Met One E-SEQ-FRM: Sequential Reference Method Sampler

US EPA Designated Regulatory Sampling for PM2.5, PM10, and Coarse PM

The Met One E-SEQ-FRM is a high-capacity sequential air sampler designed to meet the strictest regulatory standards for particulate matter monitoring. Engineered as a United States EPA Federal Reference Method (FRM) sampler, it provides the "Gold Standard" gravimetric data required for National Ambient Air Quality Standards (NAAQS) compliance. Unlike single-event samplers that require daily site visits, the E-SEQ-FRM features an automated filter exchange mechanism capable of holding up to 16 filter cassettes, allowing for over two weeks of unattended daily sampling.

Ideally suited for environmental agencies and research institutions, this modular system combines the precision of laboratory-grade gravimetric analysis with the ruggedness required for field deployment. Its active volumetric flow control and temperature-regulated filter storage ensure that every sample remains chemically stable and compliant with EPA strictures until collection.

Key Benefits

• Extended Unattended Operation: With a 16-filter magazine capacity, the E-SEQ-FRM drastically reduces operational costs by minimizing site visits. Operators can schedule up to 16 independent sampling events, making it perfect for remote locations or weekend-free operation.

• Modular & Portable Design: Recognizing the challenges of field installation, Met One engineered the system to be fully modular. No single component (pump box, main unit, or stand) weighs more than 20 kg (45 lb), allowing for easy transport to difficult-to-access monitoring sites without heavy lifting equipment.

• Total Regulatory Compliance: Designated as a Reference Method for PM2.5, PM10, and PM10-2.5, this sampler ensures your data is legally defensible. It features active flow control (maintaining 16.67 LPM) and strict filter temperature maintenance (within ±5°C of ambient) to prevent the volatilization of semi-volatile compounds.

• Flexible Data Management: The intuitive internal Event Manager allows for complex scheduling (e.g., 1-in-3 day or 1-in-6 day sampling). Data retrieval is seamless via RS-232 remote connection or simple USB flash drive export, providing secure digital chains of custody.

Technical Overview

The E-SEQ-FRM operates on the principle of Gravimetric Sampling. Ambient air is drawn at a constant, volumetrically controlled flow rate of 16.67 LPM through a specific size-selective inlet (PM10 or PM2.5). The particulate matter is deposited onto 47 mm filter media (Teflon or Quartz) which is pre- and post-weighed in a laboratory to determine mass concentration.

Advanced Filter Handling:

The instrument uses a precision-engineered transport mechanism to move filters from the supply magazine to the sampling position and then to the storage magazine. Crucially, the internal storage environment is ventilated and temperature-controlled to preserve sample integrity, adhering to US EPA requirements for preventing thermal degradation of collected samples.

System Architecture:

• Inlets: Compatible with standard EPA PM10 inlets and PM2.5 VSCC (Very Sharp Cut Cyclone) or WINS impactors.

• Flow Control: Active mass flow feedback loop corrects for temperature and pressure in real-time.

• Electronics: Microprocessor-controlled with a weather-resistant touchscreen interface for easy programming and status checks.

Typical Use Cases

• National Air Quality Networks: Primary compliance monitoring for government agencies reporting to the US EPA, EU, or local environmental bodies.

• Background Station Monitoring: Long-term deployment in remote areas where daily operator access is impossible or cost-prohibitive.

• Source Apportionment Studies: Collecting physical samples for subsequent chemical analysis (ions, metals, carbon) to identify pollution sources.

• Coarse Particulate Monitoring: By collocating two units (one PM2.5, one PM10), the system provides precise PM10-2.5 (Coarse) data, a critical parameter for dust and industrial emission tracking.

Why Choose This Sampler?

While real-time optical monitors provide speed, they cannot replace the legal authority of the Reference Method. The Met One E-SEQ-FRM bridges the gap between precision and practicality. It eliminates the logistical nightmare of daily manual filter changes associated with older FRM samplers while maintaining the highest designation level possible. Whether for legal enforcement, academic research, or verifying the calibration of continuous monitors, the E-SEQ-FRM delivers the undeniable accuracy of physical mass measurement.

Specifications

• Measured Components:

  Particulate Matter Mass (PM2.5, PM10, PM10-2.5/Coarse).

  Note: The instrument collects the sample; the laboratory measures the mass.

• Applications:

  Regulatory compliance (NAAQS), reference method monitoring, air quality research, chemical speciation sampling.

• Certifications:

  • US EPA PM2.5 FRM: RFPS-0717-245

  • US EPA PM10 FRM: RFPS-0717-246

  • US EPA PM10-2.5 FRM: RFPS-0717-247

• Measurement Principle:

  Sequential Filter-Based Gravimetric Sampling (Active Volumetric Flow Control).