我是材料专业,现在正在做几种钢板的电阻点焊的两个电极间(电压\电流\电极位移\压力)的信号采集和分析.
传感器如附件所示:
1] 电流传感器:Current can be measured indirectly through measurement of voltage by either toroidal coil placed around the primary or secondary of the welding machine,then electronically integrates the voltage signal to obtain current as indicated by Faradays Law: V= A*cosθ*dI/dt, where V is measured voltage. dI/dt is change in current with respect to time. A is the area of the toroid loop. θ is the angle of the loop to the magnetic field.
2] 电压:Direct readings of voltage are obtained through voltage probes attached to either top and bottom surfaces of the materials being welded or to both spot welding electrodes.
3] 位移和压力如图所示,位移传感器有点古老(14年前的数字传感器,为了省钱暂使用中间还要转成模拟的然后送到PCI6220)。压力传感器需要经过放大器将load cell的信号转成M.U./V。
刚开始接触信号采集,有几个问题:
1. Calibrate 到底是指什么?包括哪些范畴?几个传感器通道如何calibrate?以下数据供参考
电流FSO(+-10V)积分后实际10-20KA,非常大;电压FSO(+-10V);位移FSO(0-10V);压力FSO(+-10V)
就我目前知道,位移传感器静止时采集到信号大约0.006V,满位移是9.300V,这样对应0-25mm位移量,应该可以得出y=mx+b的关系,这就是calibrate吗?
2. 传感器是否需要校准,或者在什么情况下需要校准?
多谢指教。