Sensors probes

The following sections describe the main features and the general usage for all the sensors probes included in the Plug & Sense! Smart Agriculture Xtreme model.
It is important to remark that Smart Agriculture Xtreme is only available in the Waspmote Plug & Sense! line. It is not available for the Waspmote OEM line. Besides, keep in mind that Smart Agriculture Xtreme is not compatible with the former Smart Agriculture or Smart Agriculture PRO models. In other words, the sensor probes described in this Guide are only compatible with Smart Agriculture Xtreme, because its advanced electronics allow these specific sensor integrations (some exceptions are the BME, Ultrasound or Luminosity sensors).
In order to keep this guide as short as possible, some manufacturer information has been omitted. Libelium encourages the reader to visit the manufacturer websites and to spend some time studying all the technical papers and application notes provided for each sensor. Measured parameters on the great majority of Smart Agriculture applications require a deep knowledge of the environmental parameters and, what is more, sophisticated measurement techniques to obtain the best accuracy.
Additionally, Libelium highly recommends carrying out comprehensive laboratory tests before installing the system on the field, as well as proof of concepts on the field during a reasonable period, before going to a real deployment. Thanks to these good practices, the user will have an idea of the platform behavior, which will be very close to reality. Parameters like accuracy over time or battery drain can be only measured with real tests.
Finally, always take into account a maintenance factor for each sensor probe. The environmental conditions could affect the sensor behaviour and accuracy therefore it will become mandatory periodic maintenance for each sensor probe, to watch out things like dirty on sensor probes, measure position or wire connections. The period between these maintenance actions will be different on each application. Contact our Sales department through the next link if you require more information: http://www.libelium.com/contact.

# Non-contact surface temperature measurement sensor probe (Apogee SI-411)

The Non-contact surface temperature measurement sensor probe is able to measure the electromagnetic radiation that every object with a temperature above absolute zero emits, which is used to calculate the surface temperature from a distance. Thanks to this, the temperature of the object's surface is not altered in any way when measuring it.
Figure: The non-contact surface temperature measurement sensor probe (Apogee SI-411)

## Specifications

• Operating environment: -45 to 80 ºC
• Operation humidity: 0 ~ 100% RH (non-condensing)
• Calibration uncertainty (-20 to 65 ºC), when target and detector temperature are within 20 ºC: 0.2 ºC
• Calibration uncertainty (-40 to 80 ºC), when target and detector temperature are different by more than 20 ºC: 0.5 ºC
• Measurement repeatability: less than 0.05 ºC
• Stability (long-term drift): less than 2% change in slope per year when germanium filter is maintained in a clean condition
• Field of view: 22º (half angle)
• Spectral range: 8 to 14 µm; atmospheric window
• Dimensions: 23 mm diameter; 60 mm length
• Mass: 190 g (with 5 m of lead wire)
• Cable length: 5 m

## Measurement process

The SI-411 sensor provides a digital signal using the SDI-12 protocol.
1
{
2
// 1. Declare an object for the sensor
3
Apogee_SI411 mySensor(XTR_SOCKET_A);
4
5
// 2. Turn ON the sensor
6
mySensor.ON();
7
8
// 3. Read the sensor. Values stored in class variables
9
// Check complete code example for details
10
11
12
// 4. Turn off the sensor
13
mySensor.OFF();
14
}
Copied!
You can find a complete example code for reading this sensor probe in the following link: https://development.libelium.com/ag-xtr-01-si-411-sensor-reading/

## Socket

Connect the SI-411 sensor probe to Plug & Sense! Smart Agriculture Xtreme in any of the sockets shown in the image below.
Figure: Available sockets for the SI-411 sensor probe

## Installation

When choosing the distance of the sensor to the object to be measured at the installation of the sensor, it must be taken into account that it has a field of view (FOV) of 22º (half angle), as you can see in the image below.
It is necessary to remove the green protective cover to measure, it is only used to protect the sensor when it is not being used.
Figure: Sensor's field of view
An Angle mounting bracket (Apogee AM-220) can also be used for the installation. This accessory is recommended to mount the sensor on a pole with an outer diameter from 3.3 to 5.3 cm at different angles.
Figure: Angle mounting bracket (Apogee AM-220)
Looking into the above picture, the black plastic part on the right must be facing the pole, while the metal angled part on the left must fix the sensor.
First, attach the accessory to the pole screwing the 2 nuts just enough to hold the accessory to the pole. Keep the 2 washers to avoid the installation loosening.
Then, place the sensor into the accessory, taking into account that the sensor must point towards the desired target.
Finally, adjust the angles by rotating the sensor and hold it into the desired position while the nuts are tightened.
Figure: Angle mounting bracket installation with the SI-411 sensor
You can find the complete sensor manual on the manufacturer's website.

## Application examples

• Plant canopy temperature measurement for plant water status estimation
• Road surface temperature measurement for determination of icing conditions
• Terrestrial surface (soil, vegetation, water, snow) temperature measurement in energy balance studies

## Certificate of calibration

Together with this sensor we provide a calibration certificate in which the manufacturer ensures that the sensor has passed a calibration procedure with traceability to an accredited laboratory.

