m|ars – Fast and reliable measurement of flow resistance
The m|ars measuring system by Müller-BBM enables measurement of flow resistance in accordance with the DIN EN 29053 standard, hence a convenient assessment of the sound-absorption capacity of various materials. The short measurement duration of only a few minutes' and the small sizes of samples, make flow resistance measurement using m|ars an excellent solution for routine production monitoring. Even when it comes to selecting suitable materials or developing new materials, a pre-selection can be made quickly and simply with the help of m|ars.
The measuring principle
m|ars uses the direct airflow method, as described in Standard EN 29053 for measurement of flow resistance. To do this, a constant volume flow is passed through the sample. The overpressure that builds up in front of the sample is measured. The ratio of overpressure to flow velocity produces the flow resistance, which with most porous materials is independent of flow velocity.
According to EN 29053, the flow resistance extrapolated at a flow velocity of 0.5 mm/s is referred to as specific flow resistance.
The measuring device
m|ars is equipped with high-grade measurement transducers in order to provide precise results even at low flow velocities. These make it possible to measure the volume flow and differential pressure with the highest resolution. Sensors for temperature, humidity, and atmospheric pressure automatically and continually detect ambient conditions.
m|ars is equipped with a pressure cylinder for measurement. Different sample holders for the various types of samples are then attached to it. Thin samples, such as fabrics or felts are clamped to a flange. Thick, flexible samples can be pressed to a given thickness. A set of tubes of varying lengths makes it possible to measure solid samples.
The software provided with the device controls the automatic measurement procedure, and displays the results clearly.
Technical specifications
- Volume flow is controllable between 0.1 Nl/min and 6 Nl/min
- Differential pressure can be measured between 0.1 Pa and 10 Pa
- Measurable flow resistance between 10 Pa s/m and 40,000 Pa s/m
System requirements
- Dry compressed air that is oil and particle free (1 bar – 15 bar)
- PC with Windows XP or higher and a USB port
The order includes
- Sample container with various attachments for measurement of thin, pressed or thick samples
- Measuring unit with pressure reducer, volume-flow controller, differential-pressure measuring system and air-pressure sensor
- Measuring sensor for measurement of temperature and humidity in the sample container
- Tubes for connecting sample containers with measuring unit
- Strike template for preparing flat samples
- 2 reference flow resistors
- USB cable for connecting measuring unit to the computer
- Software and manual in PDF format