Particulate Matter (PM / PM10) Source Testing for CARB Compliance

At REM, we provide comprehensive source testing services to support California Air Resources Board (CARB) compliance, including precise measurement and analysis of particulate matter (PM) and PM10 emissions. These pollutants are closely regulated due to their impact on air quality and public health, and accurate quantification is critical for permitting, reporting, and operational compliance.

What We Measure

Particulate matter (PM) refers to solid particles and liquid droplets emitted from industrial processes. PM10 represents particles with an aerodynamic diameter of 10 microns or less—small enough to be inhaled and regulated under CARB and local air district rules.

Our testing programs are designed to quantify:

• Total filterable particulate matter (PM)

• PM10 (particles ≤10 microns)

• Where required, condensable particulate matter (CPM) to provide a complete emissions profile

How REM Conducts PM / PM10 Testing

REM follows U.S. EPA reference methods and CARB-approved protocols to ensure defensible, audit-ready results.

1. Pre-Test Planning & Compliance Alignment

We begin by reviewing your permit conditions, applicable CARB regulations, and local air district requirements. This ensures:

• Selection of the correct test methods (e.g., EPA Methods 5, 201A, 202)

• Proper test locations and run conditions

• Alignment with reporting thresholds and compliance limits

2. Isokinetic Stack Sampling

PM and PM10 testing is conducted using isokinetic sampling, a technique that ensures the velocity of gas entering the sampling probe matches the velocity of the stack gas stream. This is critical to collecting a representative sample.

• A heated probe extracts gas from the stack

• Particles are captured on pre-weighed filters

• Sampling trains are configured specifically for PM or PM10 fractions

For PM10, we incorporate a size-selective cyclone or impactor to separate particles based on aerodynamic diameter before collection.

3. Moisture and Gas Conditioning

Stack gases often contain moisture and volatile compounds. Our systems:

• Control temperature to prevent condensation during sampling

• Separate and measure moisture content

• Ensure particulate capture is not biased by phase changes

4. Gravimetric Analysis

Collected samples are transported under strict chain-of-custody procedures and analyzed gravimetrically:

• Filters are conditioned in a controlled environment

• Pre- and post-test weights are measured with high-precision balances

• The mass difference determines particulate concentration

For condensable PM (if required), impinger solutions are analyzed to quantify particles formed after cooling.

5. Data Reduction & Emissions Calculations

We convert raw measurements into standardized emissions data, including:

• Grains per dry standard cubic foot (gr/dscf)

• Pounds per hour (lb/hr)

• Mass emission rates aligned with permit limits

All calculations follow EPA and CARB guidelines to ensure regulatory acceptance.

6. Reporting & Compliance Documentation

REM delivers clear, regulator-ready reports that include:

• Test methodologies and conditions

• Calibration and quality assurance documentation

• Detailed results and compliance determinations

Our reports are structured to meet CARB and local air district submittal requirements, minimizing review delays and follow-up requests.

Why It Matters

Accurate PM and PM10 testing is not just a regulatory checkbox—it directly impacts:

• Permit compliance and operational continuity

• Community air quality and environmental responsibility

• Risk mitigation during inspections or audits

REM’s rigorous methodology, experienced field teams, and defensible data ensure that your emissions profile is both accurate and compliant.