Mineral Insulated Cable for Induction Furnaces Avoids Errant Signals

Problem:

Packaging machine manufacturers have a variety of needs as far as temperature sensing goes. In this particular application, the customer's primary packaging machine packages bologna.

The customer requires a small diameter thermocouple to measure temperature just below the face of a moving die. The thermocouple must be ductile enough for bending in the field to thread the thermocouple junction into the correct temperature sensing position. The thermocouple must also be rigid enough to hold its shape and maintain a clearance distance from moving parts. No portion of the thermocouple may be larger than 0.125-inch (3.2 mm) diameter due to a clearance problem situation built into the equipment. The problem is compounded by the fact that the customer has many pieces of equipment in the field that have antiquated analog temperature controls that require a specific resistance value to the thermocouple circuit.

Solution:

The sales engineer and the product manager worked closely with the customer and through a series of prototypes, were able to design a cost effective mineral insulated Type K 0.062-inch (1.6 mm) OD thermocouple that is terminated to leads with a shrink-fitted adapter that does not exceed 0.090-inch (2.3) diameter. The use of an MI cable type thermocouple enabled Watlow Gordon to provide the customer with a fully annealed (easily formed) thermocouple in exactly the correct dimensions and resistance required by the application.