Spectrum Technologies FieldScout TDR 300 Product Manual

TDR 300

Soil Moisture Meter

PRODUCT MANUAL

Item # 6430FS

2

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: Checking VWC Readings 27

Appendix 2: Soil-Specific Calibration 28

Appendix 3: Troubleshooting 30

This manual will familiarize you with the features and operation of
your new Field ScoutTM TDR 300 Soil Moisture Meter. Please read
this manual thoroughly before using your instrument. For customer

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

[phone] or [phone]

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

FAX [phone]

e-mail: [e-mail]

www.specmeters.com

3

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 elim-

inates the need to record data manually. Through the

software (available from Spectrum website) 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

- 4 AAA batteries

- Black PC interface cable

Note: TDR rods are sold separately

General overview

4

Shaft dimensions

1.3”

3.0”

3.1”

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”

20”

16”

Meter

5

TDR 300
data port

Software Installation

The installation program for FieldScout software can be
downloaded from www.specmeters./software. Run the
executable file, FieldScoutSetup.exe, to install the pro­gram.

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

Use the black PC cable to interface with Field Scout soft­ware. 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 Me­ter Settings buttons are explained in the "Field Scout

Software 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 bat-

teries immediately feel hot to the touch. The battery
has been short-circuited and should be replaced.

Computer Interface/

Changing Batteries

6

The computer

Communications
Port to which the

PC-3.5mm serial
cable is connected

can usually be identified by clicking the Com Port button
on the main screen to bring up the Port Selection screen.
It can also be found by using a paper clip. The procedure
is:

1. Disconnect the serial cable from the meter.

2. Bring up the Port Selection screen and click on the
Com Port Button. Select the port to be tested and click
the Test Port button. If the “Connection OK” message is

displayed, another device (such as a modem) is probably

connected to that port. If the “No Connection” message 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 button.
If the “Connection OK” message now appears, this is the
com port connected to your serial cable.

Note: The meters 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.

Identifying the

Correct Com Port

paper clip
or wire

7

Meter Operation

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 memory
has been used and, if the logger was ena-

bled 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.

ON

Logger 75% Full
GPS=Yes DGPS=No

Logger 75% Full
No GPS Found

Sample meter power-up screens with datalogger

enabled: left screen indicates GPS signal was 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.

8

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 con­tent (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

In order to get accurate volumetric or relative water con-

tent (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 Long (7.9”), Medium (4.7”), Short (3.0”),
Turf (1.5”), T-BLK(1.0”), and T-BLK(0.5”) rods. The fi­nal two options are only available for customers that have
purchased the TDR Turf Rod Spacer (item 6435SP). See
p. 17 for further information. Press the MODE button un­til the LCD displays the rod length options screen. Press-

ing the DELETE/CLR AVG button will allow you to tog-

gle between the five choices.

MODE

ROD=MED (4.7in)
HIT DEL To Chnge

Rod Length Options Screen

9

Press the READ button to read the
probe and update the screen values.
Data values, along with GPS or DGPS
information if applicable, are sent di­rectly 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)

READ

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 aver­age. Pressing and holding this but-

ton will reset the running average but will not affect

data stored on the data logger.

Delete

Clr Avg

Meter Calibration Mode

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.

CALIBRATION MODE

HIT READ To Cal

Meter Calibration Screen

10

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 adjust-

ments 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. Because the meter output is par­tially governed by rod length, the calibration should not
be done with rods that are significantly reduces in size
because of wear. The calibration procedure is as fol-

lows:

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.

Meter Calibration