# Leaf and flower bud temperature sensor probe (Apogee SF-421)

Frost events may happen in plants even though the ambient temperature is not 0 ºC or lower because the canopy temperature can be different than air temperature, this is called radiation frost. The Leaf and bud temperature sensor probe is designed to predict frost events.
Radiation frost occurs when there is a lack of air mixing by the wind near the surface and a negative net long wave radiation balance at the surface.
Figure: Leaf and bud temperature sensor probe (Apogee SF-421)

## Specifications

• Operating temperature: -50 to 70 ºC
• Operation humidity: 0 ~ 100% RH
• Measurement range: -50 to 70 ºC
• Measurement uncertainty:
• 0.1 ºC (from 0 to 70 ºC)
• 0.2 ºC (from -25 to 0 ºC)
• 0.4 ºC (from -50 to -25 ºC)
• Measurement repeatability: less than 0.05 ºC
• Stability (long-term drift): less than 0.02 ºC per year
• Equilibration time: 10 s
• Self-heating: less than 0.01 ºC
• Dimensions: 57 cm length, 2.1 cm pipe diameter, 7.0 cm disk diameter (see image below)
• Mass: 400 g
• Cable length: 5 m

## Measurement process

The SF-421 sensor provides a digital signal using the SDI-12 protocol.
1
{
2
// 1. Declare an object for the sensor
3
Apogee_SI421 mySensor(XTR_SOCKET_A);
4
5
// 2. Turn ON the sensor
6
mySensor.ON();
7
8
// 3. Read the sensor. Values stored in class variables
9
// Check complete code example for details
10
11
12
// 4. Turn off the sensor
13
mySensor.OFF();
14
}
Copied!
You can find a complete example code for reading this sensor probe in the following link: https://development.libelium.com/ag-xtr-02-sf-421-sensor-reading/

## Socket

Connect the SF-421 sensor probe to Plug & Sense! Smart Agriculture Xtreme in any of the sockets shown in the image below.
Figure: Available sockets for the SF-421 sensor probe

## Installation

The shape of the SF-421 sensor is designed to resemble a plant leaf and flower bud and be able to measure radiation frost events. The sensor should be installed near the plant canopy where the radiation frost detection is required.
Figure: SF-421 sensor installation
An Angle mounting bracket (Apogee AM-220) can also be used for the installation. This accessory is recommended to mount the sensor on a pole with an outer diameter from 3.3 to 5.3 cm in different angles.
Figure: Angle mounting bracket (Apogee AM-220)
Looking into above picture, the black plastic part on the right must be facing the pole, while the metal angled part on the left must fix the sensor.
First, attach the accessory to the pole screwing the 2 nuts just enough to hold the accessory to the pole. Keep the 2 washers to avoid the installation loosening.
Then, place the sensor into the accessory, taking into account that the sensor must point towards the desired target.
Finally, adjust the angles by rotating the sensor and hold it into the desired position while the nuts are tightened.
Figure: Angle mounting bracket installation with the SF-421 sensor
You can find the complete sensor manual on the manufacturer's website.

## Application examples

• Leaf and bud temperature estimates in cropped fields, orchards, and vineyards
• Detection of potential frost damage to crops

## Quality Assurance Certificate

Together with this sensor we provide a quality assurance certificate in which the manufacturer ensures that the sensor has passed the internal quality procedures.

# Soil oxygen level sensor probe (Apogee SO-411 & SO-421)

Oxygen is the second major constituent of Earth's atmosphere and it is crucial for the development of life. There are sensors which measures oxygen in 2 states: dissolved in a solution and in a gaseous state. The Soil oxygen level sensor probe measures gaseous oxygen.
The Soil oxygen level sensor probe consists of a galvanic cell type sensor and offers a measure of the percentage of the total number of molecules of oxygen in the air. This sensor is specially designed for use in soil or porous media.
Figure: Soil oxygen level sensor probe (Apogee SO-411 or Apogee SO-421)
Figure: SO-411 sensor with the diffusion head AO-001, included by default

## Specifications

• Operating environment: -20 to 60 ºC; 60 to 114 kPa
• Operation humidity: 0 ~ 100% RH (non-condensing)
• Measurement range: 0 to 100% O2
• Measurement repeatability: less than 0.1% of mV output at 20.95% O2
• Non-linearity: less than 1%
• Long-term drift (non-stability): 1.0 mV per year
• Oxygen consumption rate: 2.2 µmol O2 per day at 20.95% O2 and 23 ºC
• Response time: 60 s for SO-411 (14 s for SO-421)
• Dimensions: 32 mm diameter, 68 mm length
• Mass: 175 g
• Cable length: 5 m
Due to provisioning challenges with the SO-411, Libelium also distributes the SO-421 since 2021. It is an equivalent sensor, so consider this section valid for both with the next differences:
• Response time: 14 s
• Long-term drift (non-stability): 0.8 mV per year
• Shorter life (~5 years instead of 10)

## Measurement process

The SO-411 and SO-421 sensors provide a digital signal using the SDI-12 protocol.
1
{
2
// 1. Declare an object for the sensor
3
Apogee_SO411 mySensor(XTR_SOCKET_A);
4
5
// 2. Turn ON the sensor
6
mySensor.ON();
7
8
// 3. Initialization delay, necessary for this sensor
9
delay(60000);
10
11
// 4. Read the sensor. Values stored in class variables
12
// Check complete code example for details
13
14
15
// 5. Turn off the sensor
16
mySensor.OFF();
17
}
Copied!
You can find a complete example code for reading this sensor probe in the following link: https://development.libelium.com/ag-xtr-03-so-411-sensor-reading/
And also there is a dedicated example for the SO-421 in the next link: https://development.libelium.com/ag-xtr-30-so-421-sensor-reading/

## Socket

Connect the SO-411 or the SO-421 sensor probes to Plug & Sense! Smart Agriculture Xtreme in any of the sockets shown in the image below.
Figure: Available sockets for the SO-411 and SO-421 sensor probes

## Installation

The SO-411 sensor is designed to be installed in soil or porous media in vertical position, with the opening pointing down and the cable pointing up.
This sensor can be used with the accessory model A0-001, designed to facilitate measurements in soil or porous media. It consists of a diffusion head that maintains an air pocket and provides protection to the teflon membrane where gas diffusion occurs.
It is highly recommended to use the SO-411 sensor probe together with the diffusion head to keep the sensor opening clear from soil and ensure accurate readings. That's why Libelium always includes the diffusion head along with the sensor probe.
There are possibilities that the SO-411 sensor is saturated by too much water, which will cause strange readings until the inner membrane of the sensor dries out. The amount of time it takes to dry out is dependent on the outside conditions (i.e humidity, temperature). Sometimes if the sensor gets dropped on a hard surface or something comparable, the sensor will also read off until it has re-stabilized itself.
Figure: SO-411 sensor installation with diffusion head accessory
You can find the complete sensor manual on the manufacturer\'s website.

