Spectrum Fieldscout TDR 350 User manual

TDR 350
Soil Moisture Meter
PRODUCT MANUAL
Item # 6435

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Thank you for purchasing the FieldScoutTM TDR 350
soil moisture 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 func-
tion of the moisture and salt in the soil and can be fac-
tored out to increase the accuracy of VWC measure-
ments. The meter also measures soil surface tempera-
ture. The user can quickly transition between taking
VWC readings in standard, high-clay, and sand-based
soils.
The TDR 350’s shaft-mounted probe allows the user to
take measurements while standing. The meter’s built-in
data logger eliminates the need to record data manually.
The data points can be viewed with the FieldScout Mo-
bile app that maps out soil measurements using logged
location coordinates. Measurements can also be saved
to an external USB flash drive using the built-in USB
port.
Contents
Includes the following components:
- TDR 350 meter (in collapsed position)
- Carrying case
- 4 AA batteries already installed
General overview
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 use

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CONTENTS
General Overview 2
Specifications 4
Product Dimensions 5
Meter Care 6
Button Functions 7
Meter Operation 8
Display Screens 9
GNSS (Location) Features 12
Setting Date/Time 13
Optimizing Geo-Referenced Measurements 14
Maintenance 16
Data Logs 18
Field Scout Mobile App/SpecConnect 20
Pairing TDR350 with FieldScout Mobile App 22
VWC Measurements 24
Electrical Conductivity 25
Optional Accessories 26
Appendix 1: Soil Specific Reading Correlation 27
Appendix 2: Troubleshooting 28
Appendix 3: Updating Device Firmware 29
Appendix 4: Calibration 30
Glossary 31
CE Declaration of Conformity 32
UK Declaration of Conformity 34
FCC, ISED and other Regulatory Information 36
Warranty 39

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Measurement
Units
Percent volumetric water content (VWC)
Period (raw sensor reading)
Resolution,
Accuracy and
Range
VWC: 0.1% increment ±3.0% @ < 2 mS/cm
0% to Saturation (Saturation is typically around
50% volumetric water)
EC: 0.01 increment ; ± 0.1 mS/cm; 0 - 5 range
Temperature: 0.2 ˚F (0.1 ˚C) increment ; ± 1.8
˚F (± 1 ˚C); -22 to 140 ˚F (-30 to 60 ˚C)
Thermistor based; Infrared Optional
Connectivity USB Type A, Bluetooth Low Energy
(GNSS)
Accuracy Galileo 1m; GPS 3.5 to 7.5m;
GLONASS 2.8 to 10 m;
QZSS 1 m (where available)
WAAS, SBAS, and EGNOS enabled
Power 4 AA alkaline batteries
Log Capacity 50,000 measurements
Display Backlit, high-contrast, graphic LCD
Weight 4.3 lbs. (1.9 kg)
IP Rating Display: IP53, Probe: IP67
Available
Rod
Dimensions
Turf 1.5” (3.8cm)
Short 3.0” (7.6cm)
Medium 4.8” (12.2cm)
Long 8.0” (20.32cm)
Diameter: 0.2” (0.5cm)
Spacing: 1.2” (3cm)
Specifications

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Product dimensions

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The FieldScout TDR meter will function properly under normal
conditions experienced in field use. The sensor block is sealed
and will not be damaged by immersion in water. The display is
not waterproof so it should not be used during heavy rainfall or
left exposed during irrigation events. If the display does get wet, it
should be dried out immediately.
Follow these tips to prolong the life of the device:
- Store in a cool and dry place when not in use.
- Keep the meter and probe rods clean and dry in between uses.
- Remove the batteries if not used for an extended period (ie: be-
tween seasons).
Battery life
If the battery level is low or a
battery is inserted incorrectly,
the low battery icon appears on
the screen briefly then, the dis-
play will power off.
Battery life is affected by the
enabled features, accessories
connected, and the frequency of use. If not needed, the Bluetooth,
GNSS Location and backlight features can be disabled individual-
ly. The backlight can be disabled or set to AUTO mode (p. 10)
which allows enough time to see new measurements and then will
power down the backlight to conserve the battery life.
Meter Care
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

