Acclima TDT hygrometer + EC/temperature sensor

The Acclima Digital TDT soil moisture sensor represents a revolutionary advance in the irrigation industry.
It is the first soil moisture sensor to incorporate the accuracy of digitized Time Domain Transmissometry in a low-cost instrument providing highly accurate absolute readings of soil moisture under all conditions of temperature and soil chemistry where crops will grow.
No other TDT sensor on the market matches its accuracy and stability.
Independent test data from leading soil physicists verifies this extraordinary claim and are available upon request.
This Digital TDT sensor incorporates a modified SDI interface capable of connecting directly to Acclima data loggers or any other third-party SDI version 1.4 compliant device.

Main features:

Works in all soils
Highly stable under a wide range of soil conductivity and temperature
Range of 0-100% volumetric water content
Made with durable inert materials
Very low-power, battery operable
SDI-12 version 1.4 compliant
Low cost

Physical characteristics:

Dimensions (without cable): 20cm x 5,33cm x 1,5cm
Weight (with 10m cable): 480g
Composition: type 304 stainless steel, crystalline-epoxy
PVC (insulation) cable: 3 conductor, 22ga PVC sheath, 10m long

Environmental characteristics:

Operating temperature range: 1°C to 50°C for VWC (no ice), -20°C to 50°C for the other data
Storage temperature range: 20°C to 75°C
Lightning & surge protection: 6kV-3kA, 8/50µs

Operating characteristics:

Volumetric water content: 0 to 100%
Resolution: 0.06% VWC
Absolute VWC accuracy: ±2% typical
VWC soil EC stability: ±1% of full scale 0 to 5dS/m BEC
Temperature reporting accuracy: ±2°C in the range of +1°C to +50°C
EC reporting accuracy: ±0.2dS/m 0 to 5dS/m BEC

Architectural characteristics:

Technology: waveform digitizing time domain transmissometer
Effective acquisition bandwidth: 200 Giga-sample/s
Propagation time resolution: ps
Waveguide length: 30cm
Permittivity to VWC calculation: modified dielectric mixing
Propagation waveform bandwidth: > 2GHz

Communications characteristics:

Communication protocol: SDI-12 Revision 1.4
Maximum cable length: 60m

Power characteristics:

Operating voltage range: 6–15 VDC
Listening/sleep mode current: 60µA at 50°C
Communications current: 6mA typical, 8mA max
Read moisture communication time: 425ms total for each read cycle
Moisture sense current: 84mA at 12VDC input, 98mA at 8 VDC input, 110mA at 6 VDC input
Moisture sense time: 450ms each sensing operation