Decagon Devices MAS-1 User Manual

MAS-1

4-20 mA Soil Moisture Sensor

User Manual

Version 2

Decagon Devices, Inc.

2365 NE Hopkins Court

Pullman WA 99163

[phone]

www.decagon.com

[e-mail]

©2011 Decagon Devices, Inc.

All rights reserved.

MAS-1 Soil Moisture Sensor

Contents

1. Introduction . . . . . . . . . . . . . . . . . . . 1

Customer Service and Tech Support . . . . .2

Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Seller’s Liability . . . . . . . . . . . . . . . . . . . . .3

2. About the MAS-1 . . . . . . . . . . . . . . . 4

3. Integrating the MAS-1 . . . . . . . . . . . .5

Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Conventional (PLC) . . . . . . . . . . . . . . . . .6

Non-Conventional . . . . . . . . . . . . . . . . . .6

Testing the Sensor . . . . . . . . . . . . . . . . . . . .9

4. Installing the MAS-1 . . . . . . . . . . . .10

Procedure . . . . . . . . . . . . . . . . . . . . . . . . .10

Orientation . . . . . . . . . . . . . . . . . . . . . . . .11

Removing the Sensor . . . . . . . . . . . . . . . .11

5. Calibration . . . . . . . . . . . . . . . . . . . . .12

Mineral Soils . . . . . . . . . . . . . . . . . . . . . . .12

Potting Soil/Peat . . . . . . . . . . . . . . . . . . . .13

Rock Wool . . . . . . . . . . . . . . . . . . . . . . . .13

6. Troubleshooting . . . . . . . . . . . . . . . . .14

Declaration of Conformity . . . . . . . . . .15

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

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MAS-1 Soil Moisture Sensor

1. Introduction

1. Introduction

Thank you for choosing the MAS-1 4-20 mA Soil Moisture
Sensor. These innovative sensors will enable you to monitor
soil moisture accurately and affordably with a standard 2­wire, 4-20 mA analog interface for use with many data
acquisition and control systems. The MAS-1 can not be used
with the standard Decagon data loggers.

Specifications

Electrical

Interface: Standard 4-20 mA, 2-wire analog transmitter
Supply voltage: 10-32 VDC continuous
Output current: 4-20 mA
Overvoltage protection: Yes
Reverse polarity protection: Yes
Settling time: 4 seconds
Wiring: Red wire: (+) supply
Black wire: (-) output
Shield: Not connected

Measurement

Type: Volumetric water content (VWC)
Range: 0-50% VWC typical
Resolution: Depends on current measurement (data

acquisition) device
Accuracy:
± 4 % VWC with factory mineral soil calibration in a
typical mineral soil;
± 1-2% VWC with medium-specific calibration in most
porous medium

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MAS-1 Soil Moisture Sensor

1. Introduction

Output: 4-20 mA current proportional to VWC
Sensor measurement interval: 1 second

Operating Environment
Temperature: -40 to 50 °C

Physical Properties
Dimensions: 8.9 cm x 1.8 cm x 0.7 cm
Cable: 2 m, 3 wire (22 AWG tinned Red and Black wire, 24
AWG tinned bare wire);
(Custom cable length available upon request)

Customer Service and Tech Support

When contacting us via fax or email, include the following
information: Your MAS-1’s serial number (found on the
white cable label), your name, address, phone and fax
number, and a description of your problem.

Phone:

Call Monday - Friday, between 8 a.m. and 5 p.m. PST.
US and Canada (toll-free):
Outside of the US and Canada:

1-800-755-2751

[phone]

Fax:

[phone]

E-mail:

[e-mail]

.

NOTE

: If you purchased your MAS-1 through a distributor,

please contact them for assistance.

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MAS-1 Soil Moisture Sensor

1. Introduction

Warranty

The MAS-1 has a one year warranty on parts and labor. It is
activated upon the arrival of the instrument at your location.

Seller’s Liability

Seller warrants new equipment of its own manufacture
against defective workmanship and materials for a period of
one year from date of receipt of equipment (the results of
ordinary wear and tear, neglect, misuse, accident and exces­sive deterioration due to corrosion from any cause are not to
be considered a defect); but Seller’s liability for defective
parts shall in no event exceed the furnishing of replacement
parts F.O.B. 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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