A pressure-type thermometer is a fluid strength measuring device. Pressure gauges are necessary for the installation and commissioning of fluid power machinery and are indispensable when troubleshooting them. Without a pressure gauge, the fluid power system would be unpredictable and unreliable. The pressure gauge helps to ensure that there are no leaks or pressure changes that would affect the working condition of the hydraulic system.
The hydraulic system is designed to work within the set pressure range, so the pressure gauge must be rated within this range. Although the maximum hydraulic pressure is usually in the range of 3,000 to 5,000 psi, hydraulic pressure gauges can measure pressures up to 10,000 psi. The hydraulic gauge is usually installed at or near the pressure port of the pump to indicate the system pressure, but it can also be installed at any position on the machine that needs to monitor the pressure, especially if the working pressure of the sub-circuit is different from the pump pressure, such as decompression After the valve. Usually, the pressure reducing valve has an accessible gauge pressure port that allows you to directly monitor its downstream pressure setting.
Pressure gauges have been used in fluid power systems for more than a hundred years, so it may be surprising that pressure gauge designs continue to evolve. Generally, the development of pressure gauges for fluid power applications is the addition of application-specific functions. For example, the design of pressure gauges is now more conventional, with hydraulically friendly pressure ports (such as SAE/Metric straight threads) to prevent system leakage. Analog pressure gauges with custom scales are more common, and digital pressure gauges with customizable firmware allow process measurement of pressure-based leaks or other parameters such as torque, load, force, and hardness.
Ashcroft Instrument Image Pneumatic and compressed air systems are also flooded with pressure gauges because the pressure is also measured at many locations throughout the system. The pressure is measured at the receiver and each FRL or independent regulator in the system. Sometimes the pressure is also measured on pneumatic actuators. Generally, the pressure gauge factory's pneumatic pressure gauges are rated no more than 300 psi, although the pressure of a typical system is about 100 psi.
The pressure is measured in three ways-absolute pressure, gauge pressure, and vacuum. Absolute pressure is a measure of the actual pressure including ambient air, which is a zero reference under an ideal vacuum but can be as high as 14.7 psi at sea level. Absolute pressure readings are considered in applications that interact with ambient air, such as the required compression ratio calculation for flow (cfm). Gauge pressure is a zero reference value relative to ambient pressure and is used in most applications that are in ambient air but not used with ambient air, such as in fluid power systems. When disconnected from the device, the gauge pressure reads zero. Finally, vacuum "pressure" is expressed in Torr, or relative to ambient pressure, such as "in-Hg" (inches of mercury) units, which measure pressure below ambient pressure.
