[en] Materials testing performed on various specimen materials with different techniques often reveal measuring method problems which cannot be solved by using commercial devices which are either too expensive or else are non-existent altogether. The institute remedied this situation by developing a number of laboratory devices of their own make two of which, i.e. a special displacement transducer and a device for the calibration and characteristics determination of transducers, are demonstrated in this report. (orig./HP)

[en] A special type of pressure indicators, more or less well known under the name of 'membrane pressure indicators' is dealt with. In principle, they consist of a pipe socket which is open at one end and sealed by the 'membrane' at the other end. In case of internal pressure from the open side, the membrane will begin to arch. This arch, which is proportional to the internal pressure, is measured by suitable methods. A special form of strain ganges, so-called 'membrane pressure roses' have turned out to be particularly suitable here. The article gives general guidelines for the construction of membrane pressure indicators. (orig./HT)

[en] The tests were carried with two new cables at temperatures up to 600⁰C. The low long term shift was confirmed, but there were some outlying values which show the need for predrifting the gages before use. Satisfactory reproducibility of thermal calibration of the gages would be obtained by cutting off the welding spots. Due to the great deviation of the apparent strain it was found necessary to calibrate each single gage. In summary the tests confirmed the qualification of capacitive strain gages for creep measurements and static measurements up to 600⁰C as well. (orig./DG)

[en] This paper attempts to adapt the well-known procedure for measuring residual stresses using strain gauge technology for application to wood. (orig.)

[en] Full text: The electric properties of the films of PP and compositions on their vase are investigated. As the filler are used the piezoceramics of PCR-3M and PCR-7. The obtained experimantal results is analyzed considering the composition of polymer-segnetoelectric as the manylayer dielectric consisting of a polymer, active piezophase (ceramic) and transition layer. It is found, that at the optimal polarization temperature on the dependence of piezoelectric phase, the maximal charging of composite electret takes place at the 5% vol. for romboedric and 10% vol. for tetragonal structure. It is established that at the same conductivity of polymer phase and piezoelectric particle is obtained the optimal charging regime of electret. It is suggested, the mechanism of formation of stable electret effect in the system of polymer-segnetopiezoelectric at thermopolarization

[en] A master-slave remote handling device incorporates a set of electric resistance strain gages which monitor the forces applied by the operator to the handle to actuate an alarm if the forces are likely to damage the device. The strain gages are attached to a tubular section of the master side of the device between the handle and the first joint and comprises twelve gages arranged in groups of four. 3 figs

[en] Strain gauges are used in various applications such as wearable strain gauges and strain gauges in airplanes or structural health monitoring. Sensitivity of the strain gauge required varies, depending on the application of the strain gauge. This paper reports a tunable strain gauge based on a two-dimensional percolative network of silver nanowires. By varying the surface coverage of the nanowire network and the waviness of the nanowires in the network, the sensitivity of the strain gauge can be controlled. Hence, a tunable strain gauge can be engineered, based on demands of the application. A few applications are demonstrated. The strain gauge can be adhered to the human neck to detect throat movements and a glove integrated with such a strain gauge can detect the bending of the forefinger. Other classes of two-dimensional percolative networks of one-dimensional materials are also expected to exhibit similar tunable properties. (paper)

[en] The report describes an investigation of the only two capacitive strain gauges that are commercially available. It was found that static strain measurements are possible up to 650⁰C using CERL-Planer strain gauges. Their use at higher temperatures remains doubtful, but there is hope that improved production techniques will widen the temperature range for future lines of strain gauges. (orig./RW)

[en] Under a research contract, the Institute of Materials Testing of TUeV Rheinland, Cologne, tested capacitive strain gases with a view to applying them in creep strain mesurements. The results being promosing, TUeV Rheinland started the practical application of the technique in power stations. The velocity of creep was to be determined to estimate the strain and to control the components and to find out whether they reach the end of their service lives. By now, about 100 measurements have been taken over periods of more than 35000 hours proving the stability and the applicability of the new method. (orig.)

[en] A device is described for measuring the flow rate, in particular through large section pipes, such as those found in water type nuclear reactors, thermal power stations and gas loops. This device includes a plate drilled with holes crossed by a fluid and held in the pipe by deformable components on which are secured strain gauges forming the detecting element of an electronic device for processing the signal emitted by the gauges. This device can be employed, for instance, for measuring the flow rate of a coolant in the primary system of a nuclear reactor