A simple way to make thermocouples for use as temperature sensors

To measure the temperature of the tip of an electric soldering iron, melt in a bath of tin wires measuring the heating temperature of electric machines, etc. in repair and amateur practices, thermocouples are used... I suggest you familiarize yourself with two of the simplest methods for making thermocouples.

1. Pour coal dust into an iron crucible with a metal support — broken arc electrodes or galvanic cell electrodes. One end of the electrical wire from the crucible is connected to the terminal autotransformer (LATRA), another electrical wire from the autotransformer is connected to the twisted thermocouple, which we clamp with pliers with insulated handles and supply voltage from the autotransformer is about 60-80 V.

Twisted wires (for example chromel-copel with a diameter of 0.3-0.5 mm) dip in coal dust to which a little flux (borax) has been added, in which a small electric arc, and the ends of the thermocouple welded, forming a ball at the ends of the wires.This welding method is suitable for welding chromium-aluminum, copper-constantan and platinum-platinum-rhodium thermocouples, coils of heating elements and wires of windings of transformers and electric motors.

2. We twist chromel-copel wires with a thickness of 0.3-0.5 mm to a length of 6-8 mm. When welding, we grip the twisted and cleaned ends, as in the first fashion, pliers with insulated handles. Dollar voltage We bring the 12 V transformer to the handle of the pliers and to the carbon electrode. When the carbon electrode touches the twist, the ends of the wires melt, forming a ball at the end.