Spectrum fieldscout TDR 300 Product Manual

®

TDR 300

Soil Moisture Meter

PRODUCT MANUAL

Item # 6430FS

CONTENTS

General Overview 3
Shaft Dimensions 4
Computer Interface/Changing Batteries 5
Identifying the Correct Com Port 6
Meter Operation 7
Meter Calibration 10
Taking Readings 11
Field Scout Software Toolbar 14
Meter Settings 16
Connecting to a GPS Unit 18
Data Files 20
Volumetric Water Content Measurements 22
Relative Water Content 24
Specifications 26
Appendix 1: Time Zone Corrections 27
Appendix 2: Soil-Specific Calibration 28
Appendix 3: Troubleshooting 30

This manual will familiarize you with the features and operation of

your new FieldScout

this manual thoroughly before using your instrument. For customer

support, or to place an order, call Spectrum Technologies, Inc. at

between 7:30 am and 5:30 p.m. CST

TM

TDR 300 Soil Moisture Meter. Please read

[phone] or [phone]

FAX [phone]

e-mail: [e-mail]

www.specmeters.com

2

General overview

Thank you for purchasing the Field ScoutTM TDR 300
Soil Moisture Meter. This manual describes the fea­tures and operation of the meter.

Soil moisture is a critical and potentially highly vari­able component of the soil environment. Time-domain
reflectometry is a proven technology for quickly and
accurately determining volumetric water content
(VWC) in soil.

The Field Scout’s shaft-mounted probe allows the user
to easily and rapidly take many measurements. The
user can quickly transition between taking VWC read­ings in standard and high-clay mode. The meter’s
built-in data logger can record data from several sites
and eliminates the need to record data manually.
Through the software (included) the user can download
the data, change the logger settings and program the
logger to record relative water content at multiple sites.

Contents

Your TDR300 shipment includes the following compo­nents:

- TDR 300 meter (in retracted position)

- Carrying case

- Wrench for tightening rods

- 4 AAA batteries

- Field Scout software installation CD

- Gray PC interface cable

Note: TDR rods are sold separately

3

Shaft dimensions

The following are the dimensions of a fully extended
shaft. It is possible to reduce the length of the meter by
2” (5cm) by adjusting the lower half of the shaft.

14”

4”

Meter

16”

20”

3.0”

3.1”

1.3”

4

Computer Interface/

Changing Batteries

Software Installation

Insert the CD for Field Scout software into your PC’s disk
drive. If auto-start is not enabled on your computer, select
Run from the Start menu and type D:\Setup.exe
(Substitute the appropriate drive letter for your CD drive).
Click OK and follow the instructions on the screen.

TDR 300
data port

The data port on the underside of the TDR 300 meter
(shown above) can be accessed by removing the plastic
screw. It is through this port that the meter is connected
to either a PC or to a GPS unit. The meter must be turned
off before attempting communication with the software.

Connecting to a PC

The Field Scout software comes with a gray PC interface
cable. This cable connects to the 9-pin serial port of your
computer and to the meter’s computer port. The meter’s
configuration can be modified by clicking on the Meter

Settings button (see Meter Settings, p. 16). The Com
Port, Meter Type, Download, Clear Memory and Me-
ter Settings buttons are explained in the Field Scout Soft-

ware Toolbar section (p. 14).

Changing the batteries

The battery compartment is accessed by removing the me­ter’s face plate. The meter is powered by AAA batteries.

When installing new batteries, note whether the bat­teries immediately feel hot to the touch. The battery
has been short-circuited and should be replaced.

5

Identifying the

Correct Com Port

The computer
Communications Port to
which the PC-3.5 serial
cable is connected can be
identified by using a
paper clip.

1. Disconnect the serial
cable from the meter.

2. To bring up the Port Selection screen, click on the
Com Port Button, select the com port to be tested and
click the Port Test button. Click the Test Port Now
button. If the message “Connection OK” is displayed,
another device (such as a modem) is probably connected
to that port. If the message “No Connection” is displayed,
this port may be the one connected to your serial cable and
you can proceed to the next step.

3. Place a paperclip on the end of the serial pin so that it
touches both the tip of the pin and the metal area between
the two black rings. Again click on the Test Port Now
button. If the message “Connection OK” now appears,
this is the com port connected to your serial cable.

paper clip
or wire

NOTE: The dataloggers do not short-circuit the serial pin.
Therefore, when the Test Port button is clicked while the
meter is connected, the “No Connection” message will be
displayed.

