Abstract. One of the major errors directly influencing the metrological characteristics of the integrating measuring strain gauge converter is the inequality of the output voltages of the comparator. The current paper explores the effect of the voltages variation at the output of the comparator in the case of a bipolar power supply of the converter. The output data is obtained by modeling the equation of conversion in the MATLAB environment. The fore-mentioned problem is investigated assuming up to 20% inequality of the output voltages compared to the supply voltage and a bilateral change of the load on the strain gauges. A regression analysis is performed checking the suitability of a linear, quadratic and cubic model. It shows that the coefficient of determination is highest for the cubic model and relevant conclusions are made.Keywords: comparator, converter, modeling, regression analysis, strain gauges 1
Introduction.Strain gauges measuring converters are intended to amplify and convert the small output voltages that are obtained in disbalance of strain gauges bridge, which is known as "Wheatstone bridge". Every "Wheatstone bridge" consists of two or four strain gauges that are connected in half bridge or full bridge. The output voltage is proportional to the deformation of the strain gauges sensors. Depending on the mode of guidance (method of orientation) for bonding, the strain gauges can measure forces, moments, weight, etc.The transformation of the change of the strain gauges deformation into frequency deviation is done by integrating converters working on the method of ramp right conversion. The method itself is well known and reported by many scientists: (Шахов, 1986) , (Mochizuki,1996), (Kaliyugavaradan, 2000), (Madhu, 2009(Madhu, ), (Гигов, 2013, (Станков, 2014) and many others. Essential advantages of the method are simplicity circuits and high linearity conversion. The main disadvantages are the requirements for using high performance elements, fast operational amplifiers, and accurate selection of measurement ranges. Therefore, there is no coincidence that most schemes of integrating converters have patent protection rights, namely (Mильченко,