Our VH400 series soil moisture sensor probes
enable precise low cost monitoring of soil water content.
Because our probe measures the dielectric constant of the soil using
transmission line techniques, it is insensitive to water salinity, and
will not corrode over time as does conductivity based probes. Our
probes are small, rugged, and low power.
Compared to other low cost sensor such as gypsum block sensors, our
probes offer a rapid response time. They can be inserted and
take an accurate reading in under a second.
Probes come in standard cable lengths of 2 meters,
5 meters and 10 meters.
Soil Moisture Sensor Probe Applications
Irrigation and sprinkler systems.
Moisture monitoring of bulk foods.
Rain and weather monitoring.
Water conservation applications.
VH400 - Soil Moisture Sensor Probe
Soil Moisture Sensor Probe Features
Extreme low cost with volume pricing.
Not conductivity based.
Insensitive to salinity.
Probe does not corrode over time.
Rugged design for long term use.
Consumes less than 7mA for very low power operation.
Measures volumetric water content (VWC) or gravimetric water content (GWC).
Output Voltage is proportional to moisture level.
Wide supply voltage range.
Can be buried and is water proof.
Probe is long and slender for wider use, including smaller potted plants.
The quickest way to evaluate if the VH400 series is
right for you is to also order some of our sensor relay
boards. The relay
boards accept input from a single sensor and control a solid
state or mechanical relay. The relay contacts can be
configured to close when wet, or open when wet. The dry/wet
threshold is easily set by an an on boardvariable resistor,
which can be tuned with a small screwdriver. With our relay
boards, within minutes you'll be using your VH400 soil moisture probe
to control, valves, alarms or home automation
How to Get Started with the Soil Moisture Sensor Probe
The best way to get started is to purchase a few low
cost soil moisture sensor probes and try them out in your
Bury the sensor at root level. Since the sensor takes an average across the blade, for a precise reading at a particular
depth, bury it horizontally such that water will not pool up on the blade.
Many PLC's have a 24V output, which is too high for the VH400 sensor.
A resistor voltage divider can be used to drop the voltage in half. To do this, use
two 600 ohm 1/4W resistors in series, tied from the 24V to ground. The center of the
resistors can be tapped to supply 12V. Note that this is not a very power