Contactless temperature measurement of thin wires: methods comparison

This work describes the design of two contactless temperature measurement methods based on total radiance and two-colour pyrometry. The methods have been conceived to measure the temperature of a small brass coated steel wire during wire drawing. Usual contact sensors cannot be applied due to the wire movement and excessively large insertion errors in this critical condition. The pyrometers optical layouts have been analysed by means of numerical simulations in order to evidence their sensitivity to the wire oscillations. Performances of different infrared sensors have been compared on the basis of the achieved measurement uncertainty simulating background temperature variation, slope of the wire???s emissivity and the effect of the atmosphere absorption.