Tensiometer Transducers

GT3 Jet fill Tensiometer Transducers

The vacuum inside the tensiometer is measured by a pressure transducer, which gives a continuous analogue output signal. A resolution of 0.1 kPa (1 cm H2O) can be attained for the GT3 Tensiometer Transducer.
Available models:

• GT3-15 0 to -100 kPa Jet fill Tensiometer Transducers
• GT3-30 -100 to 200 kPa Jet fill Tensiometer Transducers
• GT3-1 Custom Tensiometer Transducers

GT3-420 Jet fill Tensiometer Transducers

The GT3-420 has an industry-standard 4 to 20mA current loop output that can be used to interface it to a wide variety of standard devices including programmable logic controllers (PLCs) and data loggers.

Tensiometer & Pressure Transducer Interfaces

The interface is necessary to connect the tensiometers to the smart logger.

Available models:

• ST1 – Interface for GT3 Standard Tensiometer
• ST1–A – Interface (mV Output) for Vacuum Transducers with either 1 PSI, 15 PSI or 30 PSI range
• ST1–A – ST1-A Interface (mV Output) for Honeywell Transducers with either 1 PSI, 15 PSI or 30 PSI range
• ST1–B1 – Interface (kPa Output) for 1 PSI Transducers
• ST1–B2 – ST1-B2 Interface (kPa Output) for 15 PSI Transducers
• ST1–B3 – ST1-B3 Interface (kPa Output) for 30 PSI Transducers

 

Request Quote | Specification Sheet

 

GT3-15 0 to -100 kPa Jet fill Tensiometer Transducers

Transducer connection

Red	+10 V power supply
Yellow	Signal output "+"
	Pressure change from 0 to -100 kPa
	Output from 0 to -100 mV
Black	Battery ground
Blue	Signal output "-"

Ordering Information

GT3-15	Transducer with 1/4 inch NPT thread, 1 m cable
ST1	Optional interface for use with ICT Smart Logger

Note: Customers requiring cable lengths greater than 1 m are requested to source cable locally. Standard 4 wire cable is required.

 

Request Quote | Specification Sheet

 

GT3-30 -100 to 200 kPa Jet fill Tensiometer Transducers

Transducer connection

Red	+10 V power supply
Yellow	Signal output "+"
	Pressure change from -100 to 200 kPa
	Output from -50 to 100 mV
Black	Battery ground
Blue	Signal output "-"

Ordering Information

GT3-30	Transducer with 1/4 inch NPT thread, 1 m cable
ST1	Optional interface for use with ICT Smart Logger

Note: Customers requiring cable lengths greater than 1 m are requested to source cable locally. Standard 4 wire cable is required.

 

Request Quote | Specification Sheet

 

GT3-1 Custom Tensiometer Transducers

Transducer connection

Red	+10 V power supply
Yellow	Signal output "+"
	Pressure change from 0 to -7 kPa
	Output from 0 to -20 mV
Black	Battery ground
Blue	Signal output "-"

Ordering Information

GT3-1	Transducer with 1/4 inch NPT thread, 1 m cable
ST1	Optional interface for use with ICT Smart Logger

Note: Customers requiring cable lengths greater than 1 m are requested to source cable locally. Standard 4 wire cable is required.

 

Request Quote | Specification Sheet

 

GT3-420 Jet fill Tensiometer Transducers

The GT3-420 has an industry-standard 4 to 20mA current loop output that can be used to interface it to a wide variety of standard devices including programmable logic controllers (PLCs) and data loggers.

Measuring Principle

The soil water tension is transmitted via the ceramic cup into the tensiometer. The vacuum inside the tensiometer is measured by a pressure transducer, which gives a continuous analogue output signal.

Resolution and Accuracy

A resolution of 0.1 kPa (1 cm H₂O) can be attained for the GT3 Tensiometer Transducer. The accuracy actually obtained is related to the calibration and resolution of the analogue to digital converter. In field applications the values obtained should consider the shaft/cup length of the tensiometer: 1 cm = 0.1 kPa.

Ordering Information

GT3-420

Transducer with 1/4 inch NPT thread, 1 m cable

Notes:

• Customers requiring cable lengths greater than 1 m are requested to source cable locally.
• Voltage range is dependant on load resistance; For example, For a load of between 130-200 ohm the minimum voltage would be 16 V.

 

Request Quote | Specification Sheet

 

Tensiometer & Pressure Transducer Interfaces

ST1	Interface for GT3 Standard Tensiometer
	Range of Response:	0 to 100 kPa
	Output Display:	0 to 100 kPa
	Output Calibration:	Calibration for a 15 PSI Transducer at 4.2V
ST1-A	Interface (mV Output) for Vacuum Transducers with either 1 PSI, 15 PSI or 30 PSI range
	Range of Response:	-100 kPa to 200 kPa
	Output Display:	- or + mV in the range -50 mV to 100 mV Convention is negative for vacuum and no sign for positive pressure.
	Output Calibration:	The customer can connect a Vacuum Transducer of choice 1 PSI, 15 PSI or 30 PSI. The output in mV will not exceed the output display range of -50 mV to 100 mV at 4.2 V regulated power supply. The interface output in mV is linear and therefore a 2 point calibration (slope) only is required to convert mV to cm of water or kPa for either the 1 PSI, 15 PSI or 30 PSI Vacuum Transducers.
ST1-B	Interface (kPa Output) for Vacuum Transducers with either 1 PSI, 15 PSI or 30 PSI range
	Range of Response:	-100 kPa to 200 kPa
	Output Display:	kPa in the range -100 to 200 kPa Convention is negative for a vacuum and no sign for a positive pressure.
	Output Calibration:	Calibration for the respective 1 PSI, 15 PSI or 30 PSI at 4.2 V

Note: Customers must specify which pressure transducer type is to be connected to the ST1-B. A transducer specific calibration is required as the response of each of the 1 PSI, 15 PSI or 30 PSI Vacuum Transducers is different in sensitivity of PSI to mV. This correct calibration curve must be known to accurately convert the raw output to kPa.

 

More Information

• GT3 Jet fill Tensiometer Transducers
• Interfaces Notes

 

Links and Brochures

Printer-friendly version of GT3-15 Brochure (PDF)

Printer-friendly version of GT3-30 Brochure (PDF)

Printer-friendly version of GT3-1 Brochure (PDF)

Printer-friendly version of GT3-420 Brochure (PDF)

Printer-friendly version of Custom Tensiometer Transducers Interfaces (PDF)

Transducer References

Jet Fill Tensiometers

Soil Science Instrumentation

FieldStation

Irrigation Solutions