## Application examples

• Measurement of O2 in laboratory experiments
• Monitoring gaseous O2 in indoor environments for climate control
• Monitoring of O2 levels in compost piles and mine tailings
• Monitoring redox potential in soils
• Determination of respiration rates through measurement of O2 consumption in sealed chambers
• Measurement of O2 gradients in soil/porous media

## Quality Assurance Certificate

Together with this sensor we provide a quality assurance certificate in which the manufacturer ensures that the sensor has passed the internal quality procedures.

# Shortwave radiation sensor probe (Apogee SP-510)

The Shortwave radiation sensor probe (Apogee SP-510) measures incoming global shortwave radiation from the Sun. Shortwave radiation is radiant energy with wavelengths in the visible (VIS), near-ultraviolet (UV), and near-infrared (NIR) spectra.
This sensor consists of a thermopile detector, acrylic diffuser, heater, and signal processing circuitry mounted in an anodized aluminum housing.
Figure: Shortwave radiation sensor probe (Apogee SP-510)

## Specifications

• Operating temperature: -50 to 80 ºC
• Operation humidity: 0 ~ 100% RH
• Sensitivity (variable from sensor to sensor, typical values listed): 0.057 mV per W m^-2
• Calibration factor (reciprocal of sensitivity): 17.5 W m^-2 per mV
• Calibration uncertainty: ± 5%
• Calibrated output range: 0 to 114 mV
• Measurement range: 0 to 2000 W m^-2 (net shortwave radiation)
• Measurement repeatability: less than 1%
• Long-term drift (non-stability): less than 2% per year
• Non-linearity: less than 1%
• Detector response time: 0.5 s
• Field of view: 180º
• Spectral range (wavelengths where response is 50% of maximum): 385 to 2105 nm
• Directional (cosine) response: less than 30 W m^-2 up to solar zenith angles of 80º
• Temperature response: less than 5% from -15 to 45 ºC
• Cable length: 5 m

## Measurement process

The SP-510 sensor provides an analog signal.
1
{
2
// 1. Declare an object for the sensor
3
Apogee_SP510 mySensor(XTR_SOCKET_B);
4
5
// 2. Turn ON the sensor
6
mySensor.ON();
7
8
// 3. Read the sensor. Values stored in class variables
9
// Check complete code example for details
10
11
12
// 4. Turn off the sensor
13
mySensor.OFF();
14
}
Copied!
You can find a complete example code for reading this sensor probe in the following link: https://development.libelium.com/ag-xtr-06-sp-510-sensor-reading/

## Socket

Connect the SP-510 sensor probe to Plug & Sense! Smart Agriculture Xtreme in any of the sockets shown in the image below.
Figure: Available sockets for the SP-510 sensor probe

## Installation

The SP-510 sensor includes a nylon mounting screw on the base in order to mount the sensor on a solid surface.
Figure: Pyranometer installation
The Solar sensors mounting accessory can also be used for the installation. This accessory is optional but highly recommended for the solar sensors. With this accessory you will get a secure fastening while keeping the sensor as level as possible, always pointing up.
The accessory is composed of 2 main parts: A - Mounting bracket: it will be fastened to a pipe or mast with its u-bolt B - Leveling plate: it holds the sensor and includes a bubble level
Figure: Solar sensors mounting accessory
Mounting the system is very easy, just follow these steps: 1 - Attach the solar sensor to the leveling plate, in its central hole. Use the black nylon screw (every sensor comes with one, find it on its bottom) and a screwdriver. 2 - Fasten the leveling plate to the mounting bracket with the 3 long gray screws. Do not insert them too firmly, the final adjustment is done later. 3 - Decide if you want to mount the whole structure to a vertical or horizontal pipe or mast (its outer diameter can go from 3.3 to 5.3 cm). Depending on horizontal or vertical configuration, you will use the bottom or the side of the mounting bracket. 4 - Place the black plastic piece in contact with the pipe. Then use the u-bolt to grab the mounting bracket to the pipe. On both ends of the u-bolt, insert first the washers, then the lock washers and finally the nuts. 5 - Place the structure in the desired position and tighten the nuts firmly with a wrench.
Figure: Final look of the whole structure
6 - You may take advantage of the holes on the mounting bracket and the pipe to secure the cable of the sensor, avoiding its rotation. You can do that with some cable ties. To minimize azimuth error, the sensor should be mounted with the cable pointing toward true north in the northern hemisphere or true south in the southern hemisphere. Azimuth error is typically less than 1%, but it is easy to minimize by proper cable orientation.7 - Once installed, use the long gray screws of the plate for fine adjustment of the level, making sure the bubble is inside the black circle. The wave spring will keep the leveling plate in place.
The sensor should be mounted so that obstructions (pipe/mast, sensors, enclosures, leaves, walls, etc) do not shade the sensor.
You can find the complete sensor manual on the manufacturer's website.

## Application examples

• Incoming shortwave radiation measurement in agricultural, ecological, and hydrological weather networks
• Optimization of photo-voltaic systems

## Certificate of calibration

Together with this sensor we provide a calibration certificate in which the manufacturer ensures that the sensor has passed a calibration procedure with traceability to an accredited laboratory.

