Wired Temperature and Maturity Loggers
To address some of the deficiencies in thermocouple-based systems, wired temperature and maturity loggers were developed. These loggers and meters have an electronic circuit board that contains a coin-size battery with an onboard thermistor (typically an NTC type sensor) for temperature measurement. The measurements are recorded and stored on this circuit board at pre-defined intervals. The whole circuit board is completely sealed with a connector wire coming out to download the measurements using an external device as needed unlike the thermocouple-based sensors that need to always be connected to external data recording equipment.
The wires used for these types of temperature/maturity loggers are more rugged compared to thermocouples which makes them less prone to damages on the jobsite. The external unit is also not exposed to potential damages in a constriction environment as it is used only when downloading the data. External devices can offer various types of data analysis in the field. But, for full analysis and report generation, the data needs to be downloaded later on to a computer.
Even with some improvements from thermocouples, wires temperature and maturity loggers do present some disadvantages such as:
- No electrical switch and are always turned on, resulting in a limited shelf-life
- Industrial-grade connector cable makes the sensors bulky and difficult to install
- Wires need to be labeled for identification after pouring and has to be protected on the jobsite
- It is challenging to find the cable lead during the first few days of pouring

Wired Concrete Sensors with External Wireless Transmitter
Using wired temperature and strength sensors requires expensive data loggers to retrieve this data. An individual must find each wire connected to a sensor and retrieve the measurements with the loggers. As a result, wires are often damaged or cut. Furthermore, the loggers are required to stay on-site where they can easily get damaged with exposure to humidity. When monitoring temperature at various spots for one concrete pour, the wires are accumulated in one location for ease of access. However, this can create a hassle of identifying and labeling them.
Moreover, the assembly of thermocouples requires some attention to detail! If not conducted properly, wires can cross over in the plug and cause reading errors. Once the data is logged, this information must be synced to a device, such as a laptop or desktop, where it must be analyzed by an experienced individual. That can take significant labor hours, depending on experience.

Fully Embedded Wireless Concrete Sensors
With a wireless maturity sensor, the device is fully embedded on the rebar before pouring. The installation is simple and hassle-free with no protruding wires. Data is collected via Bluetooth on a mobile device or tablet. This eliminates the need for a data logger. With SmartRock, the data collected by the sensors is updated every 15 minutes and uploaded to the iOS or Android app. This data, as well as measurements provided during mix calibration, is used to determine the maturity/ strength of the in-situ concrete in real-time. With the SmartRock app, this data can also be easily shared with team members.
Therefore, no additional labor is needed to calculate when further steps can be taken. In this way, non-destructive wireless concrete temperature sensors and maturity meters, such as SmartRock, have been developed for the concrete industry to reduce labor costs. These wireless systems can therefore significantly improve the efficiency required in fast-paced construction projects.

Learn More About Wireless vs. Wired Sensors Here
Choosing the Right Maturity Meter for Your Jobsite
There are several options for purchasing a concrete temperature/maturity sensor for monitoring the concrete curing and hardening in your concrete project. This gives contractors a wide range of options for selecting maturity meter based on cost, accuracy, and ease of use. Check out this blog to view a list of various commercially available concrete sensors, temperature loggers, and maturity meters.