The BZ5681 digital three channel stress-strain sensor has the following significant advantages.

1. No cable connection required:Use wireless digital communication to exchange data.

2. No need to replace battery:The sensor is powered by an external energy harvesting power source. The sensor does not need to be replaced within its service life.

3. No need for massive data transmission:Sensors calculate and process large amounts of collected data, outputting concise results without the need to directly upload massive amounts of data.

4. No need to consume port energy:All sensors come with their own energy harvesting power supply, which is environmentally friendly and does not require energy from ports. Beneficial for the construction of green ports.

Outstanding features in principle design.

The problems that need to be solved in surface measurement of steel structures include measurement accuracy, time stability, and temperature stability. It is to accurately separate the stress deformation and temperature deformation generated on the surface of the steel structure over a long period of time. At present, the main principle design methods in China include: pasting strain gauges, installing fiber Bragg grating sensors, installing vibrating wire sensors, and installing strain sensors. These methods have their own advantages and disadvantages, and have not yet reached the advanced level of all three indicators.

The BZ5681 digital three channel stress-strain sensor has the following outstanding features.

1. Accuracy.

Strain measurement technology is currently recognized as a high-precision measurement technology in the field of strain measurement in the industry. For example, a weighing sensor can easily achieve an accuracy of 0.02% at a very low cost. Therefore, the method of sticking strain gauges is widely used in short-term strain measurement of large structures.

2. Long term stability

High temperature curing process for attaching strain gauges, with a stability of at least ten years. This is also a good characteristic exhibited by weighing sensors.

3. The temperature adaptive strain conversion technology separates the influence of temperature.

This is a patented technology. In principle, the influence of temperature can be completely offset, and the influence of temperature can be controlled within the error range in batch products.

4. Resolve high integration anti-interference issues.

Small analog signals of strain conversion, high-frequency digital signals of microcontrollers, and higher frequency radio transmission signals are collected in a narrow space. It can ensure that the small analog signals converted by strain are not disturbed by digital signals that are millions of times higher than themselves at close range.

5. Design sensors with ultra-low energy consumption.

To design ultra-low energy sensors in strain measurement technology, the first step is to address the energy consumption of the bridge supply. Three channels require three times the energy, and in conventional designs, at least 100 milliwatts of energy are needed to stabilize the sensor signal. This sensor provides a maximum bridge energy of 0.9 milliwatts, which can be as small as 0.1 milliwatts, making it quite technically challenging.

6. Resolve the energy supply issue of sensors.

Install an energy harvesting power supply to power the sensor. Energy harvesting power sources collect light energy, vibration energy, and electromagnetic energy in batteries. At present, in the design of this project, light energy is collected and converted into electrical energy. The solar weak panel has an area of 60mm x 60mm and does not need to face the sun. It can meet the electricity consumption of this project in any direction during the day. When light energy is converted into electrical energy, the intensity of light changes over time, and the converted electrical energy also changes over time. An energy harvesting chip is used to decompose the changing electrical energy into stable charging voltage and changing current to charge the battery.

Main technical indicators.

1. Strain measurement range: ± 5000 μ ε.

2. Strain resolution: 0.1 μ ε.

3. Principal stress resolution: 0.01MPa.

4. Stress angle resolution: 0.01 °.

5. Measurement accuracy: 0.1%.

6. A/D conversion accuracy: 24 bits.

7. Sampling rates: 1.25Hz, 12.5Hz, 50Hz can be set. Factory setting: 12.5Hz.

8. Data processing time interval: 10-90 seconds. Factory setting: 10 seconds

9. Wireless communication data transmission rate: 115200b/s.

10. Wireless communication frequency band: 433MHz.

11. Wireless transmission power: 6.25, 12.5, 25, 50, 100mW can be set. Factory setting: 25mW.

12. Wireless reception sensitivity: -100dB.

13. Wireless communication time interval: adjustable from 15 to 45 minutes. Factory setting: 20 minutes.

14. Working temperature range: -40~+80 ℃.

15. Sealing grade: IP67.

16. Dimensions: 90mm * 90mm * 60.5mm.

17. Weight: 200g.

18. Installation method: adhesive.

19. Digital input elastic modulus: three bytes, unit: MPa/ε.

20. Digital input Poisson's ratio: two bytes, Poisson's ratio * 65536.

21. Other contents of digital communication: refer to the "Communication Protocol".

22. Temperature output function: Digital output -40~+80 ℃, suitable for further temperature compensation of data.