基于游标原理的A/D转换方法及其应用

A/D Conversion Method and Application Based on Vernier Principle

为了解决大量程精确测量中对分辨率要求高的问题,研究一种基于游标原理的A/D转换方法。具体方法是将待测模拟信号分为基准大量程主信号和小量程高精度的辅助信号,分别A/D转换后进行合成。利用常规分辨率的A/D转换器、单片机、运算电路可实现基于游标原理的A/D转换系统。将该方法应用于新材料的电阻温度曲线测量,应用结果显示该方法非常适合精确测取被测信号的微小变化量,即使在小信号输入情况下,仍能取得满意的测量效果。分析和实验表明:该方法可将测量器具的不确定度对测量结果的影响大大降低,可以使用常规精度的测量工具完成大量程精确测量;只要系统的灵敏度和稳定性高,被测量与基准量的差值越小,测量结果精度就越高。

In order to solve the high resolution problem for long measuring range precision measuring, the measure method based on vernier principle was studied. The method was that testing analog signal was divided fiducially main signal with long measuring range and precise assistant signal with short measuring range. They were measured respectively then assembled. A long measuring range precision measure system was made up of general resolution A/D converter, single-chip, amplifier etc. The method was used in measuring resistance with temperature curve. It is fit for precision measuring the tiny variety. The measure effect is satisfactory even if the small signal input. The analysis and application indicate that the measure device is sensitive and steady, the difference of testing signal and the fiducial signal is smaller, precision is the higher. The measure method based on vernier principle can meliorate measure device＇s incertitude performance. It can use measure tool with general precision to actualize long measuring range precision measure.