--- title: "Sample Flow Sensors & Monitoring | Aethair" description: "Sample flow is the rate an instrument draws air through its inlet. How Partisol samplers and microAeth aethalometers report it to Environet." url: https://aethair.io/parameters/sample_flow/ --- Measurements · Particulate Matter # Sample Flow Also known as air flow, sample flow rate 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. [Schedule a call](https://calendly.com/d/ctdd-mkr-v9v/aethair-demo-website) [Configure Sample Flow Monitoring](https://aethair.io/build/?params=sample_flow) At a glance L/min Particulate Matter 1 way to measure it - **Thiamis** 2 external instruments What it is ## What is 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](https://aethair.io/sensors/thermo-scientific-particulate-dust-monitors/) 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](https://aethair.io/sensors/aethlabs-specialty-air-analyzers/) 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. How it is measured ## How Sample Flow Is Measured 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](https://aethair.io/products/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. An instrument on Thiamis 2 A third-party instrument connected to a Thiamis gateway, reporting into the same Environet account. ### Placing sample flow in a monitoring record Because it describes the sampler and not the site, sample flow belongs in the same record as the measurement it qualifies. Logged continuously, it shows whether a filter sample was drawn at its reference rate for the whole run, or when the flow departed from it. ### Every device and option that measures Sample Flow 2 | Device / option | Type | Base platform | Measures | | - | - | - | - | | [AethLabs](https://aethair.io/sensors/aethlabs-specialty-air-analyzers/) · MA200, MA300, MA350… | Specialty Air Analyzers | Thiamis | Sample Flow [Black Carbon](https://aethair.io/parameters/black_carbon/) [Dew Point](https://aethair.io/parameters/dew_point/) [Relative Humidity](https://aethair.io/parameters/humidity/) [Air Temperature](https://aethair.io/parameters/temperature/) | | [Thermo Scientific](https://aethair.io/sensors/thermo-scientific-particulate-dust-monitors/) · Partisol 2025i, Partisol 2025i-D, Partisol 2000i… | Particulate & Dust Monitors | Thiamis | Sample Flow [Barometric Pressure](https://aethair.io/parameters/pressure/) [Air Temperature](https://aethair.io/parameters/temperature/) [Wind Direction](https://aethair.io/parameters/wind_direction/) [Wind Speed](https://aethair.io/parameters/wind_speed/) | [Configure Sample Flow Monitoring](https://aethair.io/build/?params=sample_flow) Related ## More in Particulate Matter [Total PM / Mass Conc.](https://aethair.io/parameters/pm_total/) [PM2.5](https://aethair.io/parameters/pm2_5/) [PM10](https://aethair.io/parameters/pm10/) [PM1](https://aethair.io/parameters/pm1/) [PM4 (Respirable)](https://aethair.io/parameters/pm4/) [Particle Count (by size)](https://aethair.io/parameters/particle_count/) [Respirable Crystalline Silica](https://aethair.io/parameters/silica/) [Black Carbon](https://aethair.io/parameters/black_carbon/) Questions ## Sample Flow FAQ Which instruments report sample flow? The Thermo Scientific Partisol reference-method samplers (2025i, 2025i-D, 2000i, and 2000i-D) and the AethLabs microAeth aethalometers (MA200, MA300, MA350, and MA600). Why does a Partisol report flow but not PM2.5? Its PM2.5 and PM10 are determined in the laboratory by weighing the exposed filter and dividing the mass by the sampled volume. The live data link therefore carries the sampler's operating telemetry (sample flow, ambient temperature, and barometric pressure) rather than a real-time concentration. What flow does a Partisol sample at? The 16.67 L/min reference flow.