This part of ISO 10846 specifies a method for determining the dynamic transfer stiffness for translations of resilient supports, under specified preload. The method concerns the laboratory measurement of vibrations on the input side and blocking output forces and is called “the direct method”. The method is applicable to test elements with parallel flanges (see Figure 1). Resilient elements, which are the subject of this part of ISO 10846, are those which are used to reduce the transmission of vibration in the lower part of the audible frequency range (typically 20 Hz to 500 Hz) to a structure which may, for example, radiate unwanted fluid-borne sound (airborne, waterborne or others), and the transmission of low-frequency vibrations (typically 1 Hz to 80 Hz), which may, for example, act upon human subjects or cause damage to structures of any size when vibration is too severe. NOTE 1 In practice, the size of the available test rig(s) can restrict the use of very small or very large resilient supports. NOTE 2 Samples of continuous supports of strips and mats are included in this method. Whether or not the sample describes the behaviour of the complex system sufficiently is the responsibility of the user of this part of ISO 10846. Measurements for translations normal and transverse to the flanges are covered in this part of ISO 10846. The direct method covers the frequency range from 1 Hz up to a frequency fUL, which is usually determined by the test rig. NOTE 3 Because of the large variety of test rigs and test elements, fUL is variable. In this part of ISO 10846, the adequacy of the test rig is not defined for a fixed frequency range, but on the basis of measured data, as described in 6.1 to 6.4.