Application
Temperature measurement requiring chemical resistance
A customer required a batch of PT100 temperature sensor assemblies for use in an environment where part of the sensor and cable would be exposed to an aggressive medium.
The challenge was to provide the necessary chemical protection while maintaining a tightly controlled finished diameter and avoiding unnecessary material and processing costs.
The Challenge
The customer supplied the completed PT100 sensor assemblies to Adtech for encapsulation.
Each assembly had a 3mm outside diameter and an overall cable assembly length of 3,000mm. The finished coated assembly could not exceed a maximum outside diameter of 3.4mm, making control of the FEP coating thickness particularly important.
Although the complete assembly measured 3,000mm, only the lower 2,000mm would ever come into contact with the aggressive medium during operation.
Encapsulating the entire length would therefore have added material and processing cost without providing any additional protection where it was actually required.
What Adtech Did
Adtech encapsulated the specified section of each free-issue PT100 sensor assembly with 0.2mm FEP.
The FEP encapsulation was applied to 2,000mm of the 3,000mm assembly, extending above the maximum level that the aggressive medium would reach during use.
This approach provided chemical-resistant protection across the section exposed to the medium while leaving the remaining 1,000mm uncoated.
It also allowed the customer to reduce the cost of the finished assembly by only applying FEP where it was needed.
Particular attention was paid to dimensional control. With the original sensor measuring 3mm OD and the finished assembly limited to a maximum 3.4mm OD, the 0.2mm FEP thickness provided the required protection while keeping the completed component within specification.
Technical Specification
- Component: Free-issue PT100 sensor assembly
- Application: Temperature measurement
- Original sensor OD: 3mm
- FEP thickness: 0.2mm
- Overall cable assembly length: 3,000mm
- FEP encapsulated length: 2,000mm
- Maximum finished OD: 3.4mm
- Batch quantity: 150 assemblies
The Result
Adtech produced a batch of 150 FEP-encapsulated PT100 sensor assemblies, protecting the section exposed to the aggressive medium while maintaining the customer’s critical dimensional requirement.
By limiting encapsulation to the 2,000mm section that required chemical protection, the customer also avoided the additional cost associated with coating the full 3,000mm assembly.
The project demonstrates how fluoropolymer encapsulation can be tailored around the actual operating conditions of a component, combining chemical protection with precise dimensional control and more efficient use of material.
