Soil sensors have been developed to precisely monitor soil moisture levels. With their help, you can easily determine the exact amount of water your crops need. This can help you make smart buying decisions and improve crop production. You can also use the information gathered to maintain your lawn and garden efficiently.
Soil moisture sensors are available in two forms – resistive and ultrasonic. The resistive type is usually more reliable and ideal for small-scale operations. They have a built-in circuit that emits ultrasound waves. These signals are too small to be heard by the human ear. However, they are detectable by objects that are electrically charged.
The most common assistive soil sensor moisture sensor is the thermoelectric type. They can be installed inside or outside. The device has a sensing component and uses an electric current to generate heat that heats up the soil. When the temperature rises, the internal circuit senses the change in temperature and converts it to sound. In the absence of moisture, the sensor will not function. The internal circuit will shut off automatically when the temperature falls below a pre-determined threshold.
Capacitive soil moisture sensor devices, on the other hand, work differently. Their principle is based on the fact that water contains different amounts of molecules. Some water molecules have high electrical charges and others have low charges. The presence of moisture increases the number of negatively charged water molecules. As a result, the amount of electrical charge of each molecule is higher than its average number. Like resistive sensors, this type of sensor can detect changes in temperature.
Two other types of soil moisture sensors are the ultrasonic and the capacitive. Capacitive sensors work by creating ultrasound sounds. They usually generate microwaves, which are strong enough to penetrate the upper layer of soil.
Both ultrasonic and capacitive soil moisture sensors generate ultrasound sounds that are heard by nearby receivers. Based on the principle that water molecules have different electrical charges, such sensors can differentiate between water content and the presence of existing microbes. This means that these two types of sensors can detect the presence of mold or fungi in the soil.
The resistive soil moisture sensor works by detecting changes in the soil’s water content. It does so by passing an electric current through the sample. The frequency of passing the current determines the depth of penetration. For this reason, resistive sensors are commonly used in conjunction with ultrasound technology.
Capacitive moisture sensors operate at a lower frequency than resistive soil moisture sensors. As the name of the class suggests, its function is to determine the amount of water content in the soil. This type of sensor has two different types of receivers: one uses surface acoustic wave technology and the other employs an electrical field to excite the moisture in the soil. For this reason, this type of soil moisture sensor can detect the moisture level in shallow areas and at a greater distance. Unlike resistive sensors, it does not use ultrasound technology to detect moisture changes.
Both of the soil moisture sensors mentioned above utilize transducers which send their signals via electrodes to a base shield. The main difference between the two is that the former implements electrical impulses, while the latter uses ultrasound waves. Thus, soil moisture sensors that employ the former utilize electric impulses. On the other hand, those that employ the latter utilize ultrasound waves.
You may have noticed that the resistive and the capacitive soil moisture sensors are quite similar in many ways. There are also some differences that you will have to consider when purchasing your own sensors. Resistive soil moisture sensors are generally less expensive than the capacitive ones. Moreover, they are easier to install since there are no wires to connect them. Some even come with a compact carrying case so that you do not need to get a power source.
When selecting a soil moisture sensor, make sure that it is able to sense moisture changes in soil at a relatively large distance. If it can only detect changes within a few millimeters of its range, then you might as well find another one. You should be able to determine if its signal can penetrate the ground sufficiently and that it has the necessary sensitivity to establish a reliable soil moisture level reading.
There are a couple of other features to look for when shopping for soil moisture sensors. One of the most important is the soil depth penetration ability of the sensor. Make sure that the sensor can detect changes in soil moisture level very accurately, especially when it is set up in areas with different soil types. Also, you should check the sensitivity of the soil moisture sensor. Some soil moisture sensors offer extremely sensitive signals, which can be easily contaminated by nearby moisture sources. Thus, it is very important that you know and understand the requirements of your system before going out to purchase one.