FACTORS AFFECTING THE SENSITIVITY OF THE WHEATSTONE BRIDGE IN ITS PURPOSE FOR RESISTANCE MEASUREMENT

摘要

The reason for me to pick Wheatstone bridge as my subject is that it is a perfect example of electrical complexity that has many issues for many factors that have affected the flow of electricity (or have been affected from it). It is rich in topics, and I have thought that it would be a pleasure for me to do some research about it, and then present my extended essay. The part that bothered me about the measurements with the Wheatstone bridge was that, does it give precise results after it has just been balanced, or is it necessary to fulfill some conditions. For extremely precise results, the temperature must have been constant, to reduce the thermo-electric effect and keep the resistances constant. The temperature was not a problem, after it has been kept constant, but there is something more important about the resistance ratios. The current that is applied to the circuit must be suitable for the circuit, and to get the most precise results, electrical leakage that can result from the inductance or capacitance should be kept as minimum. The resistance to be measured and the one to be adjusted would be the only variable resistances, and the other ones should be kept in a constant ratio. In this experiment, they were kept to a constant ratio of 1 in order to have a wide range of measurement.