Exercises - Wheatstone bridge
Exercise 1 - Pressure sensor in a Wheatstone bridge
The sensor shown here converts the incoming pressure into a change in resistance. The diaphragm moves the wiper of the potentiometer.
Wheatstone Measuring bridge and pressure sensor
- The potentiometer has a length of 20 mm and a maximum resistance of 2 kΩ. At a pressure of 1000 mbar, the diaphragm pushes the wiper of the potentiometer 8 mm away from pin 3, at 2000 mbar it is 18 mm.
- Determine the sensitivity of the first conversion stage p → x(p)
- Determine the sensitivity of the second conversion stage x(p) → R(p) and the total conversion factor p → R(p) of the sensor.
- Sketch a suitable measuring bridge circuit to evaluate the measuring voltage and also specify the connections of the potentiometer.
- The bridge should be calibrated at a pressure of 1000 mbar. For this, dimension the resistance values.
- The supply voltage of the measuring bridge is 10 V. What measuring voltage does the measuring bridge give at a pressure of 1100 bar?