Photometers

Photometers are essential instruments for locating and quantifying airborne particulate matter in real time. They are used in many applications, such as filter testing, low-cost air quality sensors, industrial hygiene, and fundamental aerosol research. Designed for applications where rapid response and high sensitivity matter, these instruments provide immediate feedback on particle presence, concentration changes, and emission sources—supporting effective decision-making in industrial, environmental, research, and occupational settings.

Photometers work on the principle of light scattering from aerosol particles. Light scattering is a strong function of particle size, optical properties such as index of refraction, and particle shape, so certain considerations must be made when collecting and analyzing data. However, photometers do not require working fluids or aerosol electrical charge measurements, so they can be suitable for a wide range of uses. TSI’s innovative photometer designs incorporate decades of aerosol instrumentation design experience, so you can be confident in your measurement results, no matter the application.