# Solar radiation sensor probe for Smart Agriculture Xtreme (Apogee SQ-110)

Photosynthetically active radiation (PAR) is the radiation that drives photosynthesis and is typically defined as total radiation across a range from 400 to 700 nm. PAR is often expressed as photosynthetic photon flux density (PPFD): photon flux in units of micromoles per square meter per second (μmol·m^-2·s^-1).
Until July 2021, Libelium distributed this sensor, but it was discontinued by Apogee.
From July 2021, Libelium only offers the SQ-100x sensor for PAR metering, which replaces the SQ-110 and has a slightly better performace.
Figure: Solar radiation sensor probe for Smart Agriculture Xtreme (Apogee SQ-110)
Figure: Graph of the spectral response of the PAR sensor (Apogee SQ-110) compared to the photosynthetic response of a plant

## Specifications

• Operation temperature: -40 ~ 70 ºC
• Operation humidity: 0 ~ 100% RH
• Sensitivity: 0.2 mV / μmol·m^-2·s^-1
• Calibration factor (reciprocal of sensitivity): 5 μmol·m^-2·s^-1 / mV
• Non-linearity: < 1% (up to 4000 μmol·m^-2·s^-1 / mV)
• Non-stability (long-term drift): <2% per year
• Spectral range: 410 ~ 655 nm
• Repeatability: <0.5%
• Diameter: 2.4 cm
• Height: 2.8 cm
• Cable length: 5 m

## Measurement process

The SQ-110 sensor provides an analog signal.
1
{
2
// 1. Declare an object for the sensor
3
Apogee_SQ110 mySensor(XTR_SOCKET_B);
4
5
// 2. Turn ON the sensor
6
mySensor.ON();
7
8
// 3. Read the sensor. Values stored in class variables
9
// Check complete code example for details
10
11
12
// 4. Turn off the sensor
13
mySensor.OFF();
14
}
Copied!
You can find a complete example code for reading this sensor probe in the following link: https://development.libelium.com/ag-xtr-05-sq-110-sensor-reading/

## Socket

Connect the SQ-110 sensor probe to Plug & Sense! Smart Agriculture Xtreme in any of the sockets shown in the image below.
This sensor has a specific wiring for the Plug & Sense! Smart Agriculture Xtreme model, so it is not compatible with other Plug & Sense! models and vice versa. Refer to our Sales department for more information.
Figure: Available sockets for the SQ-110 sensor probe

## Installation

The SQ-110 sensor includes a nylon mounting screw on the base in order to mount the sensor on a solid surface.
Figure: SQ-110 sensor installation
The Solar sensors mounting accessory can also be used for the installation. This accessory is optional but highly recommended for the solar sensors. With this accessory you will get a secure fastening while keeping the sensor as level as possible, always pointing up.
The accessory is composed of 2 main parts: A - Mounting bracket: it will be fastened to a pipe or mast with its u-bolt B - Leveling plate: it holds the sensor and includes a bubble level
Figure: Solar sensors mounting accessory
Mounting the system is very easy, just follow these steps: 1 - Attach the solar sensor to the leveling plate, in its central hole. Use the black nylon screw (every sensor comes with one, find it on its bottom) and a screwdriver. 2 - Fasten the leveling plate to the mounting bracket with the 3 long gray screws. Do not insert them too firmly, the final adjustment is done later. 3 - Decide if you want to mount the whole structure to a vertical or horizontal pipe or mast (its outer diameter can go from 3.3 to 5.3 cm). Depending on horizontal or vertical configuration, you will use the bottom or the side of the mounting bracket. 4 - Place the black plastic piece in contact with the pipe. Then use the u-bolt to grab the mounting bracket to the pipe. On both ends of the u-bolt, insert first the washers, then the lock washers and finally the nuts. 5 - Place the structure in the desired position and tighten the nuts firmly with a wrench.
Figure: Final look of the whole structure
6 - You may take advantage of the holes on the mounting bracket and the pipe to secure the cable of the sensor, avoiding its rotation. You can do that with some cable ties. To minimize azimuth error, the sensor should be mounted with the cable pointing toward true north in the northern hemisphere or true south in the southern hemisphere. Azimuth error is typically less than 1%, but it is easy to minimize by proper cable orientation. 7 - Once installed, use the long gray screws of the plate for fine adjustment of the level, making sure the bubble is inside the black circle. The wave spring will keep the leveling plate in place.
The sensor should be mounted so that obstructions (pipe/mast, sensors, enclosures, leaves, walls, etc) do not shade the sensor.
You can find the complete sensor manual on the manufacturer's website.

## Application examples

Photosynthetic photon flux density (PPFD) measures in:
• Plant canopies in outdoor environments
• Greenhouses and growth chambers
• Evapotranspiration analysis
• Aquatic environments, including salt water aquariums where corals are grown

## Certificate of calibration

Together with this sensor we provide a calibration certificate in which the manufacturer ensures that the sensor has passed a calibration procedure with traceability to an accredited laboratory.

# Solar radiation sensor probe for Smart Agriculture Xtreme (Apogee SQ-100x)

Photosynthetically active radiation (PAR) is the radiation that drives photosynthesis and is typically defined as total radiation across a range from 400 to 700 nm. PAR is often expressed as photosynthetic photon flux density (PPFD): photon flux in units of micromoles per square meter per second (μmol·m^-2·s^-1).
Figure: Solar radiation sensor probe for Smart Agriculture Xtreme (Apogee SQ-100x)

## Specifications

• Operation temperature: -40 ~ 60 ºC
• Operation humidity: 0 ~ 100% RH
• Sensitivity: 0.1 mV / μmol·m^-2·s^-1
• Calibration factor (reciprocal of sensitivity): 10 μmol·m^-2·s^-1 / mV
• Non-linearity: < 1% (up to 4000 μmol·m^-2·s^-1 / mV)
• Non-stability (long-term drift): <2% per year
• Spectral range: 370 ~ 650 nm
• Repeatability: <0.5%
• Diameter: 2.4 cm
• Height: 3.3 cm
• Cable length: 5 m
Figure: Graph of the spectral response of the PAR sensor (Apogee SQ-100x) compared to the photosynthetic response of a plant

