The Design Of Electronic Scales Based On Resistor Strain Type Weight Sensor

Electronic scales have the merit of high precision and quick speed of measuring, it can read the result conveniently and can get rid of the tare automatically, having a series of advantages, making electronic scales widely used in industrial production,process controlling, teaching and research and our daily life. Besides being used to do normal measuring,the electronic scales can still be used in some special situations to measure the quantity of the materials, such as doing precision metage in chemistry experiment,weighing up and counting the number of the horologe component in horologe factory, weighing up the radioactive materials etc. The electronic scale designed in this paper will be applied in food humidity measuring instruments, to weigh up the sample during the drying process.The special applied situation needs this electionic scale to satisfy another condition besides being used to do normal weight mesearing,which is keeping high accuaracy when the exterior environment temperature varies greatly, According to the request mentioned above, this paper chooses resistor strain type weight sensor, adopts the proportion voltage measuring method, uses 24-bit A/D Convertor, designed an electronic scale of high accuracy.This paper first analys the working principle of resistor strain slice, its measuring method, temperature characteristic and corresponding compensation methods, then in the hardware designing,this paper adopts proportion voltage measuring method, connects the reference voltage of the high precision A/D convertor and the voltage of strain bridge of the weight sensor together, to remove the affection of the voltage of strain bridge of weight sensor to the measuring result, also to remove the affection of the reference voltage of A/D convertor to output result. Because the A/D convertor adopted is 24-bit, it integrates the analog power supply, digital power supply, analog ground and digital ground inside, and...