GREENHOUSEg u i d e l i n e s

INNOVATIVE INDUSTRIAL IOT SOLUTIONS FOR BUSINESS, MAKING ENVIRONMENTAL MONITORING EASY!

Modern greenhouses are filled with high-tech tools and systems for monitoring and controlling the growing environment. They typically include:

U automated window operations

U computerized climate-control ventilation fans and heaters

U CO2 level monitoring

U automated irrigation and nutrient delivery systems

The Aranet solution uses wireless sensors that can transmit data readings every minute to the centrally located base station (gateway). This provides the ultimate flexibility for moving the sensors around while finding the most suitable placement - independent of any wiring!

The Aranet system helps to fine-tune your grow operation to maximize yield by monitoring:

U Air temperature and humidity

U PAR light level

U CO2 level

U Water level in the substrate

U Salinity (EC) level in the substrate

U Temperature of the substrate

U pH level of the substrate (water, soil)

U Weight of the substrate and plants

U Micro-variation of stem diameter

The following discussion provides suggestions and tips for positioning Aranet sensors. In every modern greenhouse there lives a unique breathing environment. Don’t be shy about using the flexibility of the Aranet wireless sensors and continue to experiment with sensor placements until you get it just right for your greenhouse configuration.

The sweet spot for the Base station placement is in the middle of all the sensors that are sending data to it. Remember to install it as high as possible, well above the maximum height of the plants.

If the base station can’t be placed in the middle of the greenhouse (section), locate it in a convenient place and check to make sure you are getting a good signal from the furthest sensor.

Observations indicate that distance between base station and sensors can be up to 100 – 150 meters in a typical greenhouse (steel construction, glass walls with few gates/doors).

Estimate the maximum height of your plants when they reach harvest time. We suggest placing the base station and sensors about a foot above the maximum expected plant heights.

The large water content in the plants and fruits is the main contributor to weakening of the radio signal if the sensors and base station are placed too low.

This is a good example of the temperature and RH sensor with convection shield being placed well above the plants for good signal transmission.

In this example the weight load device is placed correctly but the transmitter (white body) is positioned below the max height of the plants.

Example of good installation case of weight sensor. Both, the weight load cell and transmitter (white body) are positioned above the max height if plants.

Guidelines for Greenhouse Growers

General guideline for sensor placement

Position of the base station

Optimal place for Base Station

Alternative place for Base Station

Optimal place for Base Station

Alternative place for Base Station

Air T/Humidity

Zone 1

Air T/Humidity

Zone 5

Air T/Humidity

Zone 3

Air T/Humidity

Zone 7

Air T/Humidity

Zone 2

Air T/Humidity

Zone 6

Air T/Humidity

Zone 4

Air T/Humidity

Zone 8

Base Station

Section 1

T/H, PAR, CO2, Soil... sensors T/H, PAR, CO2, Soil... sensors

Section 2We often get this question from our customers. The answer is, it depends.

If you have your greenhouse divided into sections where in each of section you can open/close windows, start ventilation fans, regulate temperature, adjust the CO2 gas level, adjust the content and amount of the irrigation solution, etc.… then typically, one type of sensor from our horticulture solution per section is sufficient (temperature/humidity, CO2, soil moisture, weight sensors, PAR sensor).

Placement of the Soil Moisture/EC/Temperature sensor depends on the type of substrate you are using. For some, the best results will be inserting the probe (needles of the sensor) from the top, others work best from side. For optimal results, experiment with the probe position until you achieve acceptable readings. Once you find your best placement adjustment of the calibration curve should be performed (see the Aranet SensorHUB software for details).

The PAR (photosynthetically active radiation) sensor measures the amount of light radiation (within 400-700 nm) that your plants are exposed to. The total amount of light radiation consists of sun radiation plus any artificial source of light from specialized light bulbs or LED lamps.

It’s important to place the PAR sensor in a position with equal amounts of light radiated from different LED lamps (try to achieve equal influence from the closest LED sources).

If possible, position the PAR sensor about 1 meter below the LED lamps and close to the height of your plant for the current growth stage.

Our experience with 10 cm thick rockwool substrate shows the best results are achieved placing the sensor probe from into the side of substrate and closer to bottom of it (shown in the picture below).

Regardless of the number of sections, sometimes you need temperature and RH control down to individual zones. You can add up to 100 sensors per base station – add as many as you need for micro-control of your greenhouse.

How many sensors do I need per section?

Soil Moisture/EC and Temp sensor

PAR sensor

height of plant for current growth stage

PAR Sensor

~ 1 meter

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For more detailed information about Aranet products visit www.aranet.com, contact your Aranet representative or write to info@aranet.com. Product specifications are subject to change without prior notice. Copyright © 2019 SAF Tehnika, JSC. All rights reserved.