for Division 1 & 2 hazardous areas.
  • Depending on sensor, may be installed intrinsically safe device with IS barrier or explosion-proof
  • Easy interface to all GDS Corp. controllers or transmitters with 4-20mA inputs
  • No polarized wiring with protective “steering diode” interface