Pessl Instruments Metos iMETOS SoilGuard User manual

1
iMETOS
SoilGuard
Portable Soil Moisture Meter
PRODUCT MANUAL
VERSION 1.0, 07-2021

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General overview 3
Specications 4
Product dimensions 5
Meter Care 6
Button functions 7
Meter operation 8
Display screens 9
Setting Date/Time 11
GNSS (location) Settings 11
GNSS Location: Features, Use and Optimization 12
DataLogs 14
Data Upload 15
Using the SoilGuard uploader 15
Using the web platform 15
Data visualization 16
Web Portal data visualization 16
Mobile app data visualization 17
Maintenance 18
Volumetric Water Content (VWC) 19
Electrical Conductivity 20
Appendix1:Soil-SpecicReadingCorrelation 21
Appendix 2: Troubleshooting 22
Appendix 3: Updating Device Firmware 23
Appendix4:Calibration 24
Glossary 25
Warranty 26

3
General overview
Thank you for purchasing the iMETOS SoilGuard soil moisture meter. This manual describes the meter’s general
features and operation. The iMETOS SoilGuard solution is the perfect mobile tool for measuring soil moisture,
electrical conductivity (EC) and soil surface temperature.
Its handling facility allows users - from agricultural to greenkeeping activities - to take multiple in-eld
measurements within one day. Data is displayed on the device screen or via data import. A USB stick should
be connected to the SoilGuard uploader, while data can be visualized either on your smartphone or on the web
portal (TurfClimate), while data will be available for both applications, once uploaded. SoilGuard uploader: iOS
or Android versions; TurfClimate app: iOS and Android.
Together with the permanent readings and the mobile application and the spot readings from iMETOS
SoilGuard you will get a complete picture of the golf course’s moisture prole, the temperature readings on
the various points of the green in the form of color-coded sample markers for easier understanding and
further decision-making.
Key features:
• Easy to use, mobile and rapid measurements
• Easy-readable backlit display to see the values immediately
• Provides up to 50,000 measurements, all with their specic GPS coordinates
• Has an ergonomic design with a telescoping tubular frame
• Provides accurate measurements of:
- soil moisture (Volumetric Water Content %)
- electrical conductivity (salts)
- soil surface temperature
Contents
Includes the following components:
• iMETOS SoilGuard meter (in collapsed position)
• Carrying case
• 4 AA batteries already installed

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Specications
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)

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Product dimensions

6
Meter Care
The SoilGuard meter will function properly under normal conditions experienced in eld 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 of time (ie: between seasons).
Battery life
If the battery level is low or a battery is inserted incorrectly, the low battery icon appears on the screen briey
then, the display will power o.
Battery life is aected by the enabled features, accessories connected, and the
frequency of use. If not needed, the Bluetooth, GNSS Location and backlight
features can be disabled individually. The backlight can be disabled or set to
AUTO mode which allows enough time to see new measurements and then will
power down the backlight to conserve the battery life.

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Button functions
ON/OFF | BACK button
• Press briey to power on.
• Press and hold to power on and stay on the startup screen.
• Press for 2 seconds to power o.
• Press briey within a menu to return to the prior screen.
MENU | SELECT button
• Press to enter available menus.
• Press to select or conrm a menu selection.
DELETE | UP button
• Press to move up within the menu.
• Delete last measurement from the running average, counter, and its entry from the
internal data log.
READ|DOWNbutton
• Press to move down within the 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 Settings Menu.
Probe base, thumb screw, and probe rods
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 and alter the reading accuracy.
Caution: Exercise care not to bend or damage the rods.
3. Press the READ button and observe the change in results on the top display.

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Display screens
The iMETOS SoilGuard has 3 main display screens:
• Startup
• Reading (shown below)
• Settings Menu
Startup Information screen
Initially displayed after rst powered on.
• Displays model, serial number and rmware version.
• Press and hold ON/OFF|BACK button to remain on this screen.
Readingscreen
Displays the last measurement, EC in milliSiemens per centimeter, temperature, selected rod type, selected
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.
Sample view from iMETOS SoilGuard
Settings Menu screen
Used for changing device features, setting rod length and working with log les.
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 elds or turf greens.

