2B Technologies POM

By UV absorption at 254 nm. A mercury lamp shines through a folded 'U'-shaped optical cell and ozone is quantified from the light it absorbs (Beer-Lambert law). Folding the path lets the handheld reach the same effective path length as 2B Technologies' benchtop 106-L, 202, and 205 ozone monitors.

0 to 0.5 ppm ozone at 0.1 ppb resolution. The detection limit is 3.0 ppb in the standard 10-second mode with default adaptive filtering, and precision/accuracy is the greater of 1.5 ppb or 2% of reading. The upper limit was reduced to 0.5 ppm in the current manual revision; older documentation quoting a 10 ppm range is superseded.

They are the optical-cell temperature (in Kelvin) and cell pressure (in Torr) measured inside the instrument. The UV-absorption calculation needs both to convert absorbance into an ozone concentration, so the POM streams them alongside every ozone reading. They are internal instrument conditions, not ambient weather values.

Yes. It is designated a US-EPA Federal Equivalent Method for ozone, EQOA-0815-227.

The driver reads the POM's comma-separated data line over serial at 19200 baud and surfaces ozone, cell temperature, and cell pressure (the first three fields). The built-in GPS logs latitude and longitude with each reading on the device itself, but those coordinates are not ingested as cataloged measurements.