## Measurement process

The SQ-100x sensor provides an analog signal.
1
{
2
// 1. Declare an object for the sensor
3
Apogee_SQ100x mySensor(XTR_SOCKET_B);
4
5
// 2. Turn ON the sensor
6
mySensor.ON();
7
8
// 3. Read the sensor. Values stored in class variables
9
// Check complete code example for details
10
11
12
// 4. Turn off the sensor
13
mySensor.OFF();
14
}
Copied!
You can find a complete example code for reading this sensor probe in the following link: https://development.libelium.com/ag-xtr-05b-sq-100-x-sensor-reading/

## Socket

Connect the SQ-100x sensor probe to Plug & Sense! Smart Agriculture Xtreme in any of the sockets shown in the image below.
This sensor has a specific wiring for the Plug & Sense! Smart Agriculture Xtreme model, so it is not compatible with other Plug & Sense! models and vice versa. Refer to our Sales department for more information.
Figure: Available sockets for the SQ-100x sensor probe

## Installation

The SQ-100x sensor includes a nylon mounting screw on the base in order to mount the sensor on a solid surface.
Figure: SQ-100x sensor installation
The Solar sensors mounting accessory can also be used for the installation. This accessory is optional but highly recommended for the solar sensors. With this accessory you will get a secure fastening while keeping the sensor as level as possible, always pointing up.
The accessory is composed of 2 main parts: A - Mounting bracket: it will be fastened to a pipe or mast with its u-bolt B - Leveling plate: it holds the sensor and includes a bubble level
Figure: Solar sensors mounting accessory
Mounting the system is very easy, just follow these steps: 1 - Attach the solar sensor to the leveling plate, in its central hole. Use the black nylon screw (every sensor comes with one, find it on its bottom) and a screwdriver. 2 - Fasten the leveling plate to the mounting bracket with the 3 long gray screws. Do not insert them too firmly, the final adjustment is done later. 3 - Decide if you want to mount the whole structure to a vertical or horizontal pipe or mast (its outer diameter can go from 3.3 to 5.3 cm). Depending on horizontal or vertical configuration, you will use the bottom or the side of the mounting bracket. 4 - Place the black plastic piece in contact with the pipe. Then use the u-bolt to grab the mounting bracket to the pipe. On both ends of the u-bolt, insert first the washers, then the lock washers and finally the nuts. 5 - Place the structure in the desired position and tighten the nuts firmly with a wrench.
Figure: Final look of the whole structure
6 - You may take advantage of the holes on the mounting bracket and the pipe to secure the cable of the sensor, avoiding its rotation. You can do that with some cable ties. To minimize azimuth error, the sensor should be mounted with the cable pointing toward true north in the northern hemisphere or true south in the southern hemisphere. Azimuth error is typically less than 1%, but it is easy to minimize by proper cable orientation. 7 - Once installed, use the long gray screws of the plate for fine adjustment of the level, making sure the bubble is inside the black circle. The wave spring will keep the leveling plate in place.
The sensor should be mounted so that obstructions (pipe/mast, sensors, enclosures, leaves, walls, etc) do not shade the sensor.
You can find the complete sensor manual on the manufacturer's website.

## Application examples

Photosynthetic photon flux density (PPFD) measures in:
• Plant canopies in outdoor environments
• Greenhouses and growth chambers
• Evapotranspiration analysis
• Aquatic environments, including salt water aquariums where corals are grown

## Certificate of calibration

Together with this sensor we provide a calibration certificate in which the manufacturer ensures that the sensor has passed a calibration procedure with traceability to an accredited laboratory.

# Ultraviolet radiation sensor probe for Smart Agriculture Xtreme (Apogee SU-100)

Ultraviolet (UV) radiation is typically defined as total radiation across a range from 100 to 400 nm and is subdivided into 3 wavelength ranges: UV-A (315 to 400 nm), UV-B (280 to 315 nm) and UV-C (100 to 280 nm). Much of the UV-B and all of the UV-C wavelengths from the sun are absorbed by the Earth's atmosphere.
The Ultraviolet radiation sensor probe for Smart Agriculture Xtreme (Apogee SU-100) detects UV radiation from 250 to 400 nm and is calibrated in photon flux units of micromoles per square meter per second (μmol·m^-2·s^-1).
Note: Apogee has recently updated its ultraviolet sensors. The new SU-202 sensor is the substitute for the SU-100, which is no longer available for purchase.
Figure: Ultraviolet radiation sensor probe for Smart Agriculture Xtreme (Apogee SU-100)
Figure: Graph of the spectral response of the SU-100 sensor probe compared to the photosynthetic response of a plant

## Specifications

• Operation temperature: -40 to 70 ºC
• Operation humidity: 0 to 100%
• Sensitivity: 0.2 mV / μmol·m^-2·s^-1
• Calibration factor (reciprocal of sensitivity): 5.0 μmol·m^-2·s^-1 / mV
• Non-stability (long-term drift): <3% per year
• Non-linearity: <1% (up to 300 μmol·m^-2·s^-1)
• Spectral range: 250 ~ 400 nm
• Repeatability: <1%
• Diameter: 2.4 cm
• Height: 2.8 cm
• Cable length: 5 m

## Measurement process

The SU-100 sensor provides an analog signal.
1
{
2
// 1. Declare an object for the sensor
3
Apogee_SU100 mySensor(XTR_SOCKET_B);
4
5
// 2. Turn ON the sensor
6
mySensor.ON();
7
8
// 3. Read the sensor. Values stored in class variables
9
// Check complete code example for details
10
11
12
// 4. Turn off the sensor
13
mySensor.OFF();
14
}
Copied!
You can find a complete example code for reading this sensor probe in the following link: https://development.libelium.com/ag-xtr-04-su-100-sensor-reading/

