Single gas personal monitorSingle gas personal monitor

Single gas personal monitor

  • RKI - GasWatch3

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Why buy from Geneq? - find out more

The GasWatch 3 is the world's smallest and lightest single-gas monitor

Weighing just 1.6 ounces, its compact form affords great comfort and flexibility in how you choose to wear it. It can be worn on your wrist as a watch, or clipped into your breathing zone on your lapel, hard hat or other safety equipment with its alligator clip.

The 5 different GasWatch 3 models can protect you from oxygen deficiency [GW-3(O2)], exposure to carbon monoxide [GW-3(CO)] or exposure to hydrogen sulfide [GW-3(H2S)]. A hydrogen compensated model [GW-3(C-)] can protect those who work in steel mills, refineries or other environments where hydrogen is present from carbon monoxide exposure. The dual sensor model [GW-3(CX)] can simultaneously protect you from oxygen deficiency and carbon monoxide exposure.

A small, field-replaceable, coin-type lithium-ion battery gives the GasWatch 3 up to 4,000 hours of continuous operation. The hydrogen compensated CO can operate up to 2,500 hours, and the dual sensor CO/O2 model will get up to 2,000 hours of continuous operation.

The great battery life coupled with a 3-year warranty* gives the GasWatch 3 tremendous value and a low cost of ownership. *2-year for galvanic sensor on the O2 mode.


  • Refineries
  • Petrochemical facilities
  • Sewage treatment plants
  • Fire departments
  •  Chemical plants
  • Tunnels
  • Mines
  • Hazardous waste sites


  • 5 versions to choose from — CO, H2S, O2, CO/O2, or H2 compensated CO
  • 3-year warranty (2 years for O2 sensor)
  • Up to 4,000 hours of operation
  • Light and compact "watch type" design
  • Comfortably wear in your breathing zone
  • Available with watchband or alligator clip
  • Automatic backlight during alarm
  • Sturdy IP-66/68 rated design
  • Water, dust and radio frequency (RF) resistant
  • Non-compliance indicator


ModelGW-3 (HS)
Hydrogen Sulfide
GW-3 (CO)
Carbon Monoxide
GW-3 (C-)
H2 Compensated CO
GW-3 (CX) (Dual Sensor)GX-3 (O2)
Carbon MonoxideOxygen
ECDual ECGalvanic Cell
Detection Range
0 ~ 30 ppm (0.1)
30 ~ 100 ppm (1)
0 ~ 300 ppm (1)0 ~ 25.0% Vol. (0.1)
Service Range100 ~ 200 ppm (1)310 ~ 2,000 ppm (10)25 ~ 40.0% Vol. (0.1)
Alarm Setpoints1st: 5.0 ppm
2nd: 30.0 ppm
3rd: 100.0 ppm
TWA: 1.0 ppm
STEL: 5.0 ppm
OVER: 200.0 ppm
1st: 25 ppm
2nd: 50 ppm
3rd: 1200 ppm
TWA: 25 ppm
STEL: 200 ppm
OVER: 2,000 ppm
L: 19.5% Vol.
LL: 18.0% Vol.
H: 23.5% Vol.
OVER: 40.0% Vol.
Operating Temperature-20 °C to +50 °C (no sudden changes)
(Approx. 15-minute temporary use environment: -20 °C to +60 °C)
[no sudden changes]
-20 °C to +50 °C
(no sudden changes)
Humidity Range10 to 90 %RH (no condensation)
(Approx. 15-minute temporary use environment: 0 to 95 %RH)
[no condensation]
10 to 90 %RH
(no condensation)
Operating Time
Approx. 4,000 hoursApprox. 2,500 hoursApprox. 2,000 hoursApprox. 4,000 hours
Sampling MethodDiffusion Type
Types of AlarmGas alarms: Three-step alarms, STEL alarm, TWA alarm, OVER alarm


Fault alarms: Sensor connection / disconnection, low battery level, calibration failure, clock abnormality, system abnormality

Alarm IndicationsAuto-reset or self latching


Lamp flashing, intermittent buzzer sounding, gas concentration readout blinking, vibration

Power SourceCR2450 coin-type lithium ion battery
Case MaterialIntrisically safe explosion-proof construction (Ex ia IIC T4 Ga) , IP 66/68 (6.6ft, 1h) (2m, 1h)
ApprovalsATEX, IECEx, CSA
Dimension & Weight2.5″ W x 1.6″ H x .86″ D (Approx 63 mm W x 42mm H x 22mm D) , 1.6 ounces (approx. 45g)
FunctionsData logger, vibration, STEL alarm, TWA alarm, quick calibration, peak value display, temperature display
CR2450 coin-type lithium-ion battery, Spring pins (used to mount accessories on to the rear face),
Watch band, Alligator clip
Heat-resistant case, Dust filter, CF-1821 filter (for CO sensor),CF-A13i-1 humidity control filter (for H2S sensor),Calibration adapter