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Button Functions
ON/OFF or BACK button
− Press briefly to power on.
− Press and hold to power on and stay on the logo
screen.
− Press for 2 seconds to power off.
− Press briefly within a menu to return to prior
screen.
MENU or SELECT button
− Press to enter available menus.
− Press to select or confirm a menu selection.
DELETE or UP button
− Press to move up within a menu.
− Delete last measurement from the running aver-
age, counter, and its entry from the internal data
log (see p. 18).
READ or DOWN button
− Press to move down within a menu.
− Press to make a reading from the Reading screen.
− Press and hold to reset the average and count

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Meter Operation
Setting up the meter
1. Pull the clear battery transport tab out of the display unit.
2. If desired, extend the collapsible shaft by removing the thumb
screw (shown above) from the side, grip and extend the lower
shaft to its new position, re-insert the thumb screw, and hand
tighten.
3. Select a set of probe rods, screw in, and tighten them to the
bottom of the probe block.
4. Set the desired user settings in the settings menu. See the Set-
tings Menu (page 10).
Taking Readings
1. Grip the TDR handles to the left and right of the display.
2. Push down on the handles maintaining a steady downward
pressure to drive the rods into the soil until the sensor base is in
contact with the soil surface. Refrain from any back and forth or
side to side movement which can introduce air pockets into the
soil medium which will alter the reading accuracy.
Caution: Exercise care not to damage the rods which could lead
to damage. See Meter Care (page 6).
3. Press the READ button and observe the change in results on
the top display.
Probe base, thumb screw, and probe rods

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Display Screens
The TDR 350 has 3 main display screens;
- Startup (as shown on page 8)
- Reading (shown below)
- Settings Menu (see page 10)
Startup Information screen
Initially displayed after first powered on.
- Displays firmware version information.
- Press and hold ON/OFF|BACK button to remain on this screen.
Reading screen
Measurements from the sensor are displayed on the Reading
screen along with rod type used, soil type, and a reading count
with running average. VWC=0% readings will be displayed but
will not increment the counter or be included in the average.
Press READ to take readings, update Count and the Average.
Indicators:
Battery level icon: upper right corner.
Bluetooth icon: displayed when enabled. A bar appears
through it when not actively communicating.
GNSS location icon: When enabled,
Transitions from clear to dark as a loca-
tion fix is achieved. Crosshatch appears when WAAS/EGNOS in
use.
Sample Reading screen

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Settings Menu screen
Used for changing device features, setting rod length and working
with log files.
Use the arrow buttons to move to the desired option.
Use the MENU|SELECT button to toggle option choices.
Clear Average*: Clears the displayed average and count.
Note: Same as a press and hold of the READ|Down arrow button.
Rod Length: Select the Rod length. See page 4 for options.
Soil Type: Selects the soil type used in measurements:
- Standard: for most mineral soils.
- Hi-Clay: for soils with higher clay content (> 27%).
- Sand: for sand based fields or turf greens.
Clear Logs*: Erases data logs from internal memory.
Save to USB*: Transfers data logs to a USB flash drive if at-
tached.
Backlight: Sets the LCD backlight: ON, OFF, AUTO. In AUTO
mode, the backlight will shut off 5 seconds after a button press
GNSS Location, GNSS Power Save, GNSS Use QZSS: Enable
or disable features related to geo-location capability (see p. 12).
Bluetooth: Enable or disable Bluetooth connectivity to the Field-
Scout™ Mobile app (See p. 20).
Sound: Enable or disable beep for audible feedback.
Temp Source: Changes displayed temperature from the Soil Sen-
sor to the IR Sensor (optional).
Temp Units: Fahrenheit or Celsius scale.