Quelle est la différence entre un manomètre de pression absolue et un manomètre de pression différentielle ?

In modern industry and scientific research, pressure measurement is crucial. It is not only directly related to the safe operation of equipment, but also involves the optimization of product quality and production efficiency. To ensure measurement accuracy, scientists and engineers have designed a variety of pressure gauges, the most common of which include absolute pressure gauges and differential pressure gauges. These two instruments differ in structure and working principle, are widely used in different fields, and each has its own unique advantages and applicable scenarios. Understanding their differences and characteristics is of great significance for selecting suitable instruments, improving measurement accuracy, and ensuring operational safety.

 

Absolute pressure gauge
Absolute pressure gauges are used to measure pressure relative to vacuum, that is, their measured values ​​include atmospheric pressure. Its working principle is to compare the sensing element of the pressure gauge with the vacuum state, and measure the pressure from the surface of the object to the absolute zero point (vacuum). In short, the reading of the absolute pressure gauge is not affected by atmospheric pressure and fully reflects the absolute pressure of the gas or liquid at the measuring point.

 

The application areas of absolute pressure gauges include gas pressure measurement, vacuum equipment control, and scientific experiments that require precise absolute pressure. It is widely used in laboratories, meteorology, aerospace and other fields, especially those occasions where it is necessary to accurately know the value of pressure relative to vacuum.

 

Manomètre de pression différentielle
Le manomètre différentiel measures the difference between two pressures. Its working principle is to input two different pressures into the two sensing ends of the gauge, and by comparing the two pressures, the differential pressure gauge displays the difference between the two. Usually, the differential pressure gauge does not care about the absolute pressure value, but only cares about the relative difference between two pressure points.

 

Differential pressure gauges are widely used in air flow, liquid level monitoring, pressure difference of filters and heat exchangers, etc. For example, in air filtration systems, differential pressure gauges can be used to monitor the pressure difference on both sides of the filter to determine whether the filter needs to be cleaned or replaced.

 

Main differences
Different measurement objects:

Absolute pressure gauges measure pressure relative to vacuum.

Differential pressure gauges measure the difference between two pressure points.

Different factors affecting the reading:

The reading of an absolute pressure gauge is not affected by atmospheric pressure, it reflects the absolute pressure.

The reading of a differential pressure gauge only cares about the difference between two pressures and has no direct relationship with atmospheric pressure.

Different application areas:

Absolute pressure gauges are usually used in situations where absolute pressure values ​​are required, such as aerospace, meteorology and vacuum technology.
Differential pressure gauges are widely used in industrial control, such as filtration systems, air flow measurement and liquid level control.

 

Choosing a suitable manomètre needs to be determined according to the actual application needs. For those applications that require accurate understanding of the absolute pressure of the equipment, an absolute pressure gauge should be selected. For those applications that need to monitor pressure changes or equipment status, a differential pressure gauge is undoubtedly a more appropriate choice. Regardless of which instrument, mastering its working principle and application field, reasonable selection and correct use will significantly improve work efficiency and equipment safety.