| 摘要 |
<p>A measurement system of the type having a sensor the electrical resistance of which varies as a function of a parameter being measured, and a bridge circuit connected to the sensor, wherein a source of a reference voltage is provided to excite the bridge to produce a bridge output indicative of the parameter being measured when the bridge is balance, the bridge output being dependent upon the sensor resistance and the reference voltage except that the system includes circuitry for causing the output to be independent of the reference voltage at one end of a range of values of the parameter, and output circuitry is provided for converting the bridge output into a system output in accordance with an output function, featuring, in one aspect, first calibration circuitry connected to the output circuitry to provide a first calibration signal for calibrating the system at one end of the range by controlling the output function; second calibration circuitry connected to the bridge circuit to provide a second calibration signal for calibrating the system at the other end of the range by controlling the effective value of the reference voltage supplied to the bridge circuit: sequencing circuitry for automatically causing the first calibration circuitry to calibrate the system at one end of the range, and then automatically causing the second calibration circuitry to calibrate the system at the other end of the range; and a control for activating said sequencing circuitry.</p> |
