Gas Monitors & Sensors
The BW Technologies GA24XT-H GasAlertClip 2-year H2S detector is a handheld, single-gas detector that uses an
electrochemical cell sensor to monitor hydrogen sulfide (H2S) levels consistently for up to two years without requiring
calibration, recharging, or battery replacement, and that has audio, visual, and vibration alarms, which alert
simultaneously when H2S reaches the preset low and high alarm levels. The detector has an alphanumeric LCD screen that
can be adjusted by the user to show the gas type monitored, the two alarm set-points, the alarm level (low or high), the
maximum gas level recorded within the previous 24-hour period, the time elapsed since reaching that maximum level, and
the detector life remaining, as well as whether or not a self-test is required. It is operated and adjusted with a
single push button. This detector is used to indicate potentially harmful levels of H2S gas naturally occurring in the
environment; in a variety of occupational settings such as petroleum refineries, tanneries, sewage treatment facilities,
and paper mills; and in other personal safety, educational, and ambient monitoring applications.
This detector is factory-set to alert a low-alarm condition when the level of H2S reaches 10 parts per million (ppm),
and a high-alarm condition when H2S reaches 15 ppm. In low-alarm conditions, the audible alarm beeps once, the visual
alarm flashes, and the unit vibrates once per second. In high-alarm conditions, the audible alarm beeps twice, the
visual alarm flashes two times, and the unit vibrates twice per second. The three bright, wide-angle visual alarm bars
and the built-in vibration alarm help alert the user to potentially dangerous levels of H2S in high-noise conditions.
The alarm deactivates when the gas level returns to an acceptable range. Once the gas exposure alarm initiates, the
detector records the maximum gas exposure and the time since reaching that maximum gas exposure for up to 24 hours. The
detector logs and retains data of the 10 most recent gas exposure events, which it can transmit via built-in infrared
sensor to a thermal printer (sold separately), or via an infrared Datalink USB adapter to a personal computer (both sold
To ensure performance, the detector tests its built-in lithium battery automatically every two hours, and the LCD
prompts the user daily to initiate a full-function self-test. The self-test verifies the integrity of the battery,
sensor, and circuitry. The detector also features an automatic shutdown mode for additional safety, which activates
after five consecutive battery test failures, three consecutive self-test failures, or when the detector has reached the
end of its two-year life.
This detector comes with a back-mounted alligator clip to allow the unit to be worn on a belt, waistband, or lapel, and
a concussion-resistant boot to help protect it against damage. It is water resistant, and is compatible with the BW
Technologies MicroDock II automatic test system (sold separately). It has a European Conformity (CE) and ATEX
certification in accordance with Directive 94/9/EC concerning equipment or protective systems intended for use in
potentially explosive atmospheres, and it meets Underwriters Laboratory (UL) 913 for an Intrinsically Safe Apparatus and
Associated Apparatus for Use in Class I, II, and III, Division I, Hazardous (Classified) Locations.
0 to 100 ppm
-40 to +122 degree F/-40 to +50 degree C
5% to 95% RH (noncondensing)
Audible Alarm Sound Level
3.2 x 2.0 x 1.1 inches/2.8 x 5.0 x 8.1 cm (H x W x D)*
2.7 oz./76 g
*H is height, the vertical distance from the lowest to highest point; W is width, the horizontal distance from left to
right; D is depth, the horizontal distance from front to back.
A gas detector is a safety device that detects and monitors various toxic, combustible, and flammable gasses in an
area, and which can also register a decrease in ambient oxygen. Gas detectors can be portable or stationary, and are
typically classified by their detection methods, which include catalytic, electro-chemical, point infrared, open-path
infrared, semiconductor, thermal path conductor, and paper tape detection. Gas detectors are first calibrated to known
gasses that serve as a reference points. Their sensors can then be used to measure ambient gas concentrations in
comparison to the calibration gasses. When gas concentrations exceed a pre-set limit, an alarm or signal is triggered,
alerting the user to potential danger. Pre-set limits often include a low-alarm level, indicating a gas concentration
that poses a moderate danger; a high-alarm level, indicating a gas concentration that poses a large danger; a short-term
exposure limit (STEL), the maximum gas concentration to which workers can be exposed continuously for a short period of
time without serious risk of harm, and time-weighted average (TWA) limit, the maximum average exposure personnel can
experience over the course of an eight-hour work shift without serious risk of harm. Most gas detectors also feature LCD
screens that provide a variety of information including gasses detected and their concentrations, pre-set exposure
limits, and battery level.
Gas detectors have a variety of industrial and governmental applications, such as in fire and rescue, mining,
construction, petroleum refineries, tanneries, sewage treatment facilities, and paper mills. Portable gas detectors are
typically used to monitor the air around personnel, are worn on clothing or on belts or harnesses, and are powered with
rechargeable or disposable batteries. They generally require periodic calibration, testing, and battery recharging or
replacement, although some fixed-life detectors are designed to perform for a number of years without calibration or
battery replacement before being discarded. Stationary gas detectors are typically powered electrically and mounted near
the process area of a plant or control room. They also require periodic service, testing, and calibration.
BW Technologies by Honeywell manufactures and distributes portable and fixed gas monitoring equipment for use in a wide
range of industries. The company, founded in 1987, is based in Canada in Calgary, Alberta.