Assembly and encapsulation of temperature sensors

Did you know that the assembly and encapsulation modality is vital for the successful operation (according to its specifications) of the RTD sensor of temperature?

Typically, the RTD sensors are assembled on stainless steel casings or ceramic tubes to provide protection and isolation, if these tubes are installed on applications where measurement and monitoring take place. Besides the assembly, the choice of isolation material applied between the internal wall of encapsulation and the sensor element is of utmost importance, since that, the more conductive the insulating material is, the greater the chance that the mounted sensor will have low insulation.

When assembling an RTD platinum temperature sensor, which comply with the specifications of the Regulation IEC 60751, an isolation of 20 M Ohm for temperatures of up to 250°c should be considered. To achieve the standards specified in the regulation, the isolation materials between the ohmic resistance and the encapsulation walls should be capable of:

- Bear the temperature without any change in its properties, since the alteration of characteristics of this material may hamper the isolation of the assembled sensor.

- Offer mechanic protection of the resistance piece, thus avoiding external influences on the sensor reading, such as humidity.

There are many ways of assembly for temperature sensors, each one with its specific method or material, however, on every assembly, the care with isolation and consideration to the conductive parts, besides the appropriate handling of the part are vital for the sensor good operation and durability. There is a suitable form of assembly for each type of application. The customization of the sensors should always consider the critical points and characteristics of each application to achieve the best sensor performance, combined with longer durability, as an example, harsh environments require greater attention regarding the materials to be used, while an assembly for use in wet environments requires greater care in isolating the sensor element. Each peculiarity is followed by a special need, applications of difficult access to the sensor, it is recommended the use of a double sensor (reserve), if there is vibration, the care of fixing the sensor element in the encapsulation is extremely important.

Sensors assembled by Sensor Technology have such a quality control that we ensure that all assemblies are properly insulated so that 100% of the items supplied can be immediately used by our customers without any doubt regarding their operation.

Please contact us and send us your specifications, so that together we can develop a product that is completely suited to your needs.