• Draft and pressure measurement
  • Ambient CO measurement
  • RESNET certified combustion analyzer
  • Differential temperature
  • High-definition graphic display
  • Sensor diagnostics & monitoring
  • Ultra-rugged housing
  • 30 second start up
  • Hands-free operation
  • Easy to see and replace filters
  • Store up to 500 tests
  • Hardened cam-lock fittings
  • Simple icon navigation
  • Quick drain condensate trap


The Testo 320 Combustion Analyzer makes combustion analysis easier to perform, easier to control, and easier to understand. The 320 is designed for the job site and for the contractor that expects more. Use it for basic testing and tuning of all types of boilers, heater or furnaces. Use it to set up and commission more complex multi-stage, or modulating heating systems. Combustion analysis, draft, temperature, pressure, combustion efficiency and a host of other calculations and functions - all shown in vivid color. With simple icon navigation, you soon realize it will do more for HVAC testing. The 320 is a RESNET certified combustion analyzer.

With the testo 320 you gain more testing flexibility giving you more customer opportunities and greater profit potential. It provides all the parameters listed, plus the capabilities shows in the following pages.

The testo 320 gives you a wider measurement range that lets you test not only controlled or normal combustion applications but those that have problems. With a CO measurement range up to 4000 ppm (or optional 8000 ppm) you can test more combustion appliances.

The testo 320 eliminates the guess work and provides accurate readings. Integrated NOx filters assure you of the highest CO measurement accuracy, unlike other analyzers that add the NOx concentration to the CO measurement displayed. Whether you are measuring combustion, air free, or ambient CO – you need to make the decision on a correct measurement.