Met One E-BAM & ES-642

No. The E-BAM is a single beta-attenuation gauge that measures one size fraction at a time, set by the installed inlet. Each AutoMet data record carries a Type flag for the fitted inlet, and the Thiamis integration routes the concentration to the PM2.5 channel or the PM10 channel accordingly. Change the inlet cyclone to switch fraction. TSP and PM1 inlets are also offered, but the integration reports them on the PM2.5/PM10 channels.

Each minute the E-BAM reports two concentrations for the active size fraction: a real-time value (ConcRT) from the selectable 8–60-minute moving average, and the standard 1-hour value (ConcHr). Both are in mg/m³ and both are ingested by the platform.

Ambient air temperature and relative humidity come standard from the Model 597A ambient sensor and keep the 16.7 L/min sample at true volumetric flow. Wind speed and wind direction are reported only when the optional wind sensor is fitted; without it the platform suppresses the placeholder values. The 597A also senses barometric pressure for internal flow correction, but pressure is not transmitted in the serial data record.

The E-BAM draws a measured 16.7 L/min sample onto a glass-fiber filter tape and determines the collected mass from the attenuation of carbon-14 beta particles, a direct gravimetric-equivalent method with accuracy and precision consistent with US EPA Class III PM2.5/PM10 criteria. Unlike a nephelometer such as the ES-642 it needs no site-specific scattering correction and, sampling under true ambient conditions, captures semi-volatile nitrates and organics.

Both are portable 16.7 L/min beta-attenuation monitors that share the Model 597A ambient sensor and true-volumetric-flow design. The classic E-BAM is a Class III near-reference instrument that runs on AC or DC (battery/solar) and is inlet-selectable for PM2.5 or PM10. The E-BAM Plus is the upgraded, mains-powered version with an external AC pump, added filter temperature/RH/pressure sensors, and a lower detection limit, and carries a U.S.-EPA Federal Equivalent Method designation for PM10 (EQPM-1215-226); it ships with a PM10 inlet and takes an optional PM2.5 cyclone or TSP inlet. Support for the E-BAM Plus in the platform integration is not yet verified.

The ES-642 reports a single mass-concentration channel; the fitted inlet sets the size fraction. It ships with a TSP inlet and accepts optional PM10, PM2.5, or PM1 sharp-cut cyclones. Because the nephelometer outputs one mass value regardless of the cyclone, the platform records it as total mass concentration and the installed cyclone defines which fraction that represents.

Only the real-time mass concentration (the instrument's ME reading) plus its status and error flags, polled once a minute; the model, serial number, and firmware version are read once at start-up. The onboard ambient-temperature, barometric-pressure, and sample-RH sensors drive the instrument's own flow control, intake heater, and auto-zero but are not transmitted to the platform.

The ES-642 is an optical nephelometer: it infers mass from forward light scatter, calibrated to a traceable 0.6-micron PSL standard, which makes it fast, low-maintenance, and sensitive from 0.1 to 100 microns (optimal 0.5–10). It is an indicative monitor rather than a reference method; regulatory-grade mass measurement uses a gravimetric or beta instrument such as the E-BAM, and the ES-642 is often site-calibrated against one.

A built-in 10-watt intake heater is regulated to hold the sample below a relative-humidity set point, drying the aerosol before it reaches the optics so condensation and hygroscopic growth do not inflate the reading. An automatic zero-calibration routine runs every hour (programmable from 1 to 999 minutes) to correct optical drift.