## Socket

Connect the SU-100 sensor probe to Plug & Sense! Smart Agriculture Xtreme in any of the sockets shown in the image below.
This sensor has a specific wiring for the Plug & Sense! Smart Agriculture Xtreme model, so it is not compatible with other Plug & Sense! models and vice versa. Refer to our Sales department for more information.
Figure: Available sockets for the SU-100 sensor probe

## Installation

The SU-100 sensor includes a nylon mounting screw on the base in order to mount the sensor on a solid surface.
Figure: SU-100 sensor probe installation
The Solar sensors mounting accessory can also be used for the installation. This accessory is optional but highly recommended for the solar sensors. With this accessory you will get a secure fastening while keeping the sensor as level as possible, always pointing up.
The accessory is composed of 2 main parts: A - Mounting bracket: it will be fastened to a pipe or mast with its u-bolt. B - Leveling plate: it holds the sensor and includes a bubble level.
Figure: Solar sensors mounting accessory
Mounting the system is very easy, just follow these steps: 1 - Attach the solar sensor to the leveling plate, in its central hole. Use the black nylon screw (every sensor comes with one, find it on its bottom) and a screwdriver. 2 - Fasten the leveling plate to the mounting bracket with the 3 long gray screws. Do not insert them too firmly, the final adjustment is done later. 3 - Decide if you want to mount the whole structure to a vertical or horizontal pipe or mast (its outer diameter can go from 3.3 to 5.3 cm). Depending on horizontal or vertical configuration, you will use the bottom or the side of the mounting bracket. 4 - Place the black plastic piece in contact with the pipe. Then use the u-bolt to grab the mounting bracket to the pipe. On both ends of the u-bolt, insert first the washers, then the lock washers and finally the nuts. 5 - Place the structure in the desired position and tighten the nuts firmly with a wrench.
Figure: Final look of the whole structure
6 - You may take advantage of the holes on the mounting bracket and the pipe to secure the cable of the sensor, avoiding its rotation. You can do that with some cable ties. To minimize azimuth error, the sensor should be mounted with the cable pointing toward true north in the northern hemisphere or true south in the southern hemisphere. Azimuth error is typically less than 1%, but it is easy to minimize by proper cable orientation. 7 - Once installed, use the long gray screws of the plate for fine adjustment of the level, making sure the bubble is inside the black circle. The wave spring will keep the leveling plate in place.
The sensor should be mounted so that obstructions (pipe/mast, sensors, enclosures, leaves, walls, etc) do not shade the sensor.
You can find the complete sensor manual on the manufacturer's website.

## Application examples

• Outdoor environments
• Laboratory use with artificial light sources (e.g. germicidal lamps)
• Monitoring the filter ability and stability of different materials

## Certificate of calibration

Together with this sensor we provide a calibration certificate in which the manufacturer ensures that the sensor has passed a calibration procedure with traceability to an accredited laboratory.

# Ultraviolet radiation sensor probe for Smart Agriculture Xtreme (Apogee SU-202)

Apogee has recently updated its ultraviolet sensors. The new SU-202 sensor is the substitute for the SU-100, which is discontinued. It is available for the Smart Agriculture Xtreme line.
The Ultraviolet radiation sensor probe for Smart Agriculture Xtreme (Apogee SU-202) detects UV radiation from 300 to 400 nm and is calibrated in photon flux units of micromoles per square meter per second (μmol·m-2s-1).
Figure: Ultraviolet radiation sensor probe for Smart Agriculture Xtreme (Apogee SU-202)
Figure: Graph of the spectral response of the SU-202 compared to the photosynthetic response of a plant

## Specifications

• Operation temperature: -30 to 85 ºC
• Operation humidity: 0 to 100%
• Temperature response: -0.1% per ºC
• Sensitivity: 8.33 mV / μmol·m^-2·s^-1
• Calibration factor (reciprocal of sensitivity): 0.12 μmol·m^-2·s^-1 / mV
• Calibration uncertainty: ±10%
• Spectral range: 300 ~ 400 nm (wavelengths where response is greater than 10 % of maximum)
• Measurement range: 0 to 100 Wm−2
• Repeatability: <0.5%
• Long-term drift: Less than 2% per year
• Non-linearity: Less than 1%
• Field overview: 180º
• Directional (cosine) response: ±2% at 45º; ± 5 % at 75º zenith angle
• Dimensions: 30.5 mm diameter, 37 mm height

## Measurement process

The SU-202 sensor provides an analog signal.
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{
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// 1. Declare an object for the sensor
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Apogee_SU202 mySensor(XTR_SOCKET_B);
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// 2. Turn ON the sensor
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mySensor.ON();
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// 3. Read the sensor. Values stored in class variables
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// Check complete code example for details
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// 4. Turn off the sensor
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mySensor.OFF();
14
}
Copied!
You can find a complete example code for reading this sensor probe in the following link: https://development.libelium.com/ag-xtr-29-su-202-sensor-reading/

## Socket

Connect the SU-202 sensor probe to Plug & Sense! Smart Agriculture Xtreme in any of the sockets shown in the image below.
This sensor specific wiring for the Plug & Sense! Smart Agriculture Xtreme model, so it is not compatible with other Plug & Sense! models and vice versa. Refer to our Sales department for more information.
Figure: Available sockets for the SU-202 sensor probe