6

Meter Operation

ON

memory has been used and, if the logger was enabled in
the software, whether the GPS signal was found. If a GPS
signal is found, latitude and longitude data will be in­cluded in the data file. The screen will then display the
most recently used MODE screen.

Logger 75% Full
GPS=Yes DGPS=No

Sample meter power-up screens with datalogger
enabled: left screen indicates GPS signal was found.

The ON switch turns the meter/
datalogger on and off. When the meter is
turned on, it will display the battery
status for 3 seconds. For the next 3 sec­onds, it will display how much logger

Logger 75% Full
No GPS Found

If you are using GPS, but the meter doesn’t find the GPS
signal when powering up, the meter will not search for the
GPS signal when taking readings. Turn the meter off and
on so it can look for the GPS signal. Once the signal is
found, GPS information will be included in the data file
until the signal is lost or the GPS unit is disconnected
from the meter.

Note: If the data logger is disabled (see Meter Settings, p.

16), the meter will not seek the GPS signal when it is
powered up. It will, instead, proceed immediately to the
most recently used mode (see MODE button, p. 8) screen.

7

MODE

Pressing the MODE button allows the
user to determine the type of measure­ment that will be taken or select the
length of rods connected to the probe.

Data Collection Modes
Available measurement options are volumetric water con-

MODE

tent (VWC) using the standard or high clay mode (see p.

22), up to two relative water content modes (see p. 24), or
measurement period (in microseconds). Relative water
content options will only appear if they are configured in
the software (see Meter Settings, p. 16). The period meas­urement is available for users interested in performing
soil-specific calibrations (see Appendix 2).

Note: There is not a high clay measurement calibration for
the 1.5” rods. The meter will display dashes if this mode/
rod length combination is selected.

Changing Rod Length

ROD=MED (4.7in)
HIT DEL To Chnge

In order to get accurate volumetric or relative water con­tent (VWC or RWC) readings, the rod length setting must
be correct. In the VWC modes, the currently selected rod
length appears in the lower left corner of the LCD screen.
The options are Turf (1.5”), Short (3.0”), Medium (4.7”),
and L
LCD displays the rod length options screen. Pressing the
DELETE/CLR AVG button will allow you to toggle be­tween the three choices.

ong (7.9”) rods. Press the MODE button until the

Rod Length Options Screen

8

Meter Calibration Mode

CALIBRATION MODE

HIT READ To Cal

Meter Calibration Screen

This mode allows you to calibrate the meter. The cali­bration procedure is performed in air and distilled water
(see Meter Calibration, p. 10). Requires firmware v. 6.5
or greater.

Delete

Clr Avg

When the DELETE/CLR AVG
button is pressed and immediately
released, the last data point will be
taken out of the logger file and
removed from the running aver-

age. Pressing and holding this but­ton will reset the running average but will not affect
data stored on the data logger.

Press the READ button to read the
probe and update the screen values.

READ

Data values, along with GPS or DGPS
information if applicable, are sent di-

rectly to the data logger. If the logger
searches for, but doesn’t find a GPS signal, an error
message will briefly appear in the lower right corner.
In this case, a data point will be stored without the GPS
data. The data point can be cleared from memory with
the DELETE/CLR AVG button (above).

When the data logger is full, the LCD will display the
message “Error: Memory Full”. To resume normal op­eration, the logger memory must be cleared using the
Clear Memory button in Field Scout software (see p.

15)

9

Meter Calibration

The meter has internal calibrations for standard and
high-clay soil types. These calibrations will work for a
large number of soils. However, each meter will have a
small difference in how it responds to identical soil
conditions. This is due to sensor drift or variability in
the electronic components used during manufacturing.
Meters with firmware v. 6.5 or greater allow for adjust­ments to the meter calibration to account for these dif­ferences. Therefore, if two meters are giving slightly
different readings in the same soil, the output of the
meters can be standardized such that the meters can be
used interchangeably. The calibration procedure is as
follows:

1. Use the MODE button to put meter in Calibration
mode (see p. 8). Hit the READ button

2. Hold the meter so the rods are in the air. Press the
READ button and wait until the meter indicates it is
ready.

3. Immerse the rods completely in distilled or de­ionized water. The container should have a minimum
diameter of 3 inches. Press the READ button and wait
until the meter indicates it is ready.

The meter will then show that the calibration is com­plete for that specific rod length. If more than one rod
size is being used, a calibration operation must be done
for each one.

Note: This procedure is different than a soil-specific
calibration (Appendix 2, p. 28) where a unique calibra­tion curve is generated.

10