Absolute pressure sensors and gauge pressure sensors are common types of pressure sensors. They have different working principles and application scenarios when measuring pressure. The difference between absolute pressure sensors and gauge pressure sensors will be introduced in detail below.
First of all, absolute pressure sensors measure pressure relative to vacuum, while gauge pressure sensors measure pressure relative to atmospheric pressure. The reference point of the absolute pressure sensor is vacuum, which can measure negative pressure values below atmospheric pressure, such as measuring pressure changes in a vacuum container or closed system. The reference point of the gauge pressure sensor is atmospheric pressure. It can only measure the positive pressure value relative to atmospheric pressure and is used to measure pressure changes in general environments.
Simply put, the absolute pressure sensor measures absolute pressure inside. Gauge pressure sensors measure pressure relative to atmospheric pressure. The first is the difference in their accuracy. The gauge pressure sensor measures the pressure relative to the ambient atmospheric pressure, so the accuracy is relatively high. Absolute pressure measures absolute pressure, and there is no direct comparison, so the accuracy will be poor and it will be greatly affected by the environment. The second is that the gauge pressure sensor must have an air guide hole connected to the atmospheric pressure, so the production process of the gauge pressure sensor will be more complicated, especially when working in water, an air guide tube is required.
Secondly, the absolute pressure sensor needs to be connected to a known vacuum environment during the measurement process to provide a reference pressure. Typically, the back of an absolute pressure sensor is sealed and isolated from the external environment. The gauge pressure sensor does not need to be connected to a vacuum environment, but is directly connected to the atmosphere, and can directly measure the pressure change relative to atmospheric pressure.
For example, the absolute pressure sensor IM2623M700-N10A is a sealed, small-volume and high-performance sensor with a range of 0~700KPA. It is mainly used in electronic products in the field of precision measurement, such as air pumps, air pressure gauges and other products.
In addition, the output value of an absolute pressure sensor is usually positive, indicating pressure relative to vacuum. When an absolute pressure sensor measures atmospheric pressure, the output value is zero. The output value of a gauge pressure sensor is usually based on atmospheric pressure. When atmospheric pressure is measured, the output value is zero. When a pressure higher than atmospheric pressure is measured, the output value is positive.
Finally, due to different working principles and measurement ranges, the application scenarios of absolute pressure sensors and gauge pressure sensors are also different. Absolute pressure sensors are usually suitable for scenarios where negative pressure values need to be measured, such as vacuum equipment, sealed containers, etc. Gauge pressure sensors are suitable for scenarios where positive pressure values relative to atmospheric pressure need to be measured, such as environmental monitoring, fluid control, etc.
To sum up, there are obvious differences between absolute pressure sensors and gauge pressure sensors in terms of measurement principles, reference points, output values and application scenarios. Understanding these differences can help us select the type of pressure sensor suitable for specific needs and ensure the accuracy and reliability of measurement results.