Soil Moisture Sensor Probe Comparison

Here's a comparison of various soil moisture sensor probes from various venders. If a field is left blank then information on the product is unknown. We invite all soil manufacturers to contact us and add their soil moisture sensor probe products to this comparison.

Click here to see Vegetronix's offerings of low cost, high accuracy soil moisture sensor probes.

What should I look for when choosing a Soil Moisture Sensor Probe?

  • Price - Let's face it, this is usually the most critical parameter when selecting anything. The VH400 series of soil moisture sensor probes leads the pack in pricing. If you are the first person to find a comparable probe for a lower price let us know, and we'll send you a gift certificate to the Olive Garden!
  • Power - For battery applications power efficiency is critical. We have yet to find a lower power soil moisture sensor probe in the same class as the VH400 series.
  • Technology - Many "cheap" soil moisture sensor probes use what is called resistive or conductive sensing of the soil. The problem with these sorts of probes is that they corrode and rust over time, since bare metal of the soil moisture sensor probe is exposed to the soil. If this weren't bad enough, they also give inaccurate results since soils with different salinity levels give different readings. These sorts of low tech soil moisture sensor probes should be avoided because of their short life span and inaccurate results. The VH400 series use superior sensing technology and will never corrode, and is insensitive to salinity.
  • Form Factor - The VH400 probes are long and slender and so they can be used in more applications than their bulky competitors, including monitoring of smaller potted plants.
  • Durability - Avoid any soil moisture sensor probes that measure conductivity or resistance, since they will wear out over time.
  • Accuracy and Linearity - A quality soil moisture sensor probe should give an output which is proportional to water content over the full output range. In addition, the soil moisture sensor probe should have a good output range to reduce sensitivity to noise.
  • Supply Voltage Range - Many inferior soil moisture sensor probes must be powered with a specific voltage, otherwise the will be damaged or give inconsistent results. The VH400 series soil moisture sensor probes have voltage ranges that span 2V to over 20VDC. In addition, their outputs are consistent over the full supply voltage range.

Recommended Soil Moisture Sensor Probes:

Manufacturer Sensor Technology Current (mA) Input Voltage Price 1 Unit
Vegetronix VH400 Dielectric 12 3.3 to 24V $39.95

Other Miscellaneous Soil Moisture Sensor Probes:

Acclima Digital TDT Dielectric 80,000 6 to 12V
Aquaflex SI.99 Dielectric ~ $1020.00
AquaPro AP Moisture Probe Dielectric 18,000 5.5 to 17V ~ $1000.00
aquaSpi Soil Moisture Probe Capacitive 1640 7.5 to 16V
AquaTerr M-300 Dielectric 9V
AquaTerr T-300 Dielectric 9V
AquaTerr EC-300 Dielectric 9V
Campbell Scientific CS615-L Dielectric 70,000 12V
Dynamax ThetaProbe Dielectric 15,000 5 to 15V
Dynamax TH20 Dielectric 19,000 5 to 15V
Environmental Sensors Moisture Point Dielectric
Environmental Sensors Gro-Point Dielectric
Decagon Devices EC-5, 5TE, 10HS, EC-TM, EC-20, EA-10, MPS-1 Dielectric
Netafin Dielectric
LusterLeaf Rapitest Meter 1820 Resistive
SDEC HMS9000 Dielectric 20,000 8 to 24V
SDEC STM 2150 Tensiometer
SenTek Diviner2000 Dielectric
Soilmoisture Equipment G-Block Resistive
Soilmoisture Equipment Trase Dielectric
Spectrum Technologies TDR 100, 6440FSS Dielectric $250.00
Spectrum Technologies TDR 200, 6435FS Dielectric $745.00
Spectrum Technologies TDR 300, 6430FS Dielectric $895.00
Stevens Water Hydra Probe Dielectric 40,000 7 to 30V
Troxler Sentry 200-CP Dielectric
WaterMark 6450 Resistive $34.00
Vernier SMS-BTA Dielectric $91.00

Soil Moisture Sensor Probe Manufacturers
Comparison Table
(Information as of 2009)