Talking about quartz weighing sensor

What is quartz?

Quartz is a mineral widely found in nature. Like common sand, crystal and other materials, its main component is silicon dioxide, chemical formula SiO2. But due to the different arrangement of molecules, it has different appearances and characteristics.

Pure quartz is colorless and transparent, and its thermal, chemical and mechanical properties have obvious anisotropy. The melting point is 1750℃. Quartz has strong piezoelectric property, that is, sparks will be generated when it is struck and rubbed hard, which is the method of making fire with flint.

Development of quartz piezoelectric effect

In 1880, brothers Jacques and Pierre Curie accidentally discovered the magical piezoelectric effect of quartz crystal. They found that when quartz crystal is subjected to heavy pressure, electric charge will be generated on its surface, and the amount of charge generated is proportional to the mass of the substance.

However, the collection and retention of charge requires very high impedance conditions, otherwise it is easy to discharge and even more difficult to measure it. It was not until the 1950s that the charge amplifier (CA, Charge Amplifier) was invented to convert the charge into a corresponding voltage signal, realizing the measurement and processing of charge by conventional instruments and devices for the first time, thus creating the field of piezoelectric measurement.

In the 1960s, the Swiss Federal Institute of Technology in Zurich developed a piezoelectric quartz force sensor.

In the 1970s, piezoelectric quartz three-component force measurement systems were used in engineering, automotive industry and biomechanics.

Application of quartz weighing sensor

In the 1990s, Switzerland developed a dynamic weighing sensor with quartz crystal as sensitive element that can be used on roads. Due to its small size, low height, light weight, high rigidity, high natural frequency, wide dynamic range and high sensitivity. Therefore, it has achieved good application results in the fields of vehicle overload axle load prediction, bridge overload alarm, tunnel protection and vehicle axle load measurement.

It is widely used in many countries such as the United States, the United Kingdom, Germany, Australia, South Korea, and Japan. Since the end of the last century, with the development of the domestic freight situation and the need for national governance of overload and overloading, my country has also developed quartz weighing sensors suitable for road applications in my country.

Weighing principle of quartz weighing sensor

Quartz weighing sensor is a device that uses the piezoelectric effect of quartz crystal to convert weight signal into electrical signal.

1). The quartz crystal detection element converts the dynamic tire force into a charge signal;

2). It is converted into analog voltage through the charge amplifier;

3). The analog signal is then converted into a digital signal through the A/D converter;

4). Finally, the weighing result is obtained through the embedded computer and its dedicated software.

The structure of quartz load cell

Appearance of quartz load cell

Advantages of quartz weighing sensors

1) Wide effective dynamic detection speed range: high rigidity, no deformation under heavy load, high frequency response, and can accurately measure rapidly changing dynamic loads.

2) Strong durability: Withstood 5400000 times of 50KN load durability test without any signs of damage.

3) Long service life: Service life exceeds 100 million axles.

4) Accurate dynamic weighing performance: Good linearity, repeatability and stability.

5) Wide temperature adaptability range: Temperature changes have no effect on weighing accuracy, and no recalibration is required.

6) Easy installation and fast construction: small construction volume, less road damage, and short cycle.

7) Strong concealment: After installation, it forms a whole with the road surface, and it is difficult for the driver to accurately judge its specific location.

8) Maintenance-free: No drainage is required, eliminating daily maintenance in the application.