What is the difference between a pressure sensor and a pressure transmitter?

What is the difference between a pressure sensor and a pressure transmitter?

Strictly speaking, a sensor is a component of a transmitter. A  gauge pressure transmitter usually has a rod-shaped structure as its main body. The lower end of the rod is connected to the medium to be measured through a thread (or a flange, etc.), while the upper end is used to install circuit boards, connectors, displays and other electronic components.

A pressure sensor is usually encapsulated inside the rod-shaped structure of a pressure transmitter. It is the core component that senses the pressure of the medium and converts it into a relatively weak electrical signal (usually an mV signal). Such a signal has poor anti-interference ability and is difficult to be transmitted over long distances. Therefore, it needs to be converted into a standard industrial signal (such as 4-20mA, 1-5V, etc.) through a circuit board to facilitate unified control on site.

Different types of pressure sensors have different working principles and structures. For example, a common diffusion silicon sensor has a core component of a diffusion silicon core body with a size of about 1mm. The resistance inside the core body changes under the action of pressure, and thus this type of sensor is also called a piezoresistive sensor. The specific structures and characteristics of each sensor will be introduced separately in the future and will not be elaborated here.

In summary, conceptually, from large to small, they are transmitter - sensor - core body. However, in practical applications, these concepts are often used interchangeably. Many customers and manufacturers refer to the entire rod-shaped capacitance type pressure transmitter (transmitter/transducer) as a pressure sensor (sensor), and the internal sensor as a core body. Only when the product is as large as a single crystal silicon differential  smart pressure transmitter , will people basically call it a transmitter.

In the research and development and production of pressure measurement and control products, Auto Instrument fully combines the structural characteristics and functional advantages of sensors and transmitters to create multiple series of products suitable for different industrial scenarios. Its diffusion silicon pressure transmitter HART is equipped with a high-performance diffusion silicon sensor core body and is also paired with high-precision electronic components and dedicated processes, enabling the weak signal collected by the sensor to be efficiently converted into a standard industrial signal, while ensuring the stability and adaptability of the entire device. For micro-differential pressure monitoring needs, Auto Instrument has also launched a dedicated micro-differential EX pressure transmitter. The internal sensor can accurately capture small pressure changes, and the device supports on-site zero adjustment, configuration and other convenient operations, and can be combined with an upper computer to form a monitoring system to achieve remote data transmission and control. In addition, Auto's intelligent pressure transmitter adopts metal capacitor or micro-silicon solid-state composite sensor technology. Through modular design and full-range computer compensation, the overall performance of the device is further improved. It is also equipped with lightning protection circuits and multiple process interfaces, which can adapt to complex working conditions in multiple fields such as chemical, water conservancy, and thermal power. Some models also have explosion-proof and high protection level features, and can operate stably in harsh environments, fully demonstrating the important value of the collaborative work of sensors and transmitters in industrial measurement and control.

As one of the earliest enterprises in China to engage in the manufacturing of capacitive sensors, Auto Instrument has mastered the core competitiveness of measurement and control technology from the source. Its pressure and differential pressure transmitter series products are equipped with imported high-precision capacitive sensor core bodies, and the diaphragms are made of original imported materials. Combined with microprocessing technology, full-range temperature compensation is achieved, not only improving the measurement accuracy to the leading level in the industry, but also significantly improving the stability of the instrument in extreme temperature environments.

Relying on 30 years of technological accumulation, Auto Instrument has formed a multi-category core product matrix: from AT3051 and AT1151 series differential pressure transmitters, to intelligent pressure transmitters, air tightness detection sensors, and then to vortex flow meters and electromagnetic flow meters and other flow measurement and control equipment, comprehensively covering the monitoring needs of industrial core parameters such as pressure, liquid level, flow, and density. For complex working conditions in the chemical and metallurgical industries, we have specially developed customized technologies such as laser sealing processes and lightning protection circuits. Our products can handle harsh environments with high corrosion, strong vibration, and electromagnetic interference with ease. The technical adaptability covers the entire industrial scene.