How Can You Monitor Temperature?
The customers that benefit the most from using the system are general contractors. They are many gains to make and these can be classified into two broad categories:
Temperature Monitoring Solutions
In broad terms, there are two main types of solutions in the market. The first are traditional data loggers. These type of devices normally consist of:
- A central unit, where the temperatures are displayed and where a USB cable can be connected to download the data.
- And thermocouples of diverse types and lengths, which will be placed into the concrete to measure the temperature.
The second type are concrete sensors. These vary in shape and functionality but normally consist of:
- A transmitter and/or a sensor, that collect the data and either save it locally or send it to the cloud
- An online platform, here the data sent from the sensors is displayed in graphs and reports.
Installation
The concrete sensors can be broadly classified in:
Wired sensor solutions
Wired sensor solutions, either using thermocouple sensors or custom-made sensors with internal memory, are attached to the rebar and connected to a data logger or transmitter. The sensors are then embedded into the concrete while the data logger or transmitter stays outside the concrete.
Wire-free sensor solutions
Wire-free, these sensors combine the sensor, internal storage, and transmitting electronics in one single device. These are usually attached to the rebar and are fully cast into the concrete.
Reusability
Reusable components
When using wired sensors, the data logger or transmitter stays outside the concrete which means that these can then be reused again and again.
Non-reusable components
When using wire-free sensors, all the components, which are contained in a single device, are embedded in the concrete. Therefore, you lose one device in every monitoring.
The major characteristic setting apart the different solutions is the way that the data is collected. This is important because some products will require you to be close to the sensor to collect the data while others can send it directly to the cloud. This is explained below:
Data Collection
When using data loggers, you or someone on the team needs to personally get to every sensor and obtain the data manually.
When using wire-free sensors, to get the data you need to be on-site to connect to each sensor via Bluetooth (distance max. 8 meters).
When using wireless transmitters, the data is available from anywhere, as the measurements are sent to the cloud continuously – with no need to be on-site to collect measurements.
How To Choose the Best Solution For You?
The range of options within temperature monitoring solutions have been expanding rapidly in the past few years. This makes it harder to get a clear overview of what is important and which solution will suit your needs better. In general, we advice to keep these basic recommendations in mind:
- The sensor and data transmitter (might be the same unit) needs to be robust, as it needs to operate in a tough, wet and alkaline environment.
- The embedded part of the sensor should have a low heat capacity and thermal conductivity so it doesn’t affect the temperature locally inside the concrete structure where you measure
- The measurement intervals need to be short enough to monitor any temperature variations
- The sensor needs to be easily and securely mounted before the concrete is poured on top.
- The sensor monitoring needs to be reliable and has the required measurement tolerances.
- You should be able to easily repeat the same method every day with a high degree of certainty
- The system should be affordable, so you are able to use it multiple times and on most of your castings, so you gather data and learnings across your concrete mix designs and cast structures
After you find a solution that satisfies the recommendations above, you may still have plenty of available choices. You can narrow these down by considering:
- What is the aim of my monitoring (documentation, formwork removal, temperature variations in cross-sections, etc.)?
- Where do I want to measure?
- How often do I want temperature readings?
- How do I want my data to be collected (manually vs. wireless vs. remote wireless)?
- How do I want to process my data (Excel, automatic online platform etc.)?
- What is the maximum cost for monitoring that I am willing to pay?
Having a clear answer to these questions will make it a lot easier for you to make the right choice of system. This way you will avoid choosing a system that doesn’t fit your requirements or which might be too big and expensive.