非平衡电桥实验的拓展研究

Extension Study of Non-equilibrium Bridge Experiment

基于非平衡电桥工作原理,在同一测温区间内选用立式(电源对称)与卧式(输出对称)两种电桥模式,对热敏电阻升、降温过程均进行测量,比较了两种电桥在热敏电阻温度特性实验中的精度。结果表明,选用立式电桥测量热敏电阻降温过程,具有较高的精度。此外,实验中还分别提取了在不同桥臂电阻值的条件下,立式电桥的测温上限与测量精度。实验结果表明,若要保证立式电桥有足够的测温范围与较高的精度,桥臂阻值应设置1000Ω为宜。若桥臂阻值设置过大,热敏电阻的温度特性将会偏离线性关系。

Based on the working principle of non-equilibrium electric bridge,vertical(symmetrical power supply)and horizontal(symmetrical output)electric bridge modes were selected in the same temperature measurement interval to measure the temperature rise and drop of thermistor.The results show that the vertical bridge has high precision in measuring the cooling process of thermistor.In addition,the relationship between the upper limit of temperature measurement and the experimental accuracy is also studied under the condition of different bridge arm resistance values.The experimental results show that in order to ensure sufficient temperature measuring range and high accuracy of vertical bridge,the bridge arm resistance value should be set at 1000Ω.If the resistance value is set too large,the temperature characteristic of thermistor will deviate from the linear relationship.