METER TEROS 11 User manual

TEROS 11/12

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TABLE OF CONTENTS
1. Introduction..............................................................................................1
2. Operation ...................................................................................................2
2.1 Installation ................................................................................................2
2.2 Connecting................................................................................................. 6
2.2.1 Connect to METER Logger.................................................................6
2.2.2 Connect to Non-METER Logger.........................................................7
2.3 Communication .........................................................................................8
3. System....................................................................................................... 10
3.1 Specifications.......................................................................................... 10
3.2 Components ............................................................................................ 13
3.3 Theory...................................................................................................... 15
3.3.1 Volumetric Water Content .............................................................. 15
3.3.2 Temperature ................................................................................... 15
3.3.3 Electrical Conductivity (TEROS 12 Only) ......................................... 15
3.3.4 Converting Bulk EC to Pore EC (TEROS 12 Only).............................. 15
3.3.5 Pore Water Versus Saturation Extract EC (TEROS 12 Only) ............. 16
4. Service....................................................................................................... 18
4.1 Calibrations ............................................................................................. 18
4.1.1 Mineral Soils................................................................................... 18
4.1.2 Soilless Media ................................................................................ 18
4.1.3 Apparent Dielectric Permittivity..................................................... 19
18225-02
2.15.2019

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4.2 Cleaning................................................................................................... 19
4.3 Troubleshooting....................................................................................... 19
4.4 Customer Support.................................................................................... 20
4.5 Terms and Conditions .............................................................................. 21
References .................................................................................................... 22
Index ................................................................................................................. 23

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1
TEROS 11/12
1. INTRODUCTION
Thank you for choosing the TEROS11 Soil Moisture and Temperature sensor and the
TEROS12 Soil Moisture, Temperature, and Electrical Conductivity (EC) sensor from
METERGroup.
The TEROS11/12 sensors are designed to be installed in mineral soils, many types of
growingmedia, and other porous materials. This manual guides the customer through
thesensor features and describes how to use the sensor successfully.
TEROS 11/12 sensors are accurate tools for monitoring volumetric water content (VWC),
temperature in soil and soilless substrates, and EC (TEROS 12 only). The TEROS11/12
determines VWC using capacitance/frequency-domain technology. The sensor uses a
70-MHz frequency, which minimizes textural and salinity effects, making the
TEROS11/12 accurate in most mineral soils. The TEROS 11/12 uses a thermistor in the
center needle to measure temperature and EC (TEROS 12 only) using a stainless-steel
electrode array.
Prior to use, verify the TEROS11/12 sensor arrived in good condition. METER
recommends testing the sensors with the data logging device and software before going
to the field.