AM307 vs AM308L: which Milesight air quality sensor do you need?

Short answer: The AM308L is the one that measures particulates — PM2.5 and PM10, 0 to 1000 µg/m³ by laser scattering — but it has no display at all. The Milesight AM307 carries the 4.2-inch black-and-white E-Ink screen and no particulate sensor. Everything else is specified identically on both: temperature, humidity, NDIR CO2 at 400 to 5000 ppm, TVOC, light, barometric pressure and PIR occupancy. The catch in AM307 vs AM308L is battery life — around three years on the AM307 against around 1.3 years on the AM308L, same batteries, same 10-minute reporting interval.

AM307 vs AM308L: which one do I actually need?

Choose the AM307 if the room needs to see its own air. Anywhere a person makes a decision from the reading — a meeting room people walk out of, a classroom, a reception desk, a ward corridor — the 4.2-inch E-Ink screen and the traffic-light indicator do the job before anyone opens a dashboard. It is also the one to fit where a battery change is disruptive: three years at a 10-minute interval and 25°C, against around 1.3 years for the particulate model.

Choose the AM308L if the number that matters is dust and nobody is standing in front of the device. It adds PM2.5 and PM10 over the AM307’s sensor set and drops the screen, so it suits ceiling height, plant rooms, print and workshop areas, or a building-wide LoRaWAN estate where every reading lands in software anyway. Budget for shorter battery intervals or run it on the 5 V / 1 A USB-C supply, which both models accept.

Is the AM308L’s PM2.5 reading a dust-monitoring instrument?

No, and this is where most of the confusion sits. The AM308L is an indoor ambience sensor, not an occupational exposure instrument. Its particulate figures come from a laser-scattering cell rated 0 to 1000 µg/m³, with ±10 µg/m³ up to 100 µg/m³ and ±10% above that; the listed approvals are CE, CE (RED), FCC, ISED and RoHS. Nothing in the specification claims gravimetric equivalence or fitness for a COSHH assessment. Treat it as a trend and threshold device — it will tell you a workshop extraction fan failed at 3 a.m., and it will not stand up as the reading in a dust exposure report.

One more disambiguation: the AM307 is not a de-specified AM308L. It is the same 100.8 × 114 × 22 mm body with the screen fitted and the particulate cell absent. The AM308 — screen and particulates — is a third variant, listed here alongside the AM307.

Where the two are the same

On the shared sensors the datasheets do not distinguish them. CO2 is NDIR, 400 to 5000 ppm, ±(30 ppm + 3% of reading), 1 ppm resolution on both. Temperature is −20°C to 60°C at ±0.2°C above freezing (the AM308L sheet adds a ±0.3°C figure below 0°C), humidity 0 to 100% RH at ±2% RH, TVOC a 1.00 to 5.00 IAQ rating, pressure 260 to 1260 hPa at ±0.5 hPa, light 0 to 60000 Lux reported as six levels, and PIR occupancy 80° horizontal by 55° vertical to 5 m. Both are IP30 indoor units, both hold 18,000 records with retransmission, both configure by NFC or USB-C, and both are Class A LoRaWAN on EU868, the UK band. If your shortlist turned on CO2 accuracy or radio performance, the specification will not decide it for you — the screen, the particulates and the battery interval will.

Milesight AM307 / AM308 / AM319 Indoor Ambience Monitoring Sensor – AM307-868M

AM307-868M

£224.45 ex VAT (£269.34 inc. VAT)

View the AM307-868M

Milesight AM308L Indoor Ambience Monitoring Sensor

AM308L-868M

£239.41 ex VAT (£287.29 inc. VAT)

DisplayAM308L: Not Support (AM307 and AM308 use a 4.2-inch black & white E-Ink screen)

View the AM308L-868M