Master the leak

Ideal for steady state, transient and dynamic blow by measurement.


Emission legislation for new combustion engines today and in the future is becoming more and more stringent, therefore engine testing will become even more complex. This also means that the requirements for crankcase ventilation systems will continue to increase. To tackle these challenges, we offer the AVL Blow by Meter™ – an indispensable instrument with a unique performance. It is designed for use in a broad range of applications, from small single cylinder combustion engines to marine diesel aggregates. This innovative and flexible device has the widest measurement range on the market and can fit seamlessly into different engine applications. 

The AVL BLOW BY METER measures the leak gas which occurs between the gaps around pistons, piston rings and valve guides. These gases enter the crankcase and leak via the crankcase breather. The volume of blow by gas has proven to be a sensitive indicator of the state of the piston rings, pistons, and cylinder walls. It is a valuable tool in both engines under development and in engines out of production and already in use.
The necessity of continuous measurement of the blow by flow to monitor the engine condition make the AVL BLOW BY METER an indispensable instrument for engine testing.

Blow by Meter

AVL BLOW BY METER – The proven industry reference

This innovative and flexible device has the widest measurement range on the market and can fit seamlessly into different engine applications. Its user interface is fully embedded into our PUMA automation system and delivers intuitive operation along with quick and easy parametrization. Our BLOW BY METER also impresses with a fast testbed setup and easy integration into any automation system via CAN Bus, analogue or ethernet interface.
On the basis of the interchangeable measurement ranges between 0,2 and 2,400 l/min, the AVL BLOW BY METER 442S can be used from small-scale and single-cylinder engines up to diesel engines for ships. 

Technical Data Unit

Measurement range

0,2 … 2,400 l/min (with different sensors)
Measurement uncertainty

<= 1,5 % FSO
<= 1,0 % FSO (with fine linearization)

Reproducibility 0,1 % of reading
Step response time < 20 ms

Maximum permissible temperature of blow-by gas

Blow by Meter Testbed

MASTER THE LEAK – blow by measurement on the next level. 

High accuracy

The accuracy of 1,0 % FSO with fine linearization (standard 1,5 % FSO) comply with the stringent legislative requirements 

Outstanding Data Quality

Exceptional data quality thanks to outstanding data rate of up to 500 Hz and state-of-the-art interfaces and interface performance. 

Reduced Setup Time

Fast testbed setup and easy integration into any automation system via CAN Bus, Analogue or Ethernet interface. 

Easy Operation and Parametrization

Thanks to the AVL Device Center software with uniform design, the measuring device can be easily operated and parameterized

Reduction of Downtimes

With the available mobile calibration unit, a professional solution for on-site calibration has been introduced. Downtimes can thus be reduced by around 85%.

Temperature Compensation

If the media temperature differs from the calibration requirements, it is recommended to use temperature compensation. Standardized adapters with temperature measurement are available for this purpose. After installation, the measuring system performs the compensation automatically. 

Pressure Compensation

For compensation of pressure deviations between media pressure and ambient pressure, the use of an absolute pressure sensor for compensation is possible. The compensation of the deviation is done automatically by the measuring system. 

Standardized Solution for Condensate Separation

With the introduction of the standardized oil separator for AVL BLOW BY METERS, a solution can be offered that reduces the effort for maintenance and increases the stability of the measurement results at the same time. 

Solution Sheet AVL BLOW BY METER

Blowby measurement on the next level


We are constantly working on new solutions. The following might be interesting for you:

AVL Fuel Reference
AVL Fuel Reference

Ensuring the efficient and professional calibration of AVL fuel consumption measurement devices according to ISO 17025.

AVL FuelExact™ Mass Flow & PLU
AVL FuelExact Mass Flow PLU

AVL FuelExactTM takes advantage of the well-established and highly precise measurement principles (PLU or Mass Flow) combined with the world’s best fuel temperature control.

Customer Services
Customer Services for Testing Solutions

The AVL Customer Services organization consists of more than 700 service- and application engineers worldwide, operating from more than 50 locations. Our global footprint is your local benefit.

75 Years Special Edition of FOCUS Magazine
75 Years Special Edition of FOCUS Magazine Now Available

With captivating stories and insightful interviews, we invite you to join us as we embark on the exciting journey of AVL, diving into our rich history and envisioning the endless possibilities ahead.

AVL 75 Years
AVL 75 Years: New Brand Movie out Now

As we have been celebrating 75 years of Reimagining Motion throughout this year, we are thrilled to release our new brand movie, commemorating this remarkable milestone of technology excellence and innovation.

EcoVision Award
AVL received the Global EcoVision Award for achievements in Hungary

AVL List GmbH received the Global EcoVision Award from WKÖ in the presence of Federal Chancellor Karl Nehammer, Federal Minister Martin Kocher, and WKÖ President Harald Mahrer for the achievements in Hungary.

AVL at the 44th Vienna Motor Symposium
AVL at the 44th Vienna Motor Symposium

What kind of cars will we be driving in the future? These and other exciting questions around the topic of "Future Mobility" were addressed by more than 1,000 participants from 25 countries at the international 44th Vienna Motor Symposium. The tenor: Future automobiles will be CO2-neutral.

AVL Brain
AVL Records Growth of 18 Percent and Continues to Invest in New and Sustainable Mobility Solutions

AVL generated 1.86 billion Euros in turnover last year – Eleven percent flows into research and development – 60 percent of the turnover is already generated by new technologies.

Reimagining Motion
AVL Mobility Accelerates Ground, Air and Space Technology

Latest projects from Northrop Grumman and Eviation presented at CES

AVL Racetech H2 Engine
AVL RACETECH Builds Hydrogen Combustion Engine for Motorsport

AVL RACETECH, the motorsport department of AVL, presents the prototype of an innovative H2 internal combustion engine. The power unit is a compact, hydrogen-powered 2-liter turbo engine, with intelligent water injection, which achieves a totally new performance level. The first racing engine that AVL RACETECH is developing and building in-house.

AVL Opens New Hydrogen and Fuel Cell Test Center in Graz

Greater test capacities for innovative energy and propulsion solutions

Everything that excels at a glance: AVL highlights you shouldn't miss.

Do you have questions or want to work with us?

Our experts are happy to help.

You are currently on the AVL Global Site. Click below if you would like to switch to