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Clear Logs*: Erases data logs from internal memory.
Save to USB*: Transfers data logs to a USB ash drive if attached.
Backlight: Sets the LCD backlight: ON, OFF, AUTO. In AUTO mode, the backlight will shut o 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 SoilGuard ™ Mobile app (See p. 20).
Sound: Enable or disable beep for audible feedback.
Temp Source: Changes displayed temperature from the Soil Sensor to the IR Sensor (optional).
Temp Units: Fahrenheit or Celsius scale.
Moisture Type: Selects displayed moisture mode VWC%, Period, or TDR 300.
• VWC%: Volumetric Water Content with EC compensation.
• Period: Raw sensor reading in microseconds (us).
• TDR 300: VWC without EC compensation
EC Units: EC value (mS/cm) or Salinity Index (see p. 25).
Auto-O:Power o delay: 15, 30, 45, 60 minutes.
Current Date, Current Time: Displays or changes current values. See p. 13 for details.
Timezone: Oset from Greenwich Mean Time. As the oset changes, the Time and Date will update.
Daylight Savings: ON or OFF.
Calibration*: Overrides factory calibration. See Appendix
Clear User Calibration: Clears the user applied calibration back to factory settings
Factory Defaults*: Resets menu settings and counter to the factory default value.
About: General information (Model and serial number, rmware versions for display and sensor).
RodLength None Temp Source Soil Sensor
Soil Type Standard Moisture VWC
Backlight, GNSS, Bluetooth Disabled EC units mS/cm
Sound On Auto-O 15 minutes
Temperature Fahrenheit Time Zone GMT

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Setting Date/Time
GNSS (location) Settings
By default, the iMETOS SoilGuard gets the date and time from the satellite signal. These values are displayed
in the Settings Menu. The date and time can also be set manually. When the time and date are set manually,
they will override the default value.
Note: When the batteries are removed, the date/time are reset and the meter resumes getting this
information from the satel-lites.
Updating the Date and Time
1. Press the MENU|SELECT button to get to the Settings Menu.
2. Press the UP or DOWN arrows to navigate to either the Cur-rent Date or Current Time option.
3. Press the MENU|SELECT button to access the Time/Date up-date screen.
There are 3 options:
A. Press the READ|DOWN button to download an update from the GNSS satellites. Proceed to an area
with a good view of the sky and press the Menu/Select button to initiate the process.
B. Press the DELETE|UP button to set the date and time manu-ally. The current settings will be
displayed. Use the UP and DOWN arrows to adjust the highlighted selection. Press the MENU|SELECT
button to conrm and proceed to the next pa-rameter. After pressing the MENU|SELECT button to set
the minutes, the display will return to the Reading screen.
C. Press the ON/OFF|BACK button to return to the Settings Menu without making any change.
GNSS Location adds the ability to log global position coordinates with measurements to aid in irrigation
mapping of crops and turf greens. Location references are stored with the measurement in the data log and
can be uploaded to the cloud through the SoilGuard Uploader mobile app option.
The following menu settings apply to and eect the GNSS location feature:
GNSS Location
Enabled: Measurements will include global position coordinates of the meter position in the data log and\or
Turfclimate App.
Disabled: No location coordinates appear in the Data Log. The Turfclimate app measurements will include the
global position of the mobile device running the app.
GNSS Power Save
Enabled: After periods of inactivity, the GNSS receiver will be placed in standby to improve battery life. The
receiver resumes after the next read button press. A brief pause may be noticed as the receiver resumes
operation.
Disabled: GNSS receiver will remain on for faster measurements. It is recommended to keep disabled during
the rst few days of use to im-prove accuracy and mapping.
GNSS Use QZSS
Enabled (Default): Improves location accuracy in Australia, Banga-lore, Guam, Hawaii, Japan, Singapore and
surrounding areas.
Disabled: Can improve location referencing time when outside of the referenced regions.

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GNSS Location: Features, Use and Optimization
When enabled, the GNSS Location feature provides active location referencing information to aid in
measurement mapping.
HDoP: Actively transitions from a high to low value as the level of precision improves. It may increase in value
if conditions degrade. Values typically range between 9.99 to as low as 0.2. The value will appear blank until
satellites in range are received and precision is calculated.
Sats: Active number of satellites used for position and location measurements. The value will increase from
00 as more satellites are received and used.
LocationReferenceArrowIcon:
Transitions with changes in conditions, available satellites, and higher levels of precision are reached.
Blank icon - GNSS feature is enabled and not ready for location referencing of
measurements. Measurements made with this icon will not have a geo-referenced
location.
Partially Shaded - HDoP level is high and the satellite count is low. Measurements
will have geo-referenced coordinates with a low level of accuracy (< 10m typical).
Dark Shaded - High satellite count without supplemental aug-mentation.
Measurement location accuracy will depend on HDoP and Sats count.
Dark Shaded with Blank Dot - Low Satellite count with supple-mental augmentation
available to improve accuracy. Measure-ment location accuracy will depend on
HDoP.
Dark Shaded with crosshair - High satellite count with supple-mental augmentation
available to improve accuracy. Measure-ment location accuracy is optimal (< 2.5m)
and will depend on HDoP.
Clock icon; HDoP: Z.zz - GNSS Power Save has placed the receiver in standby mode.
Press READ|Down button to resume. Note: First reading will have a slight delay.

