The sensing element of the instrument is an electrochemical cell. The cell is a four-electrode type, which contains a working and an active auxiliary electrode. The signal from the auxiliary electrode is used for temperature compensation and to improve the selectivity of the entire sensor. The sensor response is linear with the concentration of the target gas in air.

Environmental Sensors Co.'s Carbon Monoxide Meter is a portable desktop instrument that measures carbon monoxide concentration in a range of 0-1000 ppm and a resolution of 0.1 ppm.

The instrument makes it possible to monitor carbon monxide vapor in air. The insturment has an LCD display giving concentrations in ppm every 10 seconds, a low battery indicator, and an audible alarm that can be set at any level from 0-1000 ppm.

With the touch of a button, the meter displays STEL (average of every 15 min.), TWA (8 hour average) and Peak.

The internal pump makes it possible to sample from hard-to-reach areas or confined spaces by attaching a flexible tube to the meter.