ELEKTOR FORUMS

I don't know how much difference it would make, but this ckt is missing an important ingredient for accurate measurements. In an effort to avoid the expense of some types of temperature sensors, the author has overlooked the need to compensate for two other thermocouples in his circuit - the connections to the thermocouple. Those junctions, being of different materials, will generated a voltage that should be subtracted from the sensor readings. Usually this done with a cold junction compensator, which is provided as part of the connector in the multimeters referred to in his article.