## Installation

The SU-202 sensor includes a nylon mounting screw on the base in order to mount the sensor on a solid surface.
Figure: SU-202 sensor probe installation
The Solar sensors mounting accessory can also be used for the installation. This accessory is optional but highly recommended for the solar sensors. With this accessory you will get a secure fastening while keeping the sensor as level as possible, always pointing up.
The accessory is composed of 2 main parts: A - Mounting bracket: it will be fastened to a pipe or mast with its u-bolt. B - Leveling plate: it holds the sensor and includes a bubble level.
Figure: Solar sensors mounting accessory
Mounting the system is very easy, just follow these steps: 1 - Attach the solar sensor to the leveling plate, in its central hole. Use the black nylon screw (every sensor comes with one, find it on its bottom) and a screwdriver. 2 - Fasten the leveling plate to the mounting bracket with the 3 long gray screws. Do not insert them too firmly, the final adjustment is done later. 3 - Decide if you want to mount the whole structure to a vertical or horizontal pipe or mast (its outer diameter can go from 3.3 to 5.3 cm). Depending on the horizontal or vertical configuration, you will use the bottom or the side of the mounting bracket. 4 - Place the black plastic piece in contact with the pipe. Then use the u-bolt to grab the mounting bracket to the pipe. On both ends of the u-bolt, insert first the washers, then the lock washers and finally the nuts. 5 - Place the structure in the desired position and tighten the nuts firmly with a wrench.
Figure: Final look of the whole structure
6 - You may take advantage of the holes on the mounting bracket and the pipe to secure the cable of the sensor, avoiding its rotation. You can do that with some cable ties. To minimize azimuth error, the sensor should be mounted with the cable pointing toward true north in the northern hemisphere or true south in the southern hemisphere. Azimuth error is typically less than 1%, but it is easy to minimize by proper cable orientation. 7 - Once installed, use the long gray screws of the plate for fine adjustment of the level, making sure the bubble is inside the black circle. The wave spring will keep the leveling plate in place.
The sensor should be mounted so that obstructions (pipe/mast, sensors, enclosures, leaves, walls, etc) do not shade the sensor.
You can find the complete sensor manual on the manufacturer's website.

## Application examples

• Outdoor environments
• Laboratory use with artificial light sources (e.g. germicidal lamps)
• Monitoring the filter ability and stability of different materials

## Certificate of calibration

Together with this sensor, we provide a calibration certificate in which the manufacturer ensures that the sensor has passed a calibration procedure with traceability to an accredited laboratory.

# Temperature, humidity and pressure sensor probe (Bosch BME280)

The Bosch BME280 includes a humidity sensor that features an extremely fast response time which supports performance requirements for emerging applications such as context awareness, and high accuracy over a wide temperature range. The pressure sensor is an absolute barometric pressure sensor with features exceptionally high accuracy and resolution at very low noise. The integrated temperature sensor has been optimized for very low noise and high resolution. It is primarily used for temperature compensation of the pressure and humidity sensors, and can also be used for estimating ambient temperature.
Figure: Temperature, humidity and pressure sensor (Bosch BME280)

## Specifications

### Temperature sensor

• Operational range: -40 ~ +85 ºC
• Full accuracy range: 0 ~ +65 ºC
• Accuracy: ±1 ºC (range 0 ºC ~ +65 ºC)
• Response time: 1.65 seconds (63% response from +30 to +125 °C)

### Humidity sensor

• Measurement range: 0 ~ 100% of relative humidity (for temperatures < 0 °C and > 60 °C see figure below) Accuracy: < ±3% RH (at 25 ºC, range 20 ~ 80%)
• Hysteresis: ±1% RH
• Operating temperature: -40 ~ +85 ºC
• Response time (63% of step 90% to 0% or 0% to 90%): 1 second
Figure: Humidity sensor operating range

### Pressure sensor

• Measurement range: 30 ~ 110 kPa
• Operational temperature range: -40 ~ +85 ºC
• Full accuracy temperature range: 0 ~ +65 ºC
• Absolute accuracy: ±0.1 kPa (0 ~ 65 ºC)

## Measurement process

The Temperature, humidity and pressure sensor provides a digital signal using the I2C protocol.
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{
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// 1. Declare an object for the sensor
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bme mySensor(XTR_SOCKET_A);
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// 2. Turn ON the sensor
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mySensor.ON();
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// 3. Read the sensor. Store parameters in local variables
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float temperature = mySensor.getTemperature();
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float humidity = mySensor.getHumidity();
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float pressure = mySensor.getPressure();
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// 4. Turn off the sensor
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mySensor.OFF();
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}
Copied!
You can find a complete example code for reading this sensor probe in the following link: https://development.libelium.com/ag-xtr-16-bme280-sensor-reading/

## Socket

Connect the Temperature, humidity and pressure sensor probe (Bosch BME280) to Plug & Sense! Smart Agriculture Xtreme in any of the sockets shown in the image below.
Figure: Available sockets for the Temperature, humidity and pressure sensor probe (Bosch BME280)

## Application examples

• Weather observation and forecast
• Evapotranspiration analysis
• Control heating, ventilation or air conditioning in greenhouses
• Warning regarding dryness or high temperatures

# Conductivity, water content and soil temperature GS3 sensor probe (Decagon GS3)

This sensor probe was discontinued by Libelium in July 2020 since it was discontinued by its manufacturer. From that moment, our customers can choose the equivalent TEROS 11 and TEROS 12 sensor probes.
The Conductivity, water content and soil temperature sensor probe (Decagon GS3) can measure many types of growing media, specially in greenhouse applications where the probe can be inserted easily into different types of soilless substrates. The GS3 sensor determines volumetric water content (VWC) by measuring the dielectric constant (εa) of the medium using capacitance / frequency-domain technology, the temperature using a thermistor, and electrical conductivity using a stainless steel electrode array.
Figure: Conductivity, water content and soil temperature GS3 sensor probe (Decagon GS3)

## Specifications

### General specifications

• Operating temperature: -40 to 60 ºC
• Dielectric measurement frequency: 70 MHz
• Measurement time: 150 ms
• Dimensions: 9.3 x 2.4 x 6.5 cm
• Prong length: 5.5 cm
• Cable length: 5 m

