The study of weight measuring devices based on ring of elastic sensitive element and secondary sensor string

Inductive, capacitive and strain gauge transducers of strain are used as the most common sensors of the amount of deformation of the elastic element measuring devices. In known sensors of converting nonelectrical quantities into electric signal is performed in two stages: the first stage is the conversion to change one of the parameters (inductance, capacitance, resistance, etc.), then this change is converted into an electrical value. The main problems of such sensors is their high dependence on the stability of their parameters, temperature dependence and relatively low sensitivity due to the measurement only of the magnitude of deformation. The disadvantages of analogue should include the principle of operation, while the main electric transducers are fixed frequency changes. To address this shortcoming in the design of the device is inserted into the input blocks, sending the analog signal in frequency. These devices have a very weak output signal and to output it to the required level applied to the amplifiers. The presence of the circuit signal conversion of a large number of additional links significantly reduces the measurement accuracy. For force measuring devices, it is advisable to use a string sensor (SD). This sensor has high accuracy and low inertia. Error DM hysteresis does not exceed 5 g to 15 kg applied weight. The article presents the results of a study of the static and dynamic charac- teristics of the original structures, measuring devices based on the annular elastic element of variable cross section and built-in string gauge. The studies have confirmed the efficiency of the devices in a wide range of loads shows high sensi- tivity and measurement accuracy. However, a significant drawback of SD is the increased sensitivity to external distur- bances. SD converts the external force in the vibration of the string, and its high accuracy will be provided only in the event if don’t have any external sources of vibrations that can lead to significant errors of measurement.