A bellows sensor is a sensor that measures the gravity or pressure of an object by detecting the deformation of a metal bellows. The bellows sensor is usually composed of bellows, Bridges, amplifying and filtering circuits. When an external force compresses or stretches the bellows, the bending degree of the metal bellows will change, resulting in a change in the output voltage of the power bridge. By measuring this voltage change, the gravity or pressure of the object under test can be deduced. The working principle of the bellows sensor is as follows: When the object under test is subjected to gravity or pressure, the bellows will undergo a small deformation, compression or extension of the bellows. After deformation, the stress and strain state inside the bellows change, making the inner diameter and thickness of the bellows change slightly.
To detect this small change, bellows sensors usually use a bridge circuit to measure the degree of strain inside the bellows. The sensor's built-in bridge consists of four resistors distributed on a complete tolerance ring, which is connected to an electronic circuit through a signal line inside the sensor during operation. When the bellows are deformed, the bridge made up of these resistors produces a tiny voltage output signal
Finally, a standard electrical signal proportional to the gravity or pressure of the measured object, that is, the electrical signal output by the sensor, can be obtained by processing and converting the tiny voltage signal output by the amplifier and filter circuit, so as to achieve the measurement of the gravity or pressure of the measured object. The following is a typical parameter of the bellows sensor: Range :0-5kg to 0-10000kg Accuracy grade: generally 0.1 or 0.2. Output signal: 0-5V, 0-10V, 4-20mA, etc. Nominal sensitivity: 2mV/V, 2.5mV/V, 3mVV Working voltage :10VDC~30VDC. Force mode: Pressure is added to the dead point of the sensor or full scale long-term stability: typical value is 0.1%~0.2% per year Linear error: usually in the range of 0.05%~0.2% per range.
Influence of ambient temperature: The typical value is that the output offset caused by temperature change is 0.01%~0.02% for every 10C. It should be noted that the parameter table of the bellows sensor may vary depending on factors such as manufacturer, model and application environment. When using a bellows sensor, select the appropriate sensor model and parameters based on the specific application environment and requirements, and follow the installation and maintenance guide provided by the manufacturer to ensure the stability and reliability of the sensor
