Graeff provides remote monitoring solutions for wind turbine foundation structure automation monitoring, urban comprehensive pipe gallery settlement automation monitoring, municipal engineering intelligent transportation, urban central heating center pipeline pressure, temperature, flow, etc

The basic requirement of a smart city is that objects in the city are connected, and sensors corresponding to each object that needs to be identified and managed must be installed. At present, sensors, as an important component of the Internet of Things, have been raised to new heights. The research and development of new sensors continues to heat up, and their market position is increasingly prominent; Whether in industrial manufacturing, home life, environmental protection, biomedicine, urban transportation, or logistics transportation, many sub fields of the Internet of Things cannot do without sensors with different functions.

Therefore, the upgrading and replacement of sensors have become the key to the rapid development of smart cities

Let's learn about the latest developments and applications in the field of smart city construction closely related to Graeff sensor technology?

1. Multiple sensors assist in the maintenance of green spaces in Nanjing city

At present, Nanjing is accelerating the application of smart gardens in the maintenance of urban landscaping projects. The Nanjing greening and landscaping department has set up 200 monitoring points in green spaces such as main roads and squares. Two soil moisture monitoring points have been set up by the garden maintenance unit on the green space of Moonlight Square in Gulou District. The small pole is equipped with solar panels to power the entire monitoring and control system. A small cover plate is installed underground in front of the pole, which houses soil moisture sensors, temperature sensors, rainfall sensors, as well as solenoid valves and flow sensors for the water supply pipe.

Insert the Graeff sensor into the green underground to monitor soil moisture, temperature, and other indicators in real time. When the humidity drops below a certain value, the irrigation system will automatically start watering. This irrigation intelligent control and monitoring system not only monitors soil moisture, but also monitors temperature and rainfall in the environment. For example, if the humidity is below 50%, the solenoid valve will automatically open for watering; When the temperature is below 5 ℃, regardless of the humidity, the solenoid valve will automatically close to prevent freezing caused by watering. For better monitoring of soil moisture and temperature, it is recommended to use the Italian Nessa Soil Moisture (Humidity) Sensor - SUT, which is a device that detects soil dielectric constant through high-frequency measurement (70MHz). The magnitude of this value depends on the soil moisture and is not sensitive to water mineralization. Water in soil is a conductor, and its concentration can be used to obtain an indication of the relative humidity of the soil. The sensor automatically performs temperature compensation and outputs standard 4-20 mA, 0-2Vdc or digital RS485/Modbus using MCS module. The sensor can be easily connected to any acquisition system, which allows for the calculation of VWC values through approximate equations.

The Graeff flow sensor monitors the flow rate of the water supply pipe and warns of possible pipeline damage. For flow monitoring, Gongcaiwang recommends using the Swissflow low-pressure flowmeter - SF800 from the Netherlands. SF800 is a cost-effective universal flowmeter with a working temperature range of -20~+90 ° C, a working pressure of 16 bar (maximum 40 bar), and a flow rate range of 0.5~20 liters per minute. It has a wide range of uses and is suitable for various applications and fluids. On the other hand, the entire SF800 machine is made of high-quality plastics and composite materials with excellent chemical and thermal recovery properties. The shell material is made of PVDF (a high-grade PVC), while the internal rotor weighs only 0.04 grams and is made of an extremely lightweight liquid crystal polymer Vectra. Both materials are not easily affected by scale. The integrated PCB emits an infrared signal, which is interrupted by the three blades of the rotor. SMD components convert interrupted signals into pulses. The structure and geometry of the rotor housing of the SwissFlow flow sensor enable it to withstand high pressure.

2. Install 345 Graeff air quality sensors in Hsinchu, Taiwan

Recently, Hsinchu, Taiwan installed 345 miniature air quality sensors to monitor air quality. Graeff miniature sensors are attached to lamp posts at a height of about 3 meters from the ground. The monitoring items include temperature, humidity, fine particulate matter (PM2.5), wind speed, wind direction, and other data, which can be generated in just 3 minutes. Among them, the Hsinchu Science Park, Xiangshan Industrial Zone, and transportation arteries have the most constructions, allowing the public to check air quality online, take appropriate measures, and protect their health. In addition, 8 wind speed and direction sensors will be added this year to enhance the effectiveness of environmental analysis.

Graeff miniature sensors can monitor changes in air quality 24 hours a day. Once an abnormality occurs, the system will issue a warning, and inspectors can use computer data to real-time grasp possible illegal sources and events of air pollution emissions, making inspection efficiency twice the result with half the effort. The TGS2600, a Japanese figaro air quality sensor/VOC sensor provided by Gongcaiwang, is an imported air quality sensor from Japan with high sensitivity to extremely weak air pollutants (focusing on cigarette smoke). Like the hydrogen or carbon monoxide present in cigarette smoke, this air quality sensor can detect several ppm of hydrogen. Due to its miniaturization, the TGS2600 only requires a heater current of 42mA and adopts a standard TO-5 metal package for its casing. In addition, the sensitive element of the sensor is composed of an integrated heater and a metal oxide semiconductor on an alumina substrate. If there is an object detection gas in the air, the higher the concentration of the gas, the higher the conductivity of the sensor. With a simple circuit, the change in conductivity can be converted into a signal output corresponding to the gas concentration.

3. Installing a health monitoring system for cross line overpasses on highways in Zhengzhou

Bridge safety has always been an important component of the safe operation of highways and a top priority in daily bridge maintenance work. Currently, in the 16 years since the opening of the Zhengzhou Shaoguan Expressway in Henan Province, bridge diseases have become increasingly diverse, complex, and concealed. Recently, in order to ensure the safe operation of the overpass along the Zhengshao Expressway, a set of overpass health monitoring system will be installed on the bridge. It is reported that the project will begin implementation on October 9th and is expected to be completed by late October. It is reported that the monitoring system used in this project is mainly based on building attitude sensors developed in cooperation with foreign companies, plus sensors such as crack needles and resistance strain gauges, to achieve the purpose of automated monitoring of pedestrian bridges. On the other hand, the project installs sensors at the main load-bearing parts of the bridge to achieve the four real-time and effective regulatory goals of "real-time monitoring, real-time communication, real-time calculation, and real-time warning".