A furnace as we all know is an oven or a place where heat at extreme points are created. Furnaces can be of many kinds, beginning from the ones which are used in residences to the industrial varieties which are primarily accompanied with conditioning of metals-alloys, ores etc.
The furnaces used in houses (also called boilers) have only features for raising the temperature of the room to appropriate levels and are thus do not accompany crucial temperature levels for the intended reasons. With industrial furnaces though, if the temperatures tends to deviate might give rise to serious consequences and
Please refer the CIRCUIT DIAGRAM to better understand how to make a high temperature sensor device.
We all probably have a lot about thermocouples and how these devices function. We precisely know that when a couple of dissimilar twin metal units are joined at one of their ends and heated, their other free ends develops a potentials across them, which might be proportional to the rising or varying heat levels at their joined ends.
This basic thermocouple principle has been employed for this project which is definitely quite easy to construct and use as a pyrometer or furnace temperature detector.