Product news

In today's age of high environmental awareness, precise noise measurement is of crucial importance.

For this purpose, Microtech Gefell GmbH/MTG traditionally manufactures a series of precision measuring microphones with weather protection for temporary and permanent installations, especially for the automotive industry. The microphones are approved for official calibration/PTP certification and can be used for legally binding measurements. This means that the microphones are compatible with all common monitoring measurement systems and some are equipped with a remote calibration system.

In response to the growing demand for digitalization in the field of noise monitoring (e.g. traffic noise), MTG recently presented the newly developed WME 980 CN measurement microphone with horizontal sound incidence in relation to the microphone axis, equipped with a digital measurement amplifier.

A further development step in this context is pass-by solutions with synchronization via GPS signal.

In addition to the precision microphones mentioned above, a remarkable number of individual, turnkey solutions in the field of special test benches (airborne/structural sound, modal analysis, hydropulse, etc.*) have been successfully realized in recent times. (* excluding construction, interior fittings and drive technology)

MTG's range of services also includes the planning of engineering projects, consulting as well as the development and turnkey realization of special test benches and equipment, in particular for the field of vehicle interior/exterior noise and vibration measurements.

Exterior noise measurements are of growing importance for vehicle development as well as in production quality assurance and are decisive for type approval.
In order to obtain type approval for motor vehicles as a prerequisite for distribution on various markets, it is necessary to carry out a type test, e.g. in accordance with the DIN ISO 362-1:2017-10 standard, in order to meet the acoustic requirements.

For this purpose, a special driving cycle is completed on a defined test track. A special acoustic measurement system, various control signals such as light barriers, speed measurement system, GPS if necessary, climate data acquisition and road temperature measurement are integrated into the system. These are realized through installation planning and implementation for fixed installations of pass-by test stands under field conditions.

Weatherproof microphones are used for fixed installations, e.g. type WME 980 CN. Together with the sound level measurement system used, these form a sound level measurement chain that is used to check the standard values and at the same time to analyze the driving noise in terms of frequency

In order to develop motor vehicles in advance of type testing to meet the different global standards for driving noise, test benches are used for simulated pass-by driving with a stationary vehicle on a chassis dynamometer and microphones arranged in lateral rows. The rows of microphones are used to simulate a pass-by of the vehicle by the software. MTG also has extensive experience in the planning and installation of such test benches and is able to integrate the components required in addition to the measurement system.
The structural and building services, such as acoustic room equipment and drive systems, are coordinated by MTG for the projects, but are not part of Microtech Gefell's scope of work.

High-quality sound - also a decisive factor in the development of electromobility

MTG also offers tools and equipment for sound engineers who develop the sound of electric cars. Pass-by noise measurement in accordance with DIN ISO 362-1:2017-10 as a standard procedure for all approved vehicles is also suitable for electric vehicle noise. On the one hand, there are real pass-by test benches in weatherproof outdoor facilities with two obligatory measuring microphones and, on the other hand, simulation pass-by test benches with up to 64 microphone channels in very large indoor facilities with acoustic elements. There are room acoustic systems that allow a measurement limit that covers a range from 40Hz to 20kHz and more. Although this requirement for the lower cut-off frequency originates from combustion engines, it can also be applied to creations in the world of electric mobility sound reinforcement.