Mt10 Soil Moisture Sensor Temperature Sensor Replace 5TM by Decagon

1 Introduction
Thank you for choosing MT-10 Soil Moisture and Temperature sensor. This manual can help you understand the sensor features and ensure successful sensor operation. We hope you find the contents of this manual useful in understanding your instrument and maximizing its         benefit to you.
There are several ways to contact MT-10 if you ever need assistance with your product, have any questions, or feedback. MT-10 has Customer Service Representatives available to speak with you Monday through Friday, between 7am and 5pm Pacific time. Note: If you purchased your sensor through a distributor, please contact them for assistance.
If contacting us by email or fax, please include as part of your message your instrument serial number, your name, address, phone, fax number, and a description of your problem or question. Please read these instructions before operating your sensor to ensure that it performs to its full potential.
 
1.1 Warranty
The sensor has a 30-day satisfaction guarantee and a one-year warranty on parts and labor. Your warranty automatically validates upon receipt of the instrument.
 
1.2 Seller's Liability
Seller warrants new equipment of its own manufacture against defective workmanship and materials for a period of one year from the date of receipt of equipment.
Note: We do not consider the results of ordinary wear and tear, neglect, misuse, accident as defects. The Seller's liability for defective parts shall in no event exceed the furnishing of replacement parts \freight on board" the factory where originally manufactured. Material and equipment covered hereby which is not manufactured by Seller shall be covered only by the warranty of its manufacturer. Seller shall not be liable to Buyer for loss, damage or injuries to persons (including death), or to property or things of whatsoever kind (including, but not without limitation, loss of anticipated profits), occasioned by or arising out of the installation, operation, use, misuse, nonuse, repair, or replacement of said material and equipment, or out of the use of any method or process for which the same may be employed. The use of this equipment constitutes Buyer's acceptance of the terms set forth in this warranty. There are no understandings, representations, or warranties of any kind, express, implied, statutory or otherwise (including, but without limitation, the implied warranties of merchantability and fitness for a particular purpose), not expressly set forth herein.
2 About MT-10
We designed the MT-10 to measure the water content, electrical conductivity, and temperature of soil. The MT-10 uses an oscillator running at 70 MHz to measure the dielectric permittivity of soil to determine the water content. A thermistor in thermal contact with the sensor prongs provides the soil temperature. The Polyurethane coating on the MT-10 circuit board protects the components from water damage and gives the sensor a longer life span.
2.1 Specifications
Volumetric Water Content
Range: Apparent dielectric permittivity ("a): 1 (air) to 80 (water)
 
Resolution: "a: 0.1 "a (unitless) from 1 to 20, < 0.75 "a (unitless) from 20 to 80 VWC: 0:0008 m3=m3 (0.08% VWC) from 0 to 50% VWC
 
Accuracy: "a: _1 "a (unitless) from 1 to 40 (soil range), _15% from
40 to 80 (VWC) Using Topp equation: _0:03 m3=m3(_3% VWC) typical in mineral soils that have solution electrical conductivity < 10 dS/m Using medium specific calibration, _0:01 to 0:02 m3=m3 (_1 to 2% VWC) in any porous medium.Temperature
Range: -40 to 80 ºC
Resolution: 0.1 ºC
Accuracy:±1 ºC
General
Dimensions: 10 cm (1) x 3.2 cm (w) x 0.7 cm (d)
Prong Length: 5.2 cm
Dielectric Measurement Frequency: 70 MHz
Measurement Time: 150 ms (milliseconds)
Power requirements: 3.6 to 30 VDC, 0.3mA quiescent, 10mA during 150 ms measurement
Output: SDI-12 ONLY
Operating Temperature: -40 to 80 ºC
Connector Types: 3.5 mm (stereo) plug or stripped & tinned lead wires (Pigtail)
Cable Length: 5 m standard; Maximum 75 m. Please contact if you need longer cable lengths.
 