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Initial Use:
During the rst three days of use, the meter’s GNSS receiver will build an internal satellite record used for
tracking and accuracy. Accuracy during this time may appear low, will depend upon the accuracy of available
satellite systems, and can vary to within 10 meters.
After the third use, the satellite record will be complete; the speed and accuracy of the location referencing
will be at its best as the record is synchronized with the area the meter is being used.
Preparing for measurements:
Expect the rst georeferenced location to take place within a minute or so of operation on a clear day.
A minimum of 4 received satellites are necessary for a location x. Achieving 10 or more satellites will yield
better position data.
ForBestResults:
• Keep the meter active for more than 6 minutes per session.
• Avoid powering o the meter between measurement locations with-in a use session. The meter will
acquire the most satellites and better position data when remaining on for longer periods of use.
• Position the meter upright (probes facing down) while moving between locations to allow continued
satellite tracking.
• When positioning the meter for a measurement, observe the display for a dark arrow icon, low HDoP
value, and high Sats number.
• If possible, keep the meter stationary in position for a moment before pressing the read button.
• For faster results, disable GNSS Power Save to keep the receiver active. When enabled and the meter has
been inactive, GNSS receiver may take a few seconds to resume from standby.
• Avoid using close to structures and dense tree canopies which can block satellite signals.
• Adjust standing position to acquire best icon shading and satellite count prior to pressing the read
button. Simply standing to the side of the meter may make satellites visible and change the count and
precision.

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Data Logs
Before downloading data to the USB, the USB-OTG adapter oered by Pessl Instruments has to be formatted
before using it the rst time for downloading data from your SoilGuard device.
• Simply connect it to your computer, go to the corresponding drive and format it. In Windows 10: right-
click on the drive, click format.
• Select the FAT32 le system and press start.
Downloading Data Logs to a USB Flash Drive
1. Remove the protective dust cover from the USB port.
2. Connect the ash drive to the meter’s USB port. Note: A USB cable is not required or recommended.
3. Press the MENU|SELECT button to open the Settings Menu.
4. Press the READ|Down arrow button to reach the Save to USB option.
5. Press the MENU|SELECT button to select the option.
6. When the download completes, “Logs Saved!” will appear on the LCD screen.
7. Remove the ash drive from the USB port and replace the dust cover.
The data will be saved to the ash drive as a comma-separated text le (.csv) named with the serial number as
the lename. These les can be opened with common text-editing or spreadsheet software. If a previous data
le exists on the ash drive with the same lename, it will be overwritten. Be sure to save any existing data logs
on the ash drive prior to saving a new le.
Erasing the internal Data log
1. Press the MENU|SELECT button to open the Settings Menu.
2. Press the READ|Down arrow button to reach the Clear Logs option
3. Press the MENU|SELECT button to select the option.
4. Press MENU|SELECT button again to start the process or the ON/OFF|BACK button to return back to the menu.
Data Collected
The following information is logged with each reading:
Time,VWC%,Period,EC,Temp_Soil,Temp_Soil(F),Temp_IR,Temp_IR(F),Latitude,Longitude,Satellites,
Fix,RodLength,SoilType,VWCMode,HDoP
• Time: MM/DD/YYYY HH:MM:SS based on the GMT oset selected in the Timezone option, Data Logs
• VWC%: Volumetric Water Content based on the Moisture Type setting
• Period: Raw Period result (after any applied user calibration)
• EC: Electrical Conductivity in milliSiemens per centimeter
• Temp_Soil: Soil temperature sensor reading in degrees Celsius
• Temp_Soil(F): Soil temperature sensor reading in degrees Fahrenheit
• Temp_IR: InfraRed soil temperature sensor reading in degrees Celsius (if equipped)
• Temp_IR(F):InfraRed soil temperature sensor reading in degrees Fahr-enheit (if equipped)
• Latitude, Longitude: Geo-referenced coordinate acquired in decimal degrees format. Note: A negative sign
may appear indicating South or West coordinates.
• Satellites: Number of satellites used in geo-referenced location
• Fix: GNSS location x level; 0 - unreferenced, 1 - xed reference, 2 - x with additional accuracy correction
(SBAS, WAAS, EGNOS)
• RodLength:Depicted as L: Long (8”), M: Med (4.8”), S: Short (3”), T: Turf (1.5”), 1: 0.5” Spacer, and 2: 1.0” Spacer
• Soil Type: character depicted as S: Standard, H: Hi-Clay, and D: sand.
• VWC Mode: depicted as V for EC compensated or 3 for non-compensated (TDR-300).
• HDoP: Horizontal Dilution of Precision value achieved with the GNSS coordinates

