Currently the most common type of device testing the absorbers of passenger cars in Europe are testers based on EUSAMA specification. The association of European manufacturers of absorbers EUSAMA* unified the adhesive absorber testing by creating a uniform test device with a uniform test methodology.
The advantage of adhesive resonant absorber testers is the fact that they directly assess the absorption of the unsprung vehicle mass which is the most important fact in terms of operation safety. Moreover, the result might be used without the necessity of comparing it to the data in a database.
This methodology is based on the demand for testing in conditions simulating as closely as possible the behaviour of the wheel when driving over road bumps. Adhesive resonant shock absorber testers gradually test both wheels on one axle. Measuring platform where a wheel is placed is vertically vibrated with a cam mechanism with a prescribed amplitude of 6 mm and a frequency of 25Hz. After the power to the drive is disconnected, the frequency of platform vibration decreases through the resonant frequency of the unsprung mass up to zero. During the testing process, the force spent by the wheel is sensed. This force has an efect on the strain-gauge sensors placed below the measuring platform.
*(European Shock Absorber Manufacturer Association)