What is the operating mechanism of most hydraulic pressure gauges?

The operating mechanism of most hydraulic pressure gauges is based on the design of a Bourdon tube. This device consists of a curved, hollow metal tube that tends to straighten out as pressure is applied. As hydraulic pressure increases within the system, the internal pressure forces the Bourdon tube to expand and straighten, causing the free end of the tube to move. This movement is then transmitted to a needle on a dial, indicating the pressure reading.

The Bourdon tube's design allows it to measure high pressures accurately and is widely used in various applications in the aviation industry due to its reliability and simplicity. Its effectiveness in converting mechanical movement into a readable pressure measurement makes it the preferred choice for many hydraulic pressure gauges.