Industrial smoke tester for diesel engines

Monday, February 2, 2015


Efficient measurement of degree of blackening in diesel engines

It is my pleasure to announce the latest edition to the Testo instruments range. The Testo 338 is a portable instrument which enables quick and simple measurement of smoke from diesel engines. It takes just minutes to start the analyser and make a measurement. It measures Bosch Number, Filter Smoke Number (FSN) and soot concentration in mg/m3.



With the Testo 338 the busy engineer can quickly measure the levels of soot an engine is producing during planned or regular maintenance schedules. Available in two configurations, with or without Bluetooth communications capabilities, the Testo 338 is easy to use, compact, robust, and fast to operate.

It only requires one hand for use and with the touch of a button, and can link to printers via its IRDA port for record retention. After the measurement, soot concentration (mg/m³) as well as the degree of blackening is displayed. This can be altered to display either as an FSN (Filter Smoke Number) or as a Bosch number.


Typical applications for the Testo 338 include:


  • Diesel power or heating engines
  • Ship-owning and ship-building companies on marine engines
  • Industrial engines/turbines
  • Mining and prospecting
  • Construction machines and land-moving vehicles




Modern technology for the highest level of convenience

For most diesel engines, the degree of blackening requires regular measurement. This is used to check whether prescribed limit values are being adhered to, and can also be used to identify problems inside the engine at an early stage.

Up to now, blackening measurements were carried out manually with a hand pump and a comparison table. Automatic measurements were only possible with stationary equipment or large measurement apparatus. Testo have come up with a resolution to this problem.

The testo 338 is a mobile measuring instrument which allows you to measure the degree of blackening both easily and efficiently. It is the first and only mobile measuring instrument which measures the degree of blackening automatically, without any additional analysis. This enables an efficient and professional smoke-count analysis of the engine to be made in a matter of seconds, using one manageable, user friendly piece of equipment.

testo_338It contains an optical, a temperature and a differential pressure sensor. Together, these sensors create a consistent picture of the degree of blackening. The measurement results can be printed out and documented on site. In addition to this, the measurement data can be transferred to the flue gas analyser testo 330 or a computer via Bluetooth and stored there.


All in all the Testo 338 is a truly innovative piece of equipment which incorporates both the quality of a high-end smoke tester and the useability of a portable smoke tester, resulting in a convenient and reliable device.


Technical data
Measuring principle Filter loading
Operating temperature +5 to +45 °C
Memory 200 readings
Data interfaces IrDA/optional Bluetooth
Measurement period < 60s per measurement cycle
Protection class IP 40
Exhaust gas Temperature Single measurements up to +500 °C
Overpressure up to 300 mbar*
Rech. batt. Lithium ion
Battery life Approx. 4 hrs continuous operation
Warranty 2 years
*at higher pressures, a higher measurement inaccuracy occurs


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