### Volumetric water content

• Accuracy: εa: ±1 εa (unitless) from 1 to 40 (soil range), ±15% from 40 to 80
• Resolution:
• 0.1 εa (unitless) from 1 to 20
• < 0.75 εa (unitless) from 20 to 80
• 0.002 m³/m³ (0.2% VWC) from 0 to 40% VWC
• 0.001 m³/m³ (0.1% VWC) > 40% VWC
• Range: Apparent dielectric permittivity (εa): 1 (air) to 80 (water)

### Bulk electrical conductivity

• Accuracy: ± 5% from 0 to 5 dS/m, ±10% from 5 to 23 dS/m
• Resolution: 0.001 dS/m from 0 to 23 dS/m
• Range: 0 to 25 dS/m (bulk)

### Temperature

• Accuracy: ±1 ºC
• Resolution: 0.1 ºC
• Range: -40 to 60 ºC

## Measurement process

The GS3 sensor provides a digital signal using the SDI-12 protocol.
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{
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// 1. Declare an object for the sensor
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Decagon_GS3 mySensor(XTR_SOCKET_A);
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// 2. Turn ON the sensor
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mySensor.ON();
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// 3. Read the sensor. Values stored in class variables
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// Check complete code example for details
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// 4. Turn off the sensor
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mySensor.OFF();
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}
Copied!
Volumetric water content (VWC) calculation
The GS3 sensor provides the dielectric permittivity (ε~) of the surrounding medium. The dielectric permittivity value must be converted in the code to a particular substrate by a calibration equation specific to the media you are working in.
The calibration equation for several potting soils, perlite, and peat moss at salinities ranging from 0 to > 4 dS/m is:
$VWC(m³/m³) =0.118*sqrt(εa) - 0.117$
The calibration equation for mineral soils ranging from 0 to > 5 dS/m is:
$VWC(m³/m³) = 5.89*10⁻⁶*εa³-7.62*10⁻⁴*εa²+3.67*10⁻²*εa-7.53*10⁻²$
You can find a complete example code for reading this sensor probe and for calculating VWC for mineral soil in the following link: https://development.libelium.com/ag-xtr-07-gs3-sensor-reading/

## Socket

Connect the GS3 sensor probe to Plug & Sense! Smart Agriculture Xtreme in any of the sockets shown in the image below.
Figure: Available sockets for the GS3 sensor probe

## Installation

The GS3 sensor can be inserted into soilless substrates in different ways. However, the orientation of the sensor does affect the sensor readings. Please keep in mind that the sensor only measures the VWC in its sphere of influence.
Sensors can either be inserted into the top of the plant pot or into the side of the root ball. Insertion into the side of the root ball may be the best option, as it will give the best indication of the water available to the plant.
Figure: GS3 sensor installation
You can find the complete sensor manual on the manufacturer's website.

## Application examples

• Maintain good soil contact and compensate for air gaps in the substrate of potting soil or soilless medias
• Greenhouse substrate monitoring
• Irrigation management
• Salt management
• Fertilizer movement
• Modeling processes that are affected by temperature

## Quality Assurance Certificate

Together with this sensor we provide a quality assurance certificate in which the manufacturer ensures that the sensor has passed the internal quality procedures.

# Volumetric water content and soil temperature TEROS 11 sensor probe (Meter TEROS 11)

The Volumetric water content and soil temperature sensor probe (Meter TEROS 11) can measure many types of growing media, especially in greenhouse applications where the probe can be inserted easily into different types of soilless substrates. The TEROS 11 sensor determines volumetric water content (VWC) using capacitance / frequency-domain technology and the temperature using a thermistor.
Figure: Volumetric water content and soil temperature TEROS 11 sensor probe (Meter TEROS 11)

## Specifications

### General specifications

• Operating temperature: -40 to 60 ºC
• Dielectric measurement frequency: 70 MHz
• Measurement time: 150 ms (maximum)
• Dimensions: 9.4 x 2.4 x 7.5 cm
• Needle length: 5.5 cm
• Cable length: 5 m

### Volumetric water content

• Accuracy: ±0.03 m³/m³ typical in mineral soils that have solution electrical conductivity < 8 dS/m
• Resolution: 0.001 m³/m³
• Range: Mineral soil calibration: 0.00-0.70 m³/m³; Soilless media calibration: 0.0-1.0 m³/m³
The VWC range is dependent on the media the sensor is calibrated to. A custom calibration will accommodate the necessary ranges for most substrates.

### Temperature

• Accuracy: ±1 ºC from -40 to 0 ºC, ±0.5 ºC from 0 to 60 ºC
• Resolution: 0.1 ºC
• Range: -40 to 60 ºC

## Measurement process

The TEROS 11 sensor provides a digital signal using the SDI-12 protocol.
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{
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// 1. Declare an object for the sensor
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Meter_TEROS11 mySensor(XTR_SOCKET_A);
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// 2. Turn ON the sensor
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mySensor.ON();
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// 3. Read the sensor. Values stored in class variables
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// Check complete code example for details
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11
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// 4. Turn off the sensor
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mySensor.OFF();
14
}
Copied!
Volumetric water content (VWC) calculation
The TEROS 11 sensor provides a raw output to calculate the VWC and the dielectric permittivity (εa) of the surrounding medium. The VWC value must be converted in the code to a particular substrate by a calibration equation specific to the media you are working in.
The calibration equation for several potting soils, perlite, and peat moss at salinities is:
$VWC(m³/m³) = 6.771*10⁻¹⁰*RAW³-5.105*10⁻⁶*RAW²+1.302*10⁻²*RAW-10.848$
The calibration equation for mineral soils ranging from 0 to to 8 dS/m is:
$VWC(m³/m³) = 5.89*10⁻⁶*εa³-7.62*10⁻⁴*εa²+3.67*10⁻²*εa-7.53*10⁻²$

### Dielectric Permittivity calculation (ε)

Dielectric Permittivity is calculated from the raw output following the next equation: