Step-by-Step Tutorial: Build a Freezer Alarm System

The Importance of Freezer Alarm Systems

Temperature control is a major issue across the world in many different industries.

Up to 35% of vaccines are compromised due to poor temperature control every year—the largest contributor to vaccine loss.

Roughly one-third of all food produced around the world, valued at about $1 trillion, is wasted, in part because of poor temperature control during transport and storage.

In the United States, the USDA estimates that food-borne illnesses cost more than $15.6 billion every year, with poor temperature control of food being a leading cause of these illnesses.

Of course, all of this waste and expense is bad for the world. It’s also a particularly pressing issue for any business that relies on keeping its products or materials at a particular temperature.

Freezers in a supermarket

For the many businesses that use refrigerators and freezers, especially in the food & beverage industry, reliable freezer alarm systems can literally be a life or death issue.

How Freezer Alarm Systems are Used

With a freezer alarm system, food producers, restaurants, medical facilities, and other organizations can understand how their refrigerators and freezers are operating and thus know whether what’s stored inside is being handled safely.

The data can be used to: 

Prevent product loss: Automatic logging of temperature data can be used to notify staff of any imminent problems. By regularly reviewing temperature readings or, even better, setting up automated alerts, organizations can see when temperatures are starting to rise or fall outside of their desired ranges.

This provides an opportunity to fix the malfunctioning refrigerator or freezer before what’s stored inside is lost.

If fixing the issue isn’t possible, then there’s still the possibility of transporting everything inside to another freezer or refrigerator that is working properly.

Knowing when these problems are happening or about to happen is much better than finding out by walking into a lukewarm refrigerator or freezer.

Plus, it can save your organization a lot of time and money. Beyond the cost of lost materials or product and the necessary repairs, there are lots of other expenses that can be avoided or at least mitigated. These include regulatory fines, overtime costs for staff, and the loss of future sales for failing to complete an order or delivery.

Compliance: If an organization relies on refrigerators or freezers for their business, it’s likely they need to follow compliance standards from regulatory authorities, insurers, or both. This is definitely the case in the food & beverage and medical industries.

By automating the collecting of temperature data, businesses can reduce some of the more rote tasks involved with compliance. They can also ensure that their temperature records are more standardized and less prone to human error.

Inside of a commercial freezer

Detect Compressor Issues: By looking at the changes in temperature data over time, businesses can also assess the overall performance of the compressors that are cooling their refrigerators and freezers.

Is the freezer becoming slower to cool after loading new materials? Is the refrigerator’s temperature becoming more variable over time?

These sorts of assessments are almost impossible to make without a consistent record of temperature data. They’re also difficult to make when reviewing manual, handwritten logs of temperature data.

But with a freezer alarm and monitoring system, all the data can be graphed, presented visually, and subjected to other types of analysis much more easily.

Graph of temperature monitoring system data using Kosmos

That means it’s possible to see problems before they become emergencies. And the data can be useful for helping technicians proactively repair refrigerators and freezers. It can also be used to prove to the manufacturer that there is an problem with their equipment that may be covered under warranty.

How to Build a Freezer Alarm System (Tutorial)

Temperature monitoring system in a commercial freezer

Below is a step-by-step tutorial for building a temperature sensing and freezer alarm application using Temboo’s Kosmos IoT system and temperature sensors from NCD.

For the purpose of this freezer alarm system, we are going to use a wireless NCD temperature sensor because:

  • It’s low power.
  • It can be used for temperatures ranging from -40° to 85° Celsius.
  • It comes with batteries suitable for this range of temperatures.
  • It has a 2 mile line-of-sight range with it’s on-board antenna.
  • It includes battery level readings with every transmission.
Parts list for freezer temperature monitoring system tutorial

Setting Up Your Kosmos Account

  • Go to the Temboo’s website and create an account – don’t worry, you have a 30 day free trial.

Gateway Application Setup

  • First, install Etcher so that you can copy the Kosmos gateway application to your micro SD card.
  • Insert your micro SD card into your USB SD card reader and connect the card reader to your computer.
  • Open Etcher and drag the Temboo_kosmos...xz file to the micro SD card (you previously downloaded this file while creating your Kosmos application).
Etcher Image

Kosmos Gateway Hardware Setup

  • Insert SD Card
    • Insert the micro SD card into the underside of the gateway (the metal contacts slide in face up).
micro usb into the gateway
  • Power Up The Gateway
    • Connect the 5V 2.5A power adapter to your Kosmos
      gateway. Then, plug the adapter into a power outlet.
powering the gateway
  • Connect Ethernet Cable
    • Use the ethernet cable to connect your Kosmos gateway to an ethernet outlet. See instructions later in this guide if you want to connect your gateway via WiFi.
connecting the ethernet to the gateway
  • Connect NCD Modem
    • Connect the NCD modem to your gateway via the USB cable provided.
connecting the receiver to the gateway
  • Prepare USB Drive
    • Copy the Kosmos config file temboo_kosmos_config.ini onto your USB drive.
put the temboo_kosmos_config.ini to the USB
  • Insert USB Drive
    • Insert the USB thumb drive into any available USB port on your Kosmos gateway.
Put the USB into the gateway

Don’t forget – you can always ask us for help!

