论文部分内容阅读
一、非线性的修正方法铂热电阻的R—T关系在测量范围内是一个随温度上升,R/T比率单调下降的曲线。其表达式为 -200～O℃: R_t=R_0[1+At+Bt～2+Ct～3(t—100)] 0～650℃: R_t=R_0(1+At+Bt～2) A/D变换器的变换特性为 N=K V/V_R (1)式中,K为变换系数;V_R为基准电压;V_t为模拟输入量;N为数字输出量。如果将一定量的V_t反馈到V_R,则有
First, the non-linear correction method Platinum RTD R-T relationship within the measurement range is a rise with temperature, R / T ratio monotonically decreased curve. The expression is from -200 to 0 ° C: R_t = R_0 [1 + At + Bt~2 + Ct~3 (t-100)] 0~650 ° C .: R_t = R_0 (1 + At + Bt~2) A / D converter conversion characteristics of N = KV / V_R (1) Where, K is the conversion factor; V_R for the reference voltage; V_t for the analog input; N for the digital output. If a certain amount of V_t feedback to V_R, there