Specifications
71
GM 12A/12B Portable CO
2
Meter
FEATURES / BENEFITS
Excellent long term stability
High accuracy
Operates in demanding environments
Low cost
Operates over full relative humidity range
Digital display and voltage output
HIGH PERFORMANCE/LOW COST
MEASUREMENT
Vaisalas GM 12 meter incorporates a single wave-
length non-dispersive infrared (NDIR) gas sensor for
CO
2
-specific sensing. Other gases, including water
vapor, do not affect its performance, nor is it ad-
versely affected by high concentrations of CO
2
. The
sensor is accurate and stable, and has a short warm-
up time, which is particularly important in spot
measurements.
VERSATILE AND EASY TO USE
The portable GM 12 is used in a wide variety of
applications including environmental, process and
ventilation survey and monitoring. It is available in
two measurement ranges: 0 to 3000 ppm (GM 12A)
and 0 to 3% carbon dioxide (GM 12B).
The GM 12 comes with an analog output and a digital
display. Operated via a membrane keypad, the GM
12 has a user-selectable alarm level with audible and
visual signals. The audible alarm and red light are
activated when the measured gas concentrate
exceeds the desired level. CO
2
concentration is
shown on the clear 4 digit LCD. A voltage output is
also available.
The meters low flow indicator shows if the filter
becomes dirty or the pump stops operating. The gas
inlet nozzle is situated on the front panel of the meter
to allow easy access for periodical replacement of the
particle filter.
The GM 12 has a standard battery life of 12 hours.
The rechargeable batteries are contained in a
detachable section of the meter housing. A simple
key function allows the user to check remaining
battery life.
The meter housing is rated NEMA 4 for use in the
most rigorous environments. It comes in a rugged
weatherproof carrying case, which includes a battery.
There is also enough space for other accessories.
GM 12A/12B Portable CO
2
Meter