Unleash your horsepower with the testo 350 for engine testing and tuning

DOWNLOAD THE FREE PDF HERE – to get a better understanding of how proper engine setup can provide better combustion and lower emissions. See what combustion characteristics contribute to detonation problems. See how engine emission develops, and how the testo 350 can be used for both tuning and emission testing.


Engine-specific menus on the testo 350 take the guesswork out of testing. Just select the rich burn or lean burn application. Rich burn engine exhaust, when uncontrolled, can have wide concentration ranges, and both CO and NOX can fluctuate significantly. The patented CO dilution system will automatically set up for optimum testing, and provides greater sensor protection as an extra benefit. Perfect for rich burn engine testing. Learn more by downloading our FREE whitepaper! 

Measures both NO and NO2 for proper engine setup with unsurpassed accuracy

Active gas conditioning is mandatory for EPA and high accuracy testing, and the testo 350's integrated gas conditioning system (thermoelectric cooler with automatic condensate removal pump) delivers dry basis data, as required for most Federal and State reporting.

The powerful pump automatically controls sample flow rate for EPA accuracy.

Teflon lined sample hoses provide the highest level of accuracy. Heavy particulate loading from diesels is easily handled with the sintered filter options. Heated sample lines and the industrial probe option cover all your testing requirements.

Digital sensors provide better response and higher precision.

EPA Engine Testing Regulations

Federal guidelines for testing stationary Reciprocating Internal Combustion Engines (RICE) have made their way into the field. The National Emission Standards for Hazardous Air Pollutants (NESHAP) 40 CFR subpart ZZZZ (aka "quad Z") addresses one type of engine testing criteria. The New Source Performance Standards (NSPS) subpart JJJJ (aka "quad J") addresses yet another set of engines and testing criteria. You can learn more about the standards by reviewing the official EPA Implementation Question and Answer Document.
In both the quad Z and J standards, portable electrochemical (EC) emission analyzers are accepted for testing. Since the late 1990s, Testo's analyzers have demonstrated that both high accuracy and low cost are achievable.

Innovative multi-unit simultaneous testing (quad Z testing solution)

The testo 350 portable emission analyzer greatly reduces the hardware and software needed, and it makes data logging and reviewing easier. Two analyzers can be linked to display catalyst measurements. It's simple, and the cost for this system is also substantially lower than the traditional trailer mounted testing rigs.

It starts by connecting two probes and analyzer boxes to the exhaust stack. Each analyzer is specifically configured for the different gas conditions found in pre- and post-catalyst exhaust gas. Then, both analyzers are connected to the handheld control unit, where the high definition graphic display shows side-by-side measurements. Communication through Testo’s data “BUS” system makes it all possible.

Data collection and interpretation is much easier when you know the actual pre- and post-catalyst measurements in real time. Testo easyEmission can display the measurements of up to 16 analyzer boxes for the ultimate in simultaneous, multi-unit testing.