Compressed air is supplied from the main through pipeline 1 and partly enters tube 2, immersed in water and used as a pressure stabilizer, and partly passes through restrictor a into measuring chamber 3. From the measuring chamber, air is admitted through nozzle 4. The work being checked is placed under contact tip 7. Depending upon the clearance between the nozzle and the flat head of the contact tip, a definite pressure is established in measuring chamber 3. This pressure is measured by watercolumn pressure gauge (manometer) 6. This pressure indicates whether the work is within the required limits of size.
$3702$SHP,M$