Industrial process testing can be difficult due to the extreme variations in testing conditions: high flue gas concentrations, heavy particulate loading, and scorching temperatures. For your industrial process testing, you can depend on the flexible, rugged, and reliable Testo 350.

You can use the 350 for:

  • Energy balancing & combustion optimization

  • Efficiency determination

  • Combustion process measurements

  • Flue gas velocity and mass flow measurements

  • Semi-continuous emission monitoring

  • SCR tuning

  • CEMS confirmation

Configure the 350 with only the O2 and CO sensor to determine combustion stability, or use it to trace O2 leakage within a kiln. Use the CO measurement it to pinpoint a bad burner.  With the optional dilution upgrade, the analyzer can measure up to 400,000 ppm, so sensor over-range is no longer a concern.



Whether your combustion process is out of control, or you simply need to measure very high concentrations, the built-in dilution system on the 350 ensures accurate measurements while protecting the sensors from damage. Simply swap the gas sensor to the dilution channel to expand the sensor range (up to 40x), or you can activate the “overall dilution mode” to expand the range of all toxic sensors to 5 times their normal operation range. The display values are corrected for the selected dilution factor, eliminating the need for calculations.



The 350 has many design features that also permit “semi-stationary” monitoring. With massive memory and the ability to perform automatic testing programs, the analyzer can log combustion values for more than a month. Download stored readings from memory using easyEmission software, or use the software to control and capture data in real time. Additionally, the 350 can also be operated through user-developed software. Use the Testo Tool Software Kit to develop your own testing and data logging programs, allowing full integration into your data acquisition system.

Advanced features for semi-continuous monitoring include:

  • Automatic sample gas conditioning (peltier-type) with hose bib to empty condensate

  • Trigger switch to turn on testing program (activate with a falling/rising signal)

  • Six channel analog output box can be looped to provide (user selected) 4-20 mA output

  • DevIce is wall-mountable


Industrial Process Probes from Testo are designed specifically to handle the unique challenges encountered during process testing, with features that include:

  • Modular design for tool-free probe changes

  • Integrated thermocouple

  • Hi-temp probes for applications up to 1832°F

  • Teflon-lined hoses to ensure sample integrity

  • Optional sintered filter for heavy 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.