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GasWatch 2

Hands Free Single Gas Monitor


GasWatch 2The GasWatch 2 is the first single-gas monitor that can be comfortably worn on the wrist like a watch. The GasWatch 2 is a convenient, inexpensive, hands-free method of gas monitoring for personal protection of oxygen deficiency, carbon monoxide or hydrogen sulfide. The built in vibrator, audible, and visual alarms immediately alert the user of a dangerous gas condition.

The GasWatch 2 is controlled by a microprocessor for reliability and advanced capabilities. Some of these advanced capabilities include distinctive audible and visual alarms for dangerous gas conditions and malfunctions, a large digital readout with a manual backlight that also automatically lights in an alarm condition, as well as the display of PEAK, TWA, and STEL readings. The replacement sensors are inexpensive, easily field replaceable and have a life expectancy of about 2 years. Equipped with a watch band, optional belt clip or hard hat clip, the GasWatch 2 can be worn either on the wrist, belt, or hard hat.

The GasWatch 2 will operate for over 3000 hours on one battery (about 1 year normal use). And yes, the GasWatch 2 even tells the time!

  • Features
  • Specifications
  • Downloads
  • Video



  • Hands free gas monitoring
  • 3 Gases to choose from CO, H2S, or O2
  • Compact "watch type" design
  • Vibration, visual and audible alarms standard
  • Over 3,000 hours of operation from 1 battery
  • Fast, accurate response with digital LCD display
  • Fits on your arm, wrist, or belt
  • Manual backlight (Automatic light during alarm)
  • Sensor fail alarm
  • PEAK hold function (Max. value during operation)
  • TWA and STEL function
  • Displays current time
  • 2 Year warranty
  • Worker Safety
  • Chemical Plants
  • Hazardous Waste Sites
  • Mines
  • Tunnels
  • Sewage Treatment Plants

Gas Watch


Model Name
(Part #)
Oxygen (O2) Hydrogen Sulfide
Carbon Monoxide (CO)
Galvanic cell Electrochemical
Sensor Type OS-BM2 ES-1827 ES-1821
0 - 40.0% vol.
(0.1% vol.)
0 - 100.0 ppm
(0.5 ppm)
0 - 500 ppm
(1 ppm)
Alarm Points
(Factory Set)
Low - 19.5% vol.
High - 23.5% vol.
Over - 40.0% vol.
1st - 10.0 ppm
2nd - 30.0 ppm
TWA - 10.0 ppm
STEL - 15.0 ppm
Over - 100.0 ppm
1st - 25 ppm
2nd - 50 ppm
TWA - 25 ppm
STEL - 200 ppm
Over - 500 ppm
Alarm Types Gas alarm: 2 step alarm, STEL, TWA, Over alarm
Trouble alarm: sensor connection, low battery, circuit error
Calibration range over alarm
Alarm Indication Gas alarm: flashing light, intermittent buzzer and pulsing vibration
Trouble alarm: flashing light, intermittent buzzer and trouble type displayed
Response Time T90 in 20 seconds T90 in 30 seconds T90 in 30 seconds
Accuracy +/- 0.5% +/- 1.5 ppm
(up to 30 ppm)
+/- 5 ppm
(up to 150 ppm)
Power Source One coin type lithium battery (CR 2450)
Approximately 3,000 hours with no alarms or backlighting
(about 1 year of normal use)
Safety Rating CSA classified, “C/US”, as intrinsically safe. Class I, Division 1, Groups A, B, C and D. Class I, Zone 0, Group IIC. Temperature code T4.
Digital LCD with auto back light
& Weight
2.5"(w) x 1.7"(h) x 0.9"(d) / 63.5 mm(w) x 43 mm(h) x 23 mm(d)
2 ounces / 60 grams
& Humidity
-20 ~ 40°C, below 85% RH (non-condensing)
Dimensions &
71.(w) x 84(h) x 29.5(d) mm, 135 g
2.81”(w) x 3.31”(h) x 1.16”(d), 4.76 oz
Features LCD manual back light (automatic lighting during alarm)
STEL, TWA function
Peak hold
Time indication
Watchband, alligator clip, belt clip, and hard hat clip
Warranty 2 years material & workmanship

Specifications subject to change without notice. 

Introduction | Description | Start Up | Operation | Set Alarm Points
Calibration | Maintenance

This video is also available on Youtube and CD (by request)