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Data Upload
There are 2 ways to import the data: either using SoilGuard
uploader (mobile app) or TurfClimate (web platform).
Using the SoilGuard uploader
• For the data upload, a user account is required. You can
register an account for free here: https://turfclimate.com/ or
https://ng.eldclimate.com/auth/login.
• Insert the USB sticker to the mobile phone
• For iOS phones, an Apple Lightning to USB camera cable is
needed to connect the USB stick for the upload due to Apple
security reasons.
• Open the SoilGuard uploader app and press ”Upload data”
Using the web platform
https://turfclimate.com or https://ng.eldclimate.com/auth/login, data can be uploaded by clicking on the
top-right corner User menu -> Data upload.
Insert the USB sticker to the
mobile phone.
On TurfClimate select Data Upload and select the .csv le from the USB driver.

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Data visualization
A prerequisite for sample data visualization on the TurfClimate App is the denition of a crop zone
covering your samples using the web portal https://turfclimate.com/. To create a crop zone please follow the
instructions on the tutorial https://www.youtube.com/watch?v=KGb5z6Ldu-g.
After data upload to the server, data can be visualized on the mobile app or the TurfClimate web portal. Both
environments are dedicated for greenkeepers and farmers with iMETOS devices (SoilGuard, MobiLab, Dualex).
Web Portal data visualization
For the web portal application, SoilGuard data can be visualized on a raw-data table. There are two ways to
check your SoilGuard data: (1) In Fieldclimate data is visualized by clicking on the station list (top-right icon).
(2) additionally if you have a FarmView license data is visualized by clicking on the station or cropzone list (top-
right icons).
Users with a Fieldclimate account can see the data only in a table.
Features are listed below:
• Sort data per column
• Select devices on the station list (TurfClimate) or on the cropzone list (in case of FarmView license)
• Download data and export as Excel le
• Select data via customizable dates
• Filters to select the correct data
When having a FarmView license, SoilGuard users can also visualize its data within CropZone boundaries, to
compare soil moisture conditions within dierent dates and locations, plus the right moment to irrigate, how
much and Satellite imagery.
Draw the boundaries of your cropzone with a FarmView license
and get access to premium services.

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Mobile app data visualization
For the mobile app, SoilGuard data or other devices such as Dualex and MobiLab can be visualized in-eld or
remotely. Features are listed below:
• Color-coded data based on healthy conditions for each parameter
• Date and device lters
• Individual/clickable data samples for data visualization
• Data selection for SoilGuard moisture content, or MobiLab Soil sampling, Dualex nutrients, MobiLab
Plant Sap, within other multiple options.
• In the case of FarmView license, users have access to cropzones (data monitor in space and time), device
lters, and the possibility to choose a value of interest from each device.
Data visualization in TurfClimate mobile app.

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Maintenance
Separating the Display and Sensor:
1. Remove the probe rods from the sensor base.
2. Flip the display so the backing plate is facing up.
3. Remove the 4 screws on the base using a Philips screwdriver.
4. Gently separate the display from the base plate. Note: The sensor cable connected in the center has
limited cable length.
BatteryReplacement:
1. Follow the steps in DisplayandSensorRemovalto access the batteries.
2. Install four new AA batteries observing correct polarity by referencing the (+) positive and (-) negative
labels.
3. Follow the procedure on the next page to reinstall the display.
DisplayRemoval:
1. Follow steps for DisplayandSensorRemoval to access the display and cable connections.
2. Remove the foam spacer and unplug the sensor cable connector from the jack (g. 1). If an IR temperature
sensor is connected, disconnect this plug as well. Do not discard the foam spacer.
Display Installation:
1. Follow the procedures for DisplayRemovalto access the display and cable connections.
2. Re-connect the sensor cable to the 3.5mm connector on the back of the display module.
3. Insert the foam spacer back into place behind the sensor cable. The split end ts around the sensor cable
molding.
4. If equipped with the IR temperature sensor option, attach it to the smaller diameter connector.
5. Guide the excess cable length back down through the base plate.
6. Align the arrows on the base and display in the same direction. The USB port should face the same side as
the serial number label.
7. Tighten the four mounting screws.
PLUG
CABLE
Figure 1. Sensor connection to the display.