Powering On Your NCD sensors

  • Attach the antenna to your NCD sensor(s). Next, decide how you want to power your NCD sensor(s).
    • Wired power: connect the NCD power adapter (12V 3A) to the sensor and plug it into a power outlet. The sensor will automatically start sending data to your Kosmos gateway
    • Battery power: open the sensor’s enclosure and set the PS (power select) jumper parallel to the marking line on the board.
How to power on NCD sensor

Configuring your NCD Sensors

  • Log Into Kosmos
    • Log in to your Kosmos account and navigate to the Sensor Provisioning page. (Hint, its on the top right of the screen)
Device provisioning
  • Select Your Application
    • Select the Kosmos application that you want to set up. During this process we’ll configure your sensors to communicate securely at your chosen data frequency.
select device
  • Confirm Connectivity
    • After selecting an application you’ll see a screen displaying your gateway’s connectivity status. When your gateway is online you can move on to configuring your sensors.
      • Note: This can take up to 60 seconds. Check your social media real quick and when you come back, your temperature sensor should be online.
gateway connected page
  • Enter Config Mode
    • Your NCD sensors must be set to config mode before their settings can be updated.
    • To enter config mode, press the RST button for 5 seconds, release it, and then hold down the CFG button until your sensor has been provisioned (this typically takes about 25 seconds).
image of rest and config
  • Exit Config Mode
    • Once you’ve successfully provisioned your sensor(s), hold the RST button for 5 seconds
    • When you’ve finished the provisioning process you automatically will be taken to your dashboard to see your live data!
successful config
You’re a rockstar.

Connecting Your Gateway Via WiFi (Optional)

  • We recommend using ethernet to connect your gateway to the Kosmos web dashboard.
  • To use WiFi to connect your Kosmos gateway to the internet, first remove the USB thumb drive from your gateway and plug it into your computer.
  • Locate the temboo_kosmos_config.ini file on the USB thumb drive and open it with your favorite text editor.
  • Add the details of the WiFi network that you want your gateway to connect to (see lines 14 & 15 in the screenshot below), and then save your config file.
  • Eject the USB drive from your computer and insert it back into your Kosmos gateway. Remove the gateway’s power supply and reconnect it. Your Kosmos gateway will power back up and connect via WiFi.
wifi setup

How to Get the Best Readings from a Temperature Sensor

Once your temperature sensor is online and transmitting data to Kosmos, you’ll want to deploy it in the real world.

The first thing to think about is placement. Where should the temperature sensor be located?

You’ll need to find a location in your refrigerator or freezer that isn’t in anyone’s way. You’ll also want to find a location that gives the most accurate readings, so you’ll want to avoid locations close to doors or that are far away from the materials being stored.

In some cases the temperature readings may not be what you expect because the sensor is too sensitive to temperature fluctuations. In such cases it’s best to try out different locations to see which ones provide the most accurate readings.

It can also be helpful to insulate your temperature sensor if the readings are too sensitive to temperary changes. There are a variety of ways to do this. Encasing it in foam or a nylon block, placing it among jugs of water, or using glycerol are all common methods for buffering temperature sensors.

A Note About Connectivity 

Connectivity may be an issue if the gateway is located too far away or if there are thick walls between the gateway and sensor.

If the temperature sensors are not communicating with the gateway, then you can add a “repeater”. A repeater extends the radio waves of the sensor to reach the gateway beyond its normal capacity. But it’s best to first try out different placements of the gateway and sensors to see if you can resolve connectivity that way.

Temperature Monitoring and Freezer Alarm Systems at Your Organization

Temperature monitoring system using Kosmos on a computer, tablet, and phone.

If you are working at an organization that needs to monitor temperature and set up freezer alarm systems we want to help. We also offer special programs and discounts for using Temboo’s Kosmos IoT System for environmental monitoring applications that contribute to sustainability, legislation changes, or community improvement.

For more information, contact us at