Decagon Devices 10HS User Manual

Decagon Devices, Inc.

Version: July 7, 2016 — 14:04:38

10HS

Decagon Devices, Inc.

2365 NE Hopkins Court

Pullman WA 99163

Phone: [phone]

Fax: [phone]

Website: www.decagon.com

Email: [e-mail] or [e-mail]

Trademarks

c

2007-2013 Decagon Devices, Inc.

All Rights Reserved

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10HS CONTENTS

Contents

1 Introduction 1

1.1 Warranty . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.2 Seller’s Liability . . . . . . . . . . . . . . . . . . . . . . 2

2 About the 10HS 3

2.1 Background Info . . . . . . . . . . . . . . . . . . . . . 3

2.2 Specifications . . . . . . . . . . . . . . . . . . . . . . . 4

3 Theory 5

4 Installing the Sensor 6

4.1 Procedure . . . . . . . . . . . . . . . . . . . . . . . . . 6

5 Connecting Sensors 9

5.1 Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

6 Calibration 12

6.1 Dielectric calibration . . . . . . . . . . . . . . . . . . . 12

6.2 Mineral Soil Calibration . . . . . . . . . . . . . . . . . 12

7 Sample Programs 14

8 Declaration of Conformity 17

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10HS 1 INTRODUCTION

1 Introduction

Thank you for choosing the 10HS soil water content sensor. This
innovative sensor enables you to monitor volumetric water content
of soil accurately and affordably. This manual helps you understand
the sensors features and how to use this device successfully.

There are several ways to contact Decagon if you ever need assis­tance with your product, have any questions, or feedback. Decagon
has Customer Service Representatives available to speak with you
Monday through Friday, between 8am and 5pm Pacific time.

Note: If you purchased your sensor through a distributor, please con­tact them for assistance.

Email:
[e-mail] or [e-mail]

Phone:
509-332-5600

Fax:
509-332-5158

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.

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1 INTRODUCTION 10HS

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.

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10HS 2 ABOUT THE 10HS

2 About the 10HS

The 10HS measures the dielectric constant of the soil in order to find
its volumetric water content (VWC). Since the dielectric constant of
water is much higher than that of air or soil minerals, the dielectric
constant of the soil is a sensitive measure of volumetric water content.
The 10HS has a low power requirement and very high resolution.
This gives you the ability to make as many measurements as you
want (i.e hourly) over a long period of time with minimal battery
usage.

2.1 Background Info

In 2005, the Decagon research team optimized a sensor oscillator fre­quency for very high accuracy soil moisture measurements. The first
sensor to incorporate the new frequency was our EC-5 sensor. The
EC-5 quickly became Decagon’s most popular soil moisture sensor.
The new 10HS sensor uses the same 70 MHz oscillator frequency
as the EC-5, but has a larger soil volume and requires no special
calibration when you use it with other systems. The 10HS has two
features that distinguish it from the EC-5.

• The on board voltage regulator allows you to power the sensor
with a wide range of excitation voltages (3 to 15 VDC) without
changing the calibration.

• Large sensing area (1,100 cubic centimeters) that provides a
more representative measurement of soil VWC.

The 10HS sensor runs at the same oscillator frequency that has given
the EC-5 exceptional performance in soils (Kizito et.al, 2008, Bogena
et. al, 2007). We recommend the 10HS sensor for mineral soil appli­cations where soil heterogeneity is a concern. However, we continue
to recommend the smaller EC-5 sensor for soilless substrate appli­cations or applications where VWC measurements on smaller scales
(e.g. near surface measurements, laboratory column studies, green­house applications) are desired.

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2 ABOUT THE 10HS 10HS

2.2 Specifications

Range:

Apparent Dielectric Permittivity (εa): 1 (air) to 50
Soil Volumetric Water Content (V W C) : 0 to 0.57 m3/m

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(0 to 57%VWC)

Accuracy:

εa: ± 0.5 from εaof 10 to 50 (VWC)

VWC: With standard calibration equation, ±0.03 m3/m3(±
3% VWC) typical in mineral soils that have solution electrical
conductivity < 10 dS/m

Note: With soil specific calibration, ± 0.02 m3/m3(± 2%
VWC) is typical in any soil.

Resolution:

εa: 0.1 from εaof 1 to 30, 0.2 from εaof 30 to 50

VWC: 0.0008 m3/m30.08% VWC) in mineral soils from 0 to

0.50 m3/m3(0 to 50% VWC)

Measurement Time: 10 ms (milliseconds)

Power Requirements: 3 VDC @ 12 mA to 15 VDC @ 15 mA

Output: 300 to 1,250 mV, independent of excitation voltage

Operating Temperature: 0 to 50◦C

Survival Temperature: -40 to 50◦C

Connector types: 3.5 mm stereo plug or stripped and tinned leads.

Cable length: 5 m standard; custom cable lengths up to 40 m avail-

able upon request

Data Logger Compatibility (non-exclusive):

• Decagon: Em50, Em50R, Em5b, ProCheck handheld reader.

• Campbell Scientific: CR10X, 21X, 23X, CR850, 1000,

3000, etc

• Other: Data acquisition systems capable of switched 3 to
15 V excitation and single ended voltage measurement at
≥ 12 bit resolution

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