EFENTO Soil Moisture & Temperature NB-IoT Data Logger

Wireless soil moisture logger is used to measure the amount of water in the soil. The sensor measures soil moisture levels and notifies of a sharp decrease or increase in the amount of water in the soil. The devices are powered by a battery that ensures their maintenance-free operation for a period of at least ten years.  The device comes in IP67 enclosure that protests it against the damage caused by water and dust.  The logger is equipped with an external Watermark soil moisture probe 3 m long and a temperature probe – 3 m.

Efento NB-IoT sensors transmit the data over cellular network (Narrowband IoT) and do not require any additional devices (router, gateway, etc.). Sensors are also equipped with Bluetooth Low Energy interface, which allows quick and easy configuration with a smartphone. Efento NB-IoT sensors can be integrated with any cloud platform.

You can use a free mobile application to configure the device and read the data from its memory.

• Measurement range: 0 - 200 Centibar (kPa)
• Temperature: -55 to +125°C, accuracy: up to 0.5°C in the range from -10°C to +85°C and up to 2°C in the range -55 to -125°C
• Measurement period: 1 minute – 10 days (configurable by the user)
• The device stores 40,000 measurements in its memory, when the memory is full, the oldest measurements are overwritten
• Battery ensures up to 5 years of maintenance-free operation
• Use a free mobile application to configure the logger, read the data from its memory, generate reports and set alert thresholds

Soil moisture sensor

How does the soil moisture sensor work? The external Watermark probe, which is placed in the soil is a resistance device that reacts to changes in soil moisture. Inside the probe there is an electrode placed in the granulate, which swells when water is taken from the soil. The granulate is enclosed in a hydrophilic material that provides good conductivity. As the soil dries, the water is removed from the sensor and the resistance measurement increases, and vice versa when the soil moisture increases, the resistance decreases. By using a coherent granulate filling the probe, the sensor has a high accuracy of the measurement. The correct reading of measurements allows accurate knowledge of soil moisture in the area of ​​the plant root system during irrigation periods and between them. The recorder has the ability to configure the measurement in the range of 1 minute to 10 days. At any time, the user can check with the Efento Logger application, the readings on the chart that create soil moisture curves, showing how the humidity level changes. Slow growth means a gradual drying of the soil, which makes it possible to maintain the desired degree of hydration and the ability to plan the frequency of irrigation. Too rapid increase of 10-15 centibars in a few days means that the soil dries very quickly and additional measures should be taken. The data obtained from the probe inform about the degree of soil hydration:

1. place the probe in the water for 30 minutes in the morning and let it dry until the evening
2. place the probe in the water for 30 minutes and let it dry overnight
3. place the probe in the water for 30 minutes in the morning and let it dry until the evening
4. place the probe in the water in the morning and leave it there until the next morning
5. the next morning, install a moist humidity probe with a temperature probe at a similar depth in the soil. To place the probe in the soil, make a hole to the desired depth. Make a thick slurry from soil and water and place at the bottom of the hole, into the resulting "mud" push the probe. Surrounding the probe with a layer of moist soil allows maximum contact of the soil with the sensor and obtaining an accurate measurement. The temperature probe is used to automatically calibrate the soil moisture probe depending on the soil temperature. It should be placed near the soil moisture probe (0.1 – 1m) – at the same depth.