Any experienced field technician knows all too well the difficulty involved in getting an accurate measurement from a burner: unexpected bursts of CO damage equipment, there's no room to maneuver, and climbing on the stack is both exhausting and dangerous. 

Testo relied heavily on feedback from field users when they designed the 350, and the result is a powerful and portable analyzer with innovative features, including:

  • Built-in dilution system automatically detects bursts of CO and begins mixing fresh air, preventing costly equipment damage

  • Measures true NOx (NO and NO2) for proper burner setup and pinpoint accuracy

  • The compact design of the 350 facilitates easy one-handed carry, and is ideal for working on small platforms and confined spaces

  • Bluetooth analyzer box allows for remote operation of all features (including purge) from up to 300 ft away, using either the 350 control unit or your Android smartphone/tablet

  • Self-zeroing pressure sensor allows for long term mass emission flow measurements

  • Optional pitot tube measures velocity and mass flow for easy lbs/hour reporting

Measuring Capabilities

O2 NO Hydrocarbons
CO NOlow Velocity
COlow NO2 Pressure
NOx SO2 Temperature
CO2 H2S Dilution

Fast measurement of O2, CO, NO, and NO2, along with automatic calculations (CO2, efficiency, and excess air) mean faster boiler and burner tuning; and with long-range Bluetooth built-in, testing no longer entails working in uncomfortable heat and climbing ladders to dangerous platforms.

Make the switch to the Testo 350, and take the hassle out of burner testing. 


Boiler/Burner Probes from Testo are designed specifically to handle the unique challenges of tuning a boiler, with features that include:

  • Modular design for tool-free probe changes

  • Integrated thermocouple

  • Optional hi-temp probes for applications up to 1832°F

  • Teflon-lined hoses to ensure sample integrity

  • Optional sintered filter for heavy coal particulate loads

  • Optional pitot tube to measure velocity and flow

  • 9 ft. hose extensions available (5 extensions maximum)



Take the guesswork out of your emissions testing with the Testo 350. Built-in boiler-specific testing programs automatically select the right settings to test most common fuels; and with storage for up to 20 user-defined fuels, you can fine-tune your testing program to fit your individual needs. 

In addition, the 350 can be used for high-accuracy and EPA Compliance testing with the optional Active Gas Conditioning system, which uses an onboard peltier chiller with automatic condensate removal to produce a dry sample, giving the highest degree of accuracy.



Innovative technology has long been a signature of German manufacturers, and even among all the advanced features of the 350, this one is particularly revolutionary: control your analyzer with your Android smartphone/tablet using the free Testo app from Google Play.

This game-changing feature, exclusively from Testo, allows you to control all functions of your analyzer, including starting/stopping readings, purging gas, and changing testing parameters, all from your phone, and from up to 300 feet away.

You can also view real-time measuring data in either numerical or graphical form, and save the data to your phone. Even email readings direct from the app - no more looking for measurement printouts. The future is here - work smarter with Testo.



Simultaneous catalyst measurements used to mean using an expensive and complex trailer-mounted testing rig. Not anymore. With the 350, multiple analyzers can be linked together to read catalyst measurements.

Simply connect two or more (up to 16) probes and analyzer boxes to the exhaust stack (each analyzer can be configured to test either pre- or post-catalyst exhaust gas). Then just connect the analyzer boxes using a data cable, and you can read real-time measurements from each box on a single hand-held control unit. Even display two measurements side-by-side. And when you finish testing, use Testo easyEmission software to analyze and export your readings.