How does a soil temperature sensor work?
Soil temperature sensor is a kind of soil temperature sensor which can monitor the temperature and humidity of soil and is used for experiment and scientific research. Soil temperature, or ground temperature for short, is a general term for surface temperature and ground temperature. Soil temperature is closely related to crop growth, fertilizer decomposition and organic matter accumulation, and is an important environmental factor in agricultural production.
Soil temperature is also an extremely important factor in the formation of microclimate, so the measurement and research of soil temperature is an important content in microclimate observation and agro-meteorological observation. The rise and fall of soil temperature is mainly determined by the magnitude and direction of soil heat flux, but also related to soil thermal properties such as soil volume heat capacity, thermal conductivity, density, specific heat and porosity, and soil water content. For non-level surfaces, it is also related to the location and size of the slope.
So how does the soil temperature sensor work?
In fact, many friends want to know the principle of this kind of sensor when they see this. In fact, it is similar to the principle of ordinary temperature sensor. It is designed by the principle of thermistor. However, compared with the conventional temperature sensor, the soil temperature sensor has The sealed housing structure with better durability ensures that the sensor can keep working when buried deep underground.
The soil moisture sensor is to monitor the humidity of the soil, and its hardware control circuit is buried in the soil moisture sensor at the root of the crop to monitor the moisture of the root soil. It is transmitted to the main controller, and the main controller determines the control state. If the humidity is too high, the irrigation will be stopped; if the humidity is too low, the solenoid valve connected to the water source will be controlled by photoelectric isolation and relay. The system also has a fault alarm function. The main controller communicates with the upper computer through the communication interface, which can monitor the system running status in real time or analyze the historical data.
The soil moisture sensor is to determine the amount of moisture in the soil to determine the moisture level of the soil. When the soil moisture sensor probe is suspended, the base of the triode is in an open circuit state, and the cut-off output of the triode is 0; when it is inserted into the soil, due to the different moisture content in the soil, the resistance value of the soil is different, and the base of the triode provides the magnitude of the change. On-current, the on-current from the collector to the emitter of the transistor is controlled by the base, and is converted into a voltage after passing through the pull-down resistor of the emitter.