Spectrum Technologies Field Scout TDR 350, Field Scout 6435 Product Manual

TDR 350

Soil Moisture Meter

PRODUCT MANUAL

Item # 6435

2

CONTENTS

Shaft Dimensions 4

Specifications 5

Batteries 6

Button Functions 8

Display Screens 10

Meter Calibration 14

Updating Firmware 15

Electrical Conductivity 16

Meter Operation 18

Replacing or Re-attaching the Probe Block 21

Replacing the Display 22

Field Scout Mobile App/SpecConnect 23

Pairing TDR350 with FieldScout Mobile App 25

Data Logs 27

VWC Measurements 29

GPS Status 30

Optional Accessories 31

Appendix 1: Checking VWC Readings 32

Appendix 2: Soil-Specific Calibration 33

Appendix 3: FAQ 35

This manual will familiarize you with the features and operation of

your new Field ScoutTM TDR 350 Soil Moisture Meter. Please read

this manual thoroughly before using your instrument.

3

Thank you for purchasing the Field ScoutTM TDR 350
soil moisture, electrical conductivity and soil surface
temperature meter. This manual describes the meter's
general features and operation.

Soil moisture is a critical, and potentially highly varia-

ble, component of the soil environment. Time domain

reflectometry is a proven technology for quickly and
accurately determining volumetric water content
(VWC) in soil. Electrical conductivity (EC) is a func­tion of the moisture and salt in the soil. The meter also
measures soil surface temperature. The user can quickly
transition between taking VWC readings in standard
and high-clay mode.

The TDR 350's shaft-mounted probe allows the user to
take measurements while standing. The meter’s built-in
data logger can record data from several sites and elimi­nates the need to record data manually. The data points
can be viewed with the FieldScout Mobile app that
maps out soil measurements using logged GPS loca­tions. Measurements can also be saved to a USB drive
that is plugged into the built-in USB port.

Contents

Your shipment includes the following components:

- TDR 350 meter (in collapsed position)

- Carrying case

- 4 AA batteries

Note: TDR rods are sold separately

General overview

4

Shaft dimensions

The following are the dimensions of a fully extended
shaft. It is possible to reduce the length of the meter to
23” (58.5 cm) by adjusting the lower half of the shaft.

38"

19.5"

2.4"

14"

5"

5

Measurement
Units

Percent volumetric water content (VWC)
Period (raw sensor reading)

Resolution

VWC: 0.1% VWC units
EC: 0.01 mS/cm
Temperature: 0.2 ˚F (0.1 ˚C)

Accuracy

VWC: ±3.0% volumetric water content

with electrical conductivity < 2 mS/cm

EC: ± 0.1 mS/cm
Temperature: ± 1.8 ˚F (± 1 ˚C)

Range

VWC: 0% to saturation (Saturation is typi-

cally around 50% volumetric water)

EC: 0 to 5 mS/cm
Temperature: -22 to 140 ˚F (-30 to 60 ˚C)

Power

4 AA batteries

Lithium batteries will optimize battery life

Logger
Capacity

50,000 measurements

Display

Backlit, high-contrast, graphic LCD

GPS

Accuracy < 2.5m

Weight

4.3 lbs. (1.9 kg)

Probe Head

Dimensions

2.4” x 1.4”

(6cm x 3.5cm)

Shaft
Dimensions

Extended Length: 38” (96.5cm)
Collapsed Length: 23” (58.4cm)
Width: 1.4” (3.5cm)

Available
Rod
Dimensions

Turf 1.5” (3.8cm)
Short 3” (7.6cm)
Medium 4.7” (12cm)
Long 7.9” (20cm)
Diameter: 0.2” (0.5cm)
Spacing: 1.2” (3cm)

Specifications

6

Changing the batteries

The TDR 350 requires 4 AA batteries. The battery holder
is on the underside of the display unit. The sensor is at­tached to the display via a cable that is plugged into a
socket between the battery holders. The cable can be
pulled out of and pushed back into the shaft through a

grommet at the top of the shaft.

Do not permanently remove the foam plug. It ensures
the plug does not come detached.

STEPS:

1. Collapse the shaft.

2. Turn the TDR 350 upside down and remove the 4
screws. Open the bottom and separate the display
module from the base plate. This may require pulling

the cable slightly out of the shaft.

3. Install batteries and ensure correct polarity by refer­encing the (+) positive and (-) negative labels at either
end of each slot.

4. Plug the cable connector back into the larger stereo
jack.

5. Mount the display box back onto the base plate. As
you do this, make sure the side with the USB port is
on the same side as the label.

6. Re-attach the 4 screws.

Batteries

plug

grommet

cable

7

Battery life

The battery level is checked every time the display
unit is turned on. If the battery level is low, or if a
battery is inserted incorrectly, this low battery im­age shows on the full screen for about 10 seconds
and then the display will automatically turn off.

In addition to frequency of use, battery life is im­pacted by use of the backlight and GPS receiver. If
not needed, the GPS feature should be disabled.
The backlight can be set to AUTO mode (p. 12).
This allows enough time to see the reading without
unduly taxing the battery. The chart below gives a
rough estimate of the number of readings that can
be taken given certain configuration parameters.

Total Readings

Bluetooth GPS Backlight Alkaline Lithium

ON ON ON 12,000 24,000
ON ON OFF 24,000 35,000

OFF OFF OFF 150,000 225,000

8

Button Functions

Basic Button Operations

ON/OFF or BACK button

Press this button briefly to turn on the
display. The meter will then display
the Data screen (p. 11). To turn the

meter off, press and hold this button

for about 2 seconds.

When in the Settings Menu screen (p. 12), press
this button to return to the Data screen. If you are
in a settings option that requires its own screen,
this button will return you to the Settings Menu
screen

MENU or SELECT button

When in the Data screen, press this but­ton to go to the Settings Menu screen
(p. 12). When in the Settings Menu
screen and on a menu option, press this
button to browse through the different

choices for that specific menu selection.
In some cases, selecting a settings option will take
you to another screen for further action.

9

DELETE or UP button

When on the Data screen (p. 11), press
this button to delete the last measured
data point from the computed Average
and decrement the Count.

When on the Settings Menu screen (p. 12), press

this button to scroll up to the previous menu item.

READ or DOWN button

When on the Data screen, press and
release this button to take a sensor
reading. Press and hold to clear the av­erage and reset the sample count to 0.

When on the Settings Menu screen, press this but­ton to scroll down to the next menu item.

10

Display Screens

The TDR 350 has 3 main display screens;

- Startup Information screen

- Data screen

- Settings Menu screen

Startup Information screen

The Startup Information screen is displayed for

about 2 seconds after the display is turned on.

If desired, the startup screen can be kept on for a
longer duration. While powering up the meter,
press and hold the On/Off/Back button to contin­ue displaying the Startup Device Information
screen. Release the button to proceed to the Data
screen.

11

Data screen

Readings from
the sensor are
displayed on the
Data screen. The
battery level in­dicator appears
in the upper right
corner. The run­ning average and
number of readings included in that average are
shown in the lower right corner. Pressing and
holding the READ button will clear the average
and re-set the counter to 0.

When disabled, the GPS and/or

Bluetooth icons will no longer

be visible. When visible, the
GPS icon will indicate the quali­ty of the GPS fix (p. 29).

When the Bluetooth is enabled
but the TDR is not connected to
a mobile device, the Bluetooth
icon has a bar through it (see
image in data screen at top of
page). When the TDR is con­nected to a mobile device, the bar is removed (see
image to the right).