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6 Things to Consider When Choosing Greenhouse Sensors

Greenhouse Sensors

Sensors are key components of greenhouse monitoring systems. Each sensor continually measures a specific condition like temperature or humidity in a specific location and reports those measurements to the system. Each sensor is connected to one of the base unit’s input terminal strips. Because each condition requires its own input, you have to match your needs with the number of inputs available.

We recommend you use greenhouse sensors that are rated for outdoor use to monitor temperature, humidity or CO2. Sensors designed for residential use won’t last long in a greenhouse because of the high humidity.

Where should I place sensors?

Greenhouse sensors can be placed in the soil, mounted to posts or walls, or placed on equipment, depending on their type and what condition you want to monitor. Hardwired sensors can be placed up to 2,000’ away from the main monitoring device. Wireless sensors can be placed up to 300' away from their gateway device or farther if they're used in a mesh network configuration.

What types of sensors are useful in greenhouses?

Temperature and humidity sensors are used most often. Greenhouse sensors are also commonly used for the following:

  • Moisture detection - Sensors placed in the soil will measure moisture content.
  • Equipment monitoring – Sensors placed on misting and irrigation systems will monitor the performance of pumps and pressure lines. Place sensors on vented roofs, side vents and fans so that you get an alert if any of them stop running or operate outside of preset parameters.
  • Access control - Sensors placed on entrance doors, windows, supply rooms and equipment sheds will alert you to any unauthorized entry into your facility during off-hours when no staff is on duty.
  • Power supply monitoring – Electricity powers critical equipment like lighting, water wells, heater fans, louvers, sprinklers and humidifiers. Sensors will immediately detect electric outages.
  • CO2 level – Sensors mounted in your greenhouse will detect when CO2 goes above or below your critical threshold.
  • Air circulation monitoring – Sensors placed on automatic ventilation systems like vented roofs, side vents and forced fans will alert you if these systems stop running or start operating outside preset parameters.
  • Water pH levels – Sensors can prevent nutrient deficiencies that occur in over- or under-acidic water by sampling the water’s pH as it runs through the pipe. Sensors are tapped into existing plumbing.

Should I use hardwired or wireless sensors?

A hardwired monitoring system connects the sensors to the base device with wires. Generally, trenching long distances for wires is time-consuming and costly but results in a very reliable system.

If hardwiring greenhouse sensors is logistically difficult or cost prohibitive at your location, you can select a system that uses wireless sensors with built-in radio transmitters to communicate with the base unit. Some monitoring systems can accommodate a combination of hardwired and wireless sensors.

How can I access my sensor readings?

Many systems provide a real-time status of all monitored conditions. If the monitoring system is cloud-based, it stores all of the data in the cloud. This means that you can always access sensor data from any internet connected device, such as a tablet or phone.

For example, Sensaphone Sentinel systems can be accessed from or the Sensaphone mobile app. Other monitoring systems use a phone line that users can call for status updates. Sensor access options include:

  • Calling to check status
  • Viewing a web page
  • Mobile app

Do I need to log data from my sensors?

Data history helps identify patterns and trends in greenhouse environmental conditions so you can address problems early. However, manually monitoring and recording data takes a significant amount of personnel time and detracts from other important workplace demands.

Many monitoring systems provide data logging functionality. They automatically save sensor readings, recording tens of thousands of data points, dates and times.

For example, if you’re interested in analyzing the temperature in your greenhouse over the course of time, you can set logging intervals. Reviewing data over a period of time can provide insight into why plants are growing at a reduced rate.

Cloud-based systems let you remotely view, graph, print and export this information. You can view the status of multiple locations, access trending reports, check specific equipment status and review alarm history without having to install any software.

How do I install and program greenhouse sensors?

It’s very easy to install sensors. Most sensors use two wires that are inserted into the terminal block of the monitoring system’s base unit and tightened with a screwdriver. If needed, you can extend the length of the sensor wire so they can be placed farther than 1,000 feet.

Be sure to consult the owner's manual guide to make sure you’re using the appropriate gauge wire based on the distance and sensor type. It's also easy to program sensors using the device’s keypad or through the website or app.

For additional greenhouse sensor considerations, visit New Greenhouse Sensors Open Up New Monitoring Possibilities.

We are happy to help you select or install hardwired or wireless sensors in your greenhouse. Call Sensaphone today at 877-959-0478!



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