## 2 Transmissibility of the Acceleration Base  
Because in the following the analysis of results is performed after vibration measurements, the way in which the standards require these measurements to be performed is briefly presented below. The methods for measuring mechanical vibrations in the hand-arm system and reporting exposure to these vibrations, transmitted by the hand along three orthogonal axes (in conformity with ISO 5349/2003), must meet some minimum requirements. This standard defines specific frequency weighting and band-pass filters to allow the uniform comparison of measurements. In most situations, measurements are made in bands of one-third of an octave, where the smallest vibrations are measured, while reporting is performed in real-time or frequency through FFT (Fast Fourier Transform) representations. This method is often the most convenient for analyzing the transmission of vibrations. Next, this paper will present studies regarding the transmissibility of the acceleration base. This is defined as the ratio of the force transmitted to the force applied. The transmitted force indicates that which is being transmitted to the foundation or the body of a particular system. The applied force is the external agent that causes the force to be generated and transmitted in the first place. Therefore, some examples of _TAB_ (_transmissibility of the acceleration base_) are derived from Figure 1, in conformity with [1], by reporting the TAB values measured at the fingers, wrist, elbow, and shoulder (for all three directions, orthogonal to the anatomical reference system), in comparison to the limits established by the SR EN ISO 5349/2003. It can be observed that only the TAB graph corresponding to the wrist follows the curve almost identically for a wide range of frequencies. In 2005, research was carried out on different types and sets of tools: for instance, [PERSON]'s research on a set of 20 vibrating tools showed the relevance of correlation coefficients (r-values), derived according to the TAB in the measured values (Table 1), in conformity with the references [1]. All these values, finally, were compared with SR EN ISO 5349/2003. In this study, all measurements were performed for six finger-hand-arm positions in conformity with [1], finding several correlations between the TAB values obtained at the head, shoulder, elbow, and wrist and accelerations given by SR EN ISO 5349/2003 [9; 10]. In conformity with [1], Figure 1a,b present the BFB factors corresponding to the weighting frequency obtained at the fingers and palm, which agree with the apparent mass values. Figure 1: (**a**) BFB factors obtained for weighted frequencies [1] and (**b**) TAB factors obtained for weighted frequencies [1]. Regarding the notion of apparent mass (dynamic force/acceleration), according to the research of [PERSON] (2006), it has been shown that the measured unweighted acceleration is more relevant in studies than the weighted acceleration and is given by the ISO standards regarding the evaluation of the conditions of occurrence of VWF (vibration white finger) syndrome. A brief explanation of the definition of weighted acceleration refers to how calculated and intense mechanical vibrations affect the human body at work or in vehicles. The resulting values are expressed as a vibration-weighted signal, a signal expressed as a function of frequency, or as their square mean. Finally, it is concluded that the vibrations of tools and devices are generally less than 250 Hz. The principle of application of the TAB and BFB measurement methods is based on the distribution of accelerations in the case of the former and the distribution of inertial forces in the case of the latter in the hand-arm system. The validation of the studies in this field was confirmed by the results obtained by [PERSON] (1999) [3] for a group of 20 vibrating tools, as well as the weighted values of the a\({}_{\text{R.MS}}\) accelerations which had been taken into account for the analysis.