扩散硅压阻式压力传感器的压力测量实验

实验十一扩散硅压阻式压力传感器的压力测量实验一、实验目的：了解扩散硅压阻式压力传感器测量压力的原理与方法。二、实验仪器压力传感器模块、温度传感器模块、数显单元、直流稳压源+5V、±15V。三、实验原理在具有压阻效应的半导体材料上用扩散或离子注入法，摩托罗拉公司设计出X形硅压力传感器如下图所示：在单晶硅膜片表面形成4个阻值相等的电阻条。并将它们连接成惠斯通电桥，电桥电源端和输出端引出，用制造集成电路的方法封装起来，制成扩散硅压阻式压力传感器。扩散硅压力传感器的工作原理：在X形硅压力传感器的一个方向上加偏置电压形成电流展当敏感芯片没有外加压力作用，内部电桥处于平衡状态，当有剪切力作用时，在垂直电流方向将会产生电场变化E=Ap-i，该电场的变化引起电位变化，则在端可得到被与电流垂直方向的两测压力引起的输出电压Uo。U=d-E=d-Ap-i（11-1）O式中d为元件两端距离。Uo图1T电流实验接线图如图11-2所示，MPX10有4个引出脚，1脚接地、2脚为Uo+、3脚接+5V电源、4脚为Uo-；当P1>P2时，输出为正；Uo图1T电流四、实验内容与步骤1.接入+5丫、±15丫直流稳压择20V档，打开实验台总电源。.调节Rw2到适当位置并保与节Rw3使直流电压表200mV档显力一.气室1、2的两个活塞退回到刻度"1/"的小孔后，便两，1、气至的压刀和河天气压咫为0，气压计指在“零”刻度处，将MPX10的输出接到差动放大器的输入端Ui，调节Rw1使直流电压表200mv档显示为零。.保持负压力输入P2压力零不变，增大正压力输入P1的压力到0.01MPa，每隔0.005Mpa记下模块输出Uo2的电压值。直到P1的压力达到0.095Mpa；填入下表1。.保持正压力输入P1压力0.095Mpa不变，增大负压力输入P2的压力，从0.01MPa每隔0.005Mpa记下模块输出Uo2的电压值。直到P2的压力达到0.095Mpa；填入下表2。.保持负压力输入P2压力0.095Mpa不变，减小正压力输入P1的压力，每隔0.005Mpa

记下模块输出Uo2的电压值。直到P1的压力为0.005Mpa；填入下表3。.保持负压力输入P1压力0Mpa不变，减小正压力输入P2的压力，每隔0.005Mpa记下模块输出Uo2的电压值。直到P2的压力为0.005Mpa；填入下表。10．实验结束后，关闭实验台电源，整理好实验设备。五、实验数据记录与分析1、保持负压力输入P2压力零不变，增大正压力输入P1的压力P1(kP)0.010.0150.0200.0250.0300.0350.0400.0450.050Uo2(V)1.6082.283.023.544.224.895.456.076.63P1(kP)0.0550.0600.0650.0700.0750.0800.0850.0900.095Uo2(V)7.057.798.218.739.259.6210.0310.5811.04（表1）用matlab绘制P1-Uo2曲线图如下图所示P1-UC曲线图2、保持正压力输入P1压力0.095Mpa不变，增大负压力输入P2的压力P2(kP)0.010.0150.0200.0250.0300.0350.0400.0450.050Uo2(V)10.149.769.328.828.367.857.416.796.23P2(kP)0.0550.0600.0650.0700.0750.0800.0850.0900.095Uo2(V)5.725.084.593.853.262.561.681.120.32（表2）用matlab绘制P2-Uo2曲线图如下图所示减减/JP2-U02线003、保持负压力输入P2压力0.095Mpa不变，减小正压力输入P1的压力P1(kP)0.0900.0850.0800.0750.0700.0650.0600.0550.050Uo2(V)-0.67-1.33-1.95-2.57-3.13-3.67-3.95-4.51-5.13P1(kP)0.0450.0400.0350.0300.0250.0200.0150.0100.005Uo2(V)-5.57-6.01-6.27-6.70-7.18-7.52-7.90-8.22-8.55（表3）用matlab绘制P1-Uo2曲线图如下图所示0.0050.010.0150.020.0250.030.0350.040.0450.050.0550.060.0650.070.0750.080.0850.09P2/kPO7-V/2oU00.0050.010.0150.020.0250.030.0350.040.0450.050.0550.060.0650.070.0750.080.0850.09P1/kP减0.0050.010.0150.020.0250.030.0350.040.0450.050.0550.060.0650.070.0750.080.0850.09P2/kPO7-V/2oU00.0050.010.0150.020.0250.030.0350.040.0450.050.0550.060.0650.070.0750.080.0850.09P1/kP减/JP1-U曲线图0-4-5V/2oU-8-9

4、保持负压力输入P1压力0Mpa不变，减小正压力输入P2的压力P2(kP)0.0900.0850.0800.0750.0700.0650.0600.0550.050Uo2(V)-8.05-7.71-7.30-6.92-6.50-6.11-5.70-5.34-4.89P2(kP)0.0450.0400.0350.0300.0250.0200.0150.0100.005Uo2(V)-4.39-3.92-3.42-2.86-2.30-1.65-1.07-0.400.29（表4）用matlab绘制的P2-Uo2曲线图如下图所示减小P2-UC曲线V/2oU0.0050.010.0150.02V/2oU0.0050.010.0150.020.0250.030.0350.040.0450.050.0550.060.0650.070.0750.080.0850.09P2/kPO5、灵敏度及非线性误差计算线性拟合直线的斜率即为所求的灵敏度，故对上面的曲线图依次进行线性拟合，如下图所示（红色为拟合直线），并由此算出其灵敏度和非线性误差。灵敏度L=AU/AP拟合直线斜率非线性误差6f=△m/yFSX100%（△m为输出值与拟合直线的最大偏差，yF.S为满量程输出平均值）（1）P1-UC拟合直线0.0050.010.0150.020.0250.030.0350.040.0450.050.0550.060.0650.070.0750.080.0850.090.0950.1P1/kP2（1）P1-UC拟合直线0.0050.010.0150.020.0250.030.0350.040.0450.050.0550.060.0650.070.0750.080.0850.090.0950.1P1/kP2O8642V/2oUy=p1*x+p2pl=110.3p2=0.87657由图读出^m=0.392故灵敏度S=L=AU/AP非线性误差6f=(0.392/11.4)X100%=3.5%P2-Uo2曲线图0.0050.010.0150.020.0250.030.0350.040.0450.050.055P2-Uo2曲线图0.0050.010.0150.020.0250.030.0350.040.0450.050.0550.060.0650.070.0750.080.0850.090.095气压P2/kPp2=11.765由图读出Am=0.650.1208642V/2oUy=p1*x+p2p1=-115.24故灵敏度L=AU/AP-1v1/k5p.24非线性误差6f=(0.65/10.72)X100%=6.1%减小「1山。2曲线图0.005减小「1山。2曲线图0.0050.010.0150.020.0250.030.0350.040.0450.050.0550.060.0650.070.0750.080.0850.09P1/kPy=p1*x+p2p1=91.498p2=-9.3923由图读出Am=0.450-7V/2oU故灵敏度L=AU/AP非线性误差6f=(0.45/8.87)X100%=5.1%减小P2-Uo曲线0.0050.010.0150.020.0250.030.0350.040.0450.050.0550.060.0650.070.0750.080.0850.09P2/kPy=p1*x+p2pl=-96