FieldScout TDR 300 Soil Moisture Meter
Manage water responsibly and reduce operating expenses.
When precision irrigation decisions count, the FieldScout TDR Series offers growers a tool to eliminate the guesswork. Based on proven time-domain measurement technology, these portable units accurately measure soil moisture across the full range of soil moisture conditions. Select from the 1.5, 3, 4.8 or 8-inch (3.8, 7.5, 12 or 20-cm) probe rods to suit your desired depth measurement. Install PVC access tubes and take readings deeper in the soil profile for permanent crops like apple, grapes, and nut crops.
The TDR 300 has two volumetric water content modes; one for standard soils and one for higher clay soils. In volumetric water content (VWC) mode, the meter converts a measured electrical signal into percent soil moisture content using an equation valid over a wide range of mineral soils. In irrigation mode, the meter displays a relative water content (RWC) on a scale of 0 to 100 corresponding to a user-defined upper and lower soil moisture reference level. Water deficit, the amount of water needed to bring the soil moisture content up to the upper reference level, is also calculated and displayed. The reference levels are easily programmed into the meter with the accompanying software. Create up to 2 management sites based on your soil types and crop needs. Use the raw reading mode (measurement period in microseconds) to do soil-specific calibrations.
Instantaneous readings of root zone soil moisture
Connects to any GPS receiver with serial output**
Equipped with internal data logger and RS-232 port
Records 3,250 measurements (1,350 with added GPS/DGPS option)
Configure and download meter with FieldScout software (included)*
Compatible with SpecMaps online web-mapping application
TDR 300 meter includes soft-sided carrying case (Item 6430CASE)
Rods sold separately
NEW CALIBRATION FEATURE ADDED IN 2012 - The TDR family of meters now includes the option to perform a calibration on an individual meter. The calibration is done in 2 media; air and distilled water. This new feature took effect with firmware version 6.5 and is included with units shipped after January 1, 2012 (purchased directly thru Spectrum). Meters with firmware versions earlier than v. 6.5 can be upgraded by purchasing and installing an updated microcontroller chip (Item #CHIP-TDR3, see above table for purchasing). See Calibration Feature of FieldScout TDR Meters for more details.
GPS Recommendation: Garmin GPS 72H Handheld GPS Navigator - Purchase through Amazon.com
The GPS 72H is a low-cost solution designed to provide precise GPS positioning using correction data obtained from the Wide Area Augmentation System (WAAS). The GPS 72H can provide position accuracy to less than three meters when receiving WAAS corrections. This rugged, waterproof, unsinkable GPS receiver offers a large, 4-level grayscale screen. It's designed as the next generation in basic, entry-level Garmin GPS. A PC serial interface cable supplied by the manufacturer of the GPS receiver is also required, this is also available on Amazon.com
* Spectrum’s PC cables connect to a 9-pin serial port. USB-Serial adapter (item 3661USB) required for connection to computers with only USB ports.
** GPS interface requires two cables. The GPS/DGPS cable (item 2950CV5) is available from Spectrum. A PC serial interface cable supplied by the manufacturer of the GPS receiver is also required.
On July 1st 2013, the 3" TDR Rod will be changing. Here is a Service Bulletin showing details of the change.
Measurement Principle: Time-domain measurement methods
Measurement Units: Percent volumetric water content
Resolution: 0.1% volumetric water content
Accuracy: ±3.0% volumetric water content with electrical conductivity < 2 mS/cm
Range: 0% to saturation (Saturation typically around 50% volumetric water)
Battery/Life: 4 AAA alkaline batteries; approximately 12-month battery life
Data Logger: 3,250 measurements without GPS; 1,350 with GPS/DGPS