Lawrence Berkeley National Laboratory

Residential wood heater certification testing relies on time-integrated gravimetric filters that obscure the transient particulate matter (PM) generation events central to heater development. Continuous PM instruments could support the next-generation wood heater development, but most are designed for ambient air and struggle under the high concentrations, transient conditions, and variable aerosol properties of wood combustion. This study evaluated five continuous PM instruments spanning light scattering (TSI DustTrak II 8530, Thermo MIE pDR-1500, Particles Plus 8306), inertial mass (Thermo Scientific 1405-D TEOM), and triboelectric charge (Sintrol S203) against gravimetric filters and size-resolved reference concentrations across three heater types and two operating phases. No single instrument performed well across all conditions. The DustTrak II and pDR-1500 demonstrated the most consistent temporal tracking ( r ≥ 0.87 and r ≥ 0.79 , respectively). However, both substantially overestimated integrated PM mass during cordwood combustion, requiring gravimetric correction for quantitative use. The TEOM performed most closely to the gravimetric reference during high-burn pellet tests but exhibited sustained negative cumulative mass during cordwood tests. The Particles Plus and Sintrol showed the weakest overall performance. These results support the continued advancement of residential wood heater technologies by identifying conditions under which each instrument provides reliable PM data and those where it is prone to failure. Furthermore, these findings can inform instrument selection for laboratory product development and field verification studies.