Sample Flow

Sample flow is the rate at which an instrument draws air through its inlet, and on this platform it is an instrument's own operating reading rather than a property of the air. It comes from the particulate instruments that pull a measured volume through a filter: the concentration they report depends on how much air passed through, so the flow is what makes the result trustworthy.

Two instrument families in the sensor catalog report it. The Thermo Scientific Partisol reference-method samplers run at the 16.67 L/min reference flow and collect PM2.5 or PM10 on filters that are weighed afterward in the laboratory, where the mass is divided by the sampled volume. Over the data link, the sampler therefore reports its operating telemetry (sample flow, ambient temperature, and barometric pressure) rather than a live concentration. The AethLabs microAeth aethalometers log their sample flow (in mL/min) alongside black carbon, temperature, and humidity; the wearable MA200's internal pump runs at 50–170 mL/min and the MA350 reaches 170 mL/min.

Each instrument measures its own flow internally and reports it with the rest of its record; nothing extra is fitted. A Partisol connects to a Thiamis gateway over RS-232 using Thermo's C-Link protocol, and a microAeth over USB, so the flow lands in Environet next to the instrument's other readings with the same alerts and history.