Gauge pressure transmitter: The measurement reference point of a gauge pressure transmitter is "local atmospheric pressure". One side of its sensor diaphragm senses the process pressure, while the other side is directly exposed to the atmosphere. Therefore, its reading directly reflects the extent to which the process pressure is higher or lower than the atmospheric pressure.

1. Directly Reflects "Useful" Pressure: In the vast majority of industrial processes (such as pipeline pressure, tank pressure, and pump outlet pressure), what we are concerned about is the pressure relative to the external environment. Gauge pressure directly provides this information without the need for secondary calculation.
2. Relatively Simple Structure: As the reference end is open to the atmosphere, there is no need to create a sealed vacuum reference chamber as in absolute pressure transmitters, resulting in typically lower manufacturing costs.
3. Easy Installation and Zero Point Calibration: Before installation or upon power-on, as long as the atmospheric vent is unobstructed, the output will naturally be at the zero point (corresponding to local atmospheric pressure). Minor drifts in the zero point can also be easily corrected on-site through "atmospheric zeroing".
4. High Versatility: It covers the vast majority of industrial pressure measurement scenarios from micro-pressure to high pressure.

Gauge pressure transmitters are used to measure pressure in non-hermetic systems or relative to atmospheric pressure.

1. Pipeline pressure monitoring: Pressure in water, oil, gas, steam, etc. pipelines.
2. Pumps and compressors: Monitoring outlet/inlet pressure to prevent pump blockage or cavitation.
3. Storage tanks and containers: Liquid level measurement in atmospheric or slightly pressurized tanks (based on hydrostatic principle), and monitoring of breather valve pressure.
4. HVAC systems: Monitoring static pressure in air ducts and differential pressure across filters.
5. Hydraulic and pneumatic systems: Control of power source pressure.
6. Process reactors: Control of reaction pressure.
7. Boilers: Control of steam pressure.

Gauge pressure transmitters are the "main force" and "default choice" in industrial pressure measurement. They are designed intuitively, in line with the common human understanding of pressure ("How many kilograms does the pressure gauge show?" refers to gauge pressure), and can meet the pressure measurement needs of over 80% of industrial sites.