Measurement Method
Non-contact temperature measurement utilizes infrared sensors to track the surface heat of a moving fabric during thermal processing. Drying lines implement pyrometric thermal monitoring to detect temperature variations across the width of the fabric without touching the sensitive wet surface. This method provides real-time data that helps prevent over-drying and dye migration.
System Mechanism
The sensor detects the infrared radiation emitted by the hot textile and converts it into an electrical signal that corresponds to the surface temperature. By scanning across the moving fabric width, the system maps the temperature profile of the material as it exits the pre-dryer. This pyrometric thermal monitoring allows the control system to detect damp spots where evaporation is incomplete.
When the temperature profile deviates from the target, the system automatically adjusts the power of the heating emitters.
Operational Control
Calibrating the sensor emissivity is critical to ensure accurate readings for different fabric types and compositions. Technicians mount the infrared sensors at a fixed distance and angle from the fabric path to prevent reading errors. The pyrometric thermal monitoring system must be protected from dust and steam by using compressed air to keep the lenses clean.
Regular comparison with contact-type reference thermometers verifies the system accuracy.
Process Constraint
This monitoring method can give inaccurate readings if the fabric surface has high reflectivity or if the fabric moves irregularly. It is also unable to measure the internal temperature of very thick, multi-layered fabrics.
