Wednesday, January 27, 2010

Thin wire.

I’m still discovering new ways to break thermocouples. Fortunately I’m becoming quite adept at making them, so it’s just a matter of making them and breaking them until I’ve figured out all the ways of breaking them so that I can avoid those.

I’ve discovered that if I drag the thin wires around sharp edges it makes them much more fragile.

Edit: Latest thermocouple ready for installation …

Thursday, January 14, 2010


Today I discovered that high-pressure carbon dioxide can blow a microthermocouple out of its capillary if the end of the capillary is not sealed. This possibility never occurred to me. I fact, I never realized that the pressure inside the tube where I want to measure the temperature would be pretty high.

While this is a disappointment, it also suggests a new way of getting the wires inside the capillary in the first place.

Tuesday, January 12, 2010


Practice, if it does not make perfect, at least helps a lot.

Last year, in a long slog, it took me weeks and many mistrials to learn how to make a microthermocouple by welding two 20-micron wires together. (At that thickness it’s so thin it is impossible to feel it if you hold it between your fingers.)

Today I made a micro-thermocouple in a leisurely morning.