A certain type of pressure transducer, designed to measure pressures in the range 0-10 bar, consists of a diaphragm with a strain gauge cemented to it to detect diaphragm deflections. The strain gauge has a nominal resistance of 120 2 and forms one arm of a Wheatstone bridge circuit, with the other three arms each having a resistance of 120 12. Bridge output is measured by an instrument whose input impedance can be assumed infinite. If, in order to limit heating effects, the maximum permissible gauge i current is 30 mA calculate the maximum permissible bridge excitation voltage.! If the sensitivity of the strain gauge is 338 m2/bar and the maximum bridge excitation voltage is used, calculate the bridge output voltage when measuring the pressure of 10 bar

 

120 120 12.4 Figre Dectionype de brid