2.2 Background
In 2006, MT-10 incorporated research from its EC-5 volumetric water content sensor into the EC-TM, a sensor that measures volumetric water content and temperature. The new MT-10 uses the same theory as the EC-TM, but has an improved calibration procedure and SDI-12 capabilities the MT-10 utilizes a five point dielectric calibration to provide more accurate dielectric permittivity measurements than the previous EC-TM. In 2014, we changed the over molding on the sensor circuitry from macro melt to polyurethane to extend the life of the sensor.
 
 
3 Theory
3.1 Volumetric Water Content
The MT-10 sensor uses an electromagnetic field to measure the dielectric permittivity of the surrounding medium. The sensor supplies a 70 MHz oscillating wave to the sensor prongs that charges according to the dielectric of the material. The stored charge is proportional to soil dielectric and soil volumetric water content. The MT-10 microprocessor measures the charge and outputs a value of dielectric permittivity from the sensor.
3.2 Temperature
The MT-10 uses a surface-mounted thermistor to take temperature readings. The thermistor is underneath the sensor over mold, next to one of the prongs, and it reads the temperature of the prong surface. The MT-10 outputs temperature in ºC unless otherwise stated in Data Trac 3 or ECH2O Utility preferences file. It is important to note that if the black polyurethane over mold of the sensor is in direct sunshine, the temperature measurement may read high. We do not recommend that the sensor be installed with the over mold in the sun.
Note: Do not install the sensor with the over mold exposed to the sun.
4 Calibration
4.1 Dielectric Permittivity
MT-10 factory calibrates each MT-10 sensor to measure dielectric permittivityaccurately in the range of 1 (air) to 80 (water). The unprocessed raw values reported by the MT-10 in standard serial communication have units of "a _ 50. When used in SDI- 12 communication mode, the unprocessed values have units of "a (for MT-10 board versions R2-04 and older, units are, "a _ 100).
4.2 Mineral Soil Calibration
Numerous researchers have studied the relationship between dielectric permittivity and volumetric water content (VWC) in soil. As a result, numerous transfer equations that predict VWC from measured dielectric permittivity. You are free to use any of these various transfer equations to convert raw dielectric permittivity data from the MT-10 into VWC. If you choose the mineral soil calibration option in MT-10's ProCheck reader, DataTrac 3, or ECH2O Utility, they convert raw dielectric permittivity values with the Topp equation (Topp et al. 1980s).
Our tests show that in a properly installed MT-10 sensor in a normal mineral soil with saturation extract electrical conductivity < 10 dS/m, the Topp equation results in measurements within _3% VWC of the actual soil VWC. If you require more accurate VWC than _3%, are working in a soil with very high electrical conductivity, or non normal mineralogy, then it may be necessary to conduct a soil specific calibration for your MT-10 sensor to improve the accuracy to 1 to 2% for any soil. For more information on how to perform your own soil specific calibration, or to have MT-10's calibration service performone for you.
Calibration in Non-Soil Media
MT-10 has performed calibrations with the MT-10 in several nonsoil growth media. The following are suggested calibration equations for some common materials. Potting Soil
MT-10 continually develops additional calibration equations for various other growth media as opportunities arise.
The MT-10 can accurately read VWC in virtually any porous medium if a custom calibration is performed.
5 Connecting Sensors
MT-10 designed the MT-10 sensor for use with our Em50 series data loggers or the ProCheck handheld reader. The standard sensor (with a 3.5 mm \stereo plug" connector) quickly connects to and is easily configured within a MT-10 logger or ProCheck. The MT-10 sensor incorporates several features that also make it an excellent sensor for use with third party loggers. Customers may purchase the sensor with stripped and tinned wires (pigtail) for terminal connections.
The MT-10 sensor comes standard with a five meter cable. Customers may purchase sensors with custom cable lengths for an additional fee (on a per-meter fee basis). Obtaining custom length cables eliminates the need for splicing the cable (a possible failure point).