Plain-language explanations of the measurements, sensors and numbers behind environmental monitoring.
Combustible on a detector means the gas has a lower explosive limit and will oxidise on a hot sensor, which leaves out every gas that cannot burn and every hazard that arrives below the explosive limit.
Read Article→Coverage follows chemistry, so the check runs from what the two refrigerants are made of, through the sensing technology, to the two questions a gas list never answers.
Read Article→A2L is a safety classification rather than a chemical family, and the gap in most detector listings is not the sensing chemistry but whether the instrument is built for a flammable atmosphere and reports against the flammability limit.
Read Article→There are four workable ways to get a current figure off a busbar that no clamp will encircle, and each of them trades a different kind of error for the access it buys you.
Read Article→A Hall element reads the magnetic field itself and therefore reads direct current, while a Rogowski coil reads the rate at which that field changes and therefore wins on range, size and speed instead.
Read Article→A Rogowski coil produces an output only while the current inside it is changing, so a settled direct current gives it nothing to respond to and no amount of gain or firmware can recover the reading.
Read Article→A Rogowski coil is an air cored winding whose output follows the rate of change of current, so an integrator rebuilds the waveform, saturation never occurs and a steady direct current produces nothing at all.
Read Article→Every infrared monitor drifts as its source ages and its optics foul, so the zero has to be re established either by an automatic baseline routine or by a fresh air calibration you run deliberately.
Read Article→The letter e stands for equivalent, and an eCO2 figure is calculated from a volatile organic compound sensor using an assumed ratio rather than measured from the gas itself.
Read Article→A monitor that jumps when you spray cleaner is responding to solvent vapour on a heated film rather than to carbon dioxide, and the shape of the rise and fall identifies which sensor is inside.
Read Article→An infrared monitor counts carbon dioxide directly by absorption while a metal oxide monitor infers a figure from unrelated gases, so a gap between the two is the expected result rather than a fault.
Read Article→A worn out gas sensor keeps displaying a comfortable number, so an end of life warning is often the only thing separating a working detector from a decorative one.
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