Soil water potential sensor

1.Soil water potential sensor product introduction

Soil water potential sensor is a tensiometer type of soil water potential sensor, which has the characteristics of ultra-fast response time, high precision and compatibility.Plants need a certain amount of soil water to grow, and the content of soil water has an important impact on plant growth and development. With the development of agriculture, the requirements for crop yield and quality are getting higher and higher, so it is necessary to know the precise irrigation cycle of plants and give them an irrigation time point. Soil water potential sensor can provide such an irrigation point. It can clearly tell growers whether the plants are short of water, how long they will be short of water, and how often they should be irrigated, thereby improving the product quality of crops.

In modern agriculture, the role of soil water potential sensor is very significant. After collecting the dynamic content data of soil moisture of the planted crops, more precise irrigation measures can be taken according to the growth changes of the crops. It can not only record the soil tension change data, but also help growers to continuously supplement the soil environment data of the crop types, which is of great significance to improving crop varieties, quality and yield.

The soil water potential sensor uses a transparent PVC plastic tube, which can clearly show the amount of water remaining in the device, making it easy to add water. It also uses a -100-0Kpa vacuum gauge, which allows users to clearly view data. The product is suitable for places where soil moisture and drought information need to be detected, and is mostly used in agricultural crop planting to monitor whether crops are short of water, so as to better irrigate crops.

When the PVC pipe of the equipment is filled with water, the pressure inside the PVC pipe is 0 compared with the atmospheric pressure. After the equipment is inserted into the soil, part of the water inside the PVC pipe will be absorbed by the soil, causing negative pressure inside the pipe. The greater the absolute value of the negative pressure in a standard unit time, the stronger the soil's water absorption capacity and the more water-deficient the soil.

2. Soil water potential sensor product features

1. Protection grade: IP67

2. Overall structure: The product adopts a bottom monitoring structure. The bottom of the equipment is inserted into the soil to the depth that needs to be monitored. The specific insertion depth can be customized according to site requirements.

3. Equipment size: The insertion depth is 60cm, which can be increased by multiples of 15CM, up to a maximum of 120cm.

4. Maximum power consumption: 0.8W (24V DC power supply)

5. Equipment material: Transparent PVC plastic tube, you can clearly see the amount of water remaining in the equipment, which is convenient for adding water.

6.Communication interface: RS485.

7. Power supply mode: 5-30vdc wide voltage power supply.

8.Working environment: 0℃~+60℃.

9.Default accuracy: ±0.5kpa (25℃).

10. Range: -100kpa~0kpa

11. Resolution: 0.1kpa

3. How to install the soil water potential sensor

1. Installation location

The equipment should be installed after the crops are sown; the equipment installation site should be selected at a relatively high and flat place to prevent rainwater from flowing back into the equipment and causing equipment short circuit or line failure.

Under full irrigation conditions, areas with less water should be selected as monitoring locations; under partial irrigation conditions, wet areas should be selected as monitoring locations;

Select a location where the crop growth is balanced and representative of the growth of most crops;

Understand the root distribution of the monitored crops and generally choose a location close to the crop's water-absorbing roots to determine the height of the equipment.

2. Installation method

The installation method is drilling and grouting. Please refer to the instructions for details.

3. Installation method

Prepare cold boiled water: Boil the tap water for 20 minutes and set aside to cool.

Venting the clay head: inject cold boiled water, fill it up, and stand the instrument upright for 10-40 minutes (do not add the lid). When water drips from the surface of the clay head, plug it with the silicone plug and wrap the clay head with a paper towel to absorb water. Make the soil tension reach about -40kpa. When bubbles rise, shake the equipment to vent as much as possible. Repeat this process 2-3 times.

Submerge the clay head in water, wait until the soil tension returns to within -10kpa, fill it up with water again, plug it with the silicone plug, screw on the top end cap, and set it aside.

4. Notes

The clay head must not be contaminated with oil to avoid clogging the micropores and causing the instrument to malfunction.

The instrument range is -100Kpa-0. When this limit is exceeded, the instrument will leak due to the rupture of the clay head tube wall, making the instrument ineffective.

Check regularly and add cold boiled water to the sensor about once every half a month to a month (or wait until the water level drops to the top of the gas collecting pipe to add water). Do not loosen the sensor during the filling process.

Before the temperature drops to 0℃, outdoor instruments should be removed to avoid freezing and cracking.

-10~0kpa indicates humidity, which is too high for most crops.

-30~-10kpa means moist, suitable for the growth of most crops.

-50~-30kpa means dryness, and moisture-loving crops need to be watered.

＜-50kpa, indicating dryness, most crops need irrigation.