## 1 Introduction
In this case, uniaxial accelerometers (with sensitivity 1 V/g and unspecified weight) were mounted to a magnetic base, and then pushed into a previously drug hole in the ground about 20 cm deep. In the research conducted by the authors of [27] a triaxial IEPE accelerometer was mounted on \"a down hole tool\", which was placed in the drilled borehole. The paper does not comprise detailed information about the accelerometer or the measurement base used in the study, nor information about the depth at which the accelerometer was placed in the borehole. A different approach to the implementation of ground vibration measurements was used in [28], in which accelerometers (most likely uniaxial with a sensitivity of 1 V/g and a weight of 210 g) were mounted to steel spikes of varying lengths driven into the ground (made of 5 mm thick steel angle bars and lengths: 500 mm, 750 mm, 1000 mm, and 1250 mm) or screwed to a metal cube with a triangular metal base placed directly on the ground surface. It was found that in the case of accelerometers attached to a metal cube at lower frequencies higher vibration acceleration values are obtained. According to the authors of the work [28], this may be related to so-called \"thermal noise\". The issue of the impact of the length of steel spikes on the level of recorded vibrations also requires further research. Various ways of coupling accelerometers to the ground were also analyzed in the paper [29]. The subject of detailed analyses were the results of vibration acceleration measurements (both in time and frequency domain) carried out using: an accelerometer mounted to an aluminum cube (with dimensions of sides equal to 100 mm) and beforehand screwed to a concrete block partially embeddedin the ground, accelerometer mounted to the aluminum cube and set on a bolt driven into the ground, as well as accelerometer bolted to a steel cross with four pins driven into the ground. In the conclusions, the authors state that \"the coupling of accelerators to the ground using crosses with four pins driven into the ground is the correct way\". A four-point ground anchored steel measuring base in the shape of cross with a screwed metal cubic for mounting accelerometers is also recommended by the Polish standard PN-B-02170: 2016-12 [25]. Measurement setup, in which high sensitivity seismic accelerometers were mounded on an aluminum cube fixed on a concrete block that was partially buried into the ground, was also utilized by authors of the work [30]. To protect accelerometers (capable of measuring ground-borne vibrations from 0.5 ug to 0.5 g in a frequency range between 0.1 Hz and 1500 Hz) from the effects of climatic conditions (such as wind and temperature), an additional protective box with Styrofoam coating at the sites was used. According to the authors of the work [30], the peak values of vibration accelerations occurring at 150 Hz and 250 Hz may result from the amplification of background noise and resonance frequency of the vibration measurement setup used in the research. The impact of different ways of coupling transducers to the ground on the recorded vibration level was also the subject of research conducted by the author of this article. The results of measurements and analyses of the recorded accelerograms were presented, among others, in [31]. Surface vibration accelerations in this case were recorded using: a cross-measuring bases set on a four bolts driven into the ground with screwed aluminum mounting cube (to which uniaxial accelerometers are mounted), a ring-measuring bases set on a three bolts driven into the ground, a two-ring-measuring bases set on a three bolts driven into the ground, and unusual measuring bases in the form of a screw recessed in the ground with miniature triaxial accelerometers mounted on the top of the screw.