The wireless pressure sensor is a low-power battery-powered (optional external power supply) wireless digital output pressure sensor. GPRS, LORa, NB-iot and other wireless communication protocols are optional. The wireless pressure sensor can display pressure in real time and upload data, and has the characteristics of high precision, convenient use and good stability. The wireless pressure sensor has a built-in MCU and a low power consumption design to realize the wireless transmission function of uploading the pipeline pressure on the spot to the cloud. It is suitable for areas that require unattended, remote monitoring, such as fire pipelines, fire terminals, fire pump rooms, smart cities, petrochemicals, and remote areas in smart fire protection.
Principle of wireless pressure sensor
Digital pressure sensor adopts the principle of piezoresistive strain. Its core component, resistance strain gauge, is a sensitive device that converts the strain change on the test piece into an electrical signal. It is one of the main components of the sensor. The most widely used resistance strain gauges are metal resistance strain gauges and semiconductor strain gauges. There are two kinds of metal resistance strain gauges: filament strain gauges and metal foil strain gauges. Usually, the strain gauges are tightly bonded to the substrate that generates mechanical strain through a special adhesive. When the stress of the substrate changes, the resistance strain gauge also deforms together, causing the resistance of the strain gauge to change, so that The voltage applied to the resistor changes. The change in resistance of such strain gauges when stressed is usually small. Generally, these strain gauges form a strain bridge, so that the change in impedance is converted into a digital signal.
Wireless pressure sensor dynamic characteristics
The so-called dynamic characteristics refer to the characteristics of the output of the sensor when its input changes. In actual work, the dynamic characteristics of the sensor are often expressed by its response to certain standard input signals. This is because the sensor's response to the standard input signal is easy to find experimentally, and there is a certain relationship between its response to the standard input signal and its response to any input signal, and the latter can often be estimated by knowing the former. Commonly used standard input signals are two kinds of step signal and sinusoidal signal, so the dynamic characteristics of the sensor are also commonly expressed by step response and frequency response.
Linearity of wireless pressure sensor
Normally, the actual static characteristic output of the sensor is a curve rather than a straight line. In actual work, in order to make the meter have a uniform scale reading, a fitting straight line is often used to approximate the actual characteristic curve, and linearity (non-linear error) is a performance index of this approximation.
There are many ways to select the fitted straight line. If the theoretical straight line connecting the zero input and the full-scale output point is used as the fitted straight line; or the theoretical straight line with the smallest sum of squared deviations from each point on the characteristic curve is used as the fitted straight line, this fitted straight line is called the least square method. Close the line.