Automatic Capacitive Welding Equipment for Thermocouples

Abstract

Thermocouples are electrical devices of simple design used in temperature measurement and have great use in industry. The thermocouple needs an efficient junction for the two metal wires, commonly done by welding. The welding process can be done in several ways, and the most common and efficient is the capacitive discharge welding, that will fuse the alloy and create a joint, maintaining the metal properties and results and a homogeneous joint. This work aims to develop an equipment capable of performing automatically this welding, by capacitive discharge, in inert environment, whose value of energy to be discharged is determined using the principle of conservation of mass and energy in pre-established alloys and gauges of some types of thermocouples. The results obtained with the welding of different types and thermocouple gauges were analyzed according to visual aspect and image analysis software along calibration curves. The thermocouples were considered of good quality according to analysis parameters established, and comparation to commercial thermocouples.

Key-words:
Thermocouple welding; Capacitive welding; Welding equipment