Explain with a neat sketch the working of Bourdon’s pressure guage.
Working: Bourdon tube pressure gauge is used to measure high pressure. It consists of tube as shown in fig. having elliptical cross section. This tube is called as Bourdons Tube. One end of this tube is connected the point whose pressure is to be measured and other end free. When fluid enters in the tube elliptical cross section of tube becomes circular. Due to this the free end of tube shifts outward. This motion is transferred through link and pointer arrangement. The pointer moves over a calibrated scale, which directly indicates the pressure in terms of N/m2 or m head of mercury. As the pressure in the case containing the bourdon tube is usually atmospheric, the pointer indicates gauge pressure.