VH400 - Low-Cost Soil Moisture Sensors

Soil Moisture Sensor Probe Features

• Saves water and money.
• Pays for itself.
• Rugged design for long term use.
• Waterproof and can be buried at any depth.
• Thin blade does not disturb roots.
• Probe does not corrode over time.
• Reverse Polarity Protection.
• Rapid response time.
• Accurate and precise measurement.
• Insensitive to salinity.
• Low power for battery operation.
• Measures volumetric water content (VWC).
• Measures gravimetric water content (GWC).
• Output Voltage is proportional to moisture level.
• Wide input supply voltage range.
• Connect to any decent logger or control system.

Soil Moisture Sensor Probe Applications

• Crop Steering.
• Replace sprinkler rain sensors.
• Save money - stop watering when your soil is wet.
• Compost pile monitoring and automation.
• Conduct scientific research.
• Monitor flooding.
• Get text messages and phone alerts from your plants.
• Protect concrete foundations by maintaining adequate soil moisture.
• Greenhouse Automation.

VH400 Soil Moisture Sensor Details

Water is the most precious resource on our planet. Measure it, control it, and conserve it, with our VH400 soil moisture sensor.

The VH400 is an professional electronic soil moisture sensor. It is so sensitive, that it can measure the moisture in your hands when you touch its blade.

Waterproof and Rugged

Made of durable ABS plastic, and fiberglass, our VH400 moisture sensor is absolutely water proof and rugged, ready for the most challenging application that you can throw at it. It can be buried at any depth in the ground, or be inserted above ground, or into the soil of your potted plants.

Ignores the Salt in your Soil

Most other sensors, especially conductivity or resistance based sensors are ineffective, because salts and fertilizers found in soil bias their readings. The VH400 moisture sensor uses superior transmission line techniques as does (TDR) to measure the water moisture in any soil regardless of soil salinity.

Unlike resistive or conductivity sensors, our probes do not use exposed metal to make measurements. They will never corrode, or need to be recalibrated.

Thin Blades Prevent Root Damage

Imagine your doctor giving you a shot with a syringe used for elephants. Ouch! Your plants are no different, and they will thank you for not using giant probes to take soil moisture measurements.

We designed the blade of the sensor to be as slender as possible. It can be inserted into soil and pots with minimal disturbance to the vital root systems of your plants. We have yet to find another moisture sensor with a thinner blade.

Rapid Response Time

The VH400 sensors are extremely fast. The output response is instantaneous with changes to water moisture. When you pour water on a plant, you will see the change in moisture in real time. This rapid response time allows you to walk around, and spot check the moisture of different soils and plants, by quickly sliding in the blade, and taking a measurement. We offer a handheld moisture meter with the VH400 sensor for this purpose.

Interface Our Sensors to any System

The VH400 will easily interface to any decent data logger, or microcontroller. Customers have connected it to Arduino boards, electron particle IO boards, and a slew of common microcontrollers. The output ranges from 0 to 3V so any system that can read a voltage can interface to it. For evaluation use a common volt meter to read its output, and determine the soil moisture level.

Designed to be Indestructible

Our sensor design anticipates every problem you might encounter. We've added reverse polarity protection to the 3 wire interface. If by chance you connect the three wires from the cable in the incorrect order to power, signal and ground, that's okay. The probe will not be damaged.