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SensorBlockRemoval/Replacement:
1. Follow steps for Display Removal to access the cable connections.
2. Remove the thumb screw lock bolt that joins the lower probe
base to the upper shaft.
3. Separate the probe base from the shaft (g. 2).
4. Feed the cable from the replacement probe base through the
upper shaft. Attaching a string fed down from the top can aide in
the process of cable reconnection.
5. Follow the procedure for Display Installation to complete the
replacement. Figure 2. Shaft interface
Volumetric Water Content (VWC)
The ratio of the volume of water in a given volume of soil to the total soil volume expressed as a decimal or a
percentage. Three soil moisture levels of most importance can be dened as follows:
• Saturation: All soil pores are lled with water. The VWC will equal the percent pore space of the soil.
• Field Capacity: The condition that exists after a saturated soil is allowed to drain to a point where the pull
of gravity is no longer able to remove any additional water.
• Permanent Wilting Point: The highest moisture content at which a plant can no longer extract water from
the soil.
Additionally, we can dene Plant Available Water as the amount of water between Permanent Wilting Point and
Field Capacity. One rule of thumb is that irrigation should be initiated when half the Plant Available Water has
been depleted.
TimeDomainReectometry(TDR)
The speed of an electromagnetic wave along a waveguide in soil is dependent on the bulk dielectric permittivity
(ε) of the soil matrix. The fact that water (ε = 80) has a much greater dielectric constant than air (ε = 1) or soil
solids (ε = 3-7) is exploited to determine the VWC of the soil. The VWC measured by TDR is an average over the
length of the waveguide.
The sampling volume is an elliptical cylinder that extends approximately 3 cm out from the rods. The high
frequency signal information is then converted to volumetric water content. High amounts of clay or high
electrical conductivity (EC>2 mS/cm) will attenuate the high-frequency signal and aect the reading displayed by
the meter. Very high organic matter content will similarly aect the VWC reading.

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Electrical Conductivity
The SoilGuard uses EC readings obtained from the same probes used to measure VWC. To improve the VWC
measurement accuracy, EC is factored out of the VWC reading. This is a key advantage over its predecessor.
The value measured is an average for the entire depth sampled. EC is expressed in units of mS/cm. The EC
measured by an electrode is dened as the bulk EC.
The salinity level of soil is an important component of irrigation and nutrient management. The source of
soil salts ranges from the original parent material, additions from natural sources, and management activity.
High salt concentration in the soil has a negative eect as plant roots cannot bring in sucient soil moisture.
However, fertilizer exists as salt ions in that same soil solution. Low salt levels can result in plants not getting the
nutrients needed.
Direct measurement of salt content can only be done by subjecting a eld sample to laboratory analysis.
Fortunately, the electrical conductivity (EC) is a function of the dissolved salts in the soil. This proxy
measurement is possible because, as salts dissolve into the soil, they dissociate into ions which conduct
electricity.
Salinity Index
The TDR also has the option to report EC in the form of the Salinity Index. The salinity index is dened as the
ratio of the bulk EC to the volumetric water content (expressed as a decimal). For example, if the bulk EC is 0.25
mS/cm and the VWC is 22%, the Salinity Index would be reported as 1.14 (0.25 ÷ 0.22 = 1.14). Therefore, the
Salinity Index combines VWC and EC (corrected for temperature) into a parameter that will be less dependent on
the sub-saturated water content.
The TDR measures the bulk EC of soil that may or may not be saturated. As the soil dries, the remaining pore
space solution becomes more concentrated which increases EC. However, reduced water in the pores leads to
a longer and more tortuous path between the sensor electrodes, which decreases EC. The second mechanism
dominates. Bulk EC will decrease as soil moisture decreases. EC measurements made at dierent times are
comparable when the moisture content is the same. This is best observed if the readings are always taken when
the site is at eld capacity - when a saturated soil is allowed to drain to the point where the pull of gravity can no
longer remove any additional water.