Tiny Screws Serve As Thermometers
December 1963…
New screws an eighth of an inch long can be set in pistons, connecting rods, and other moving engine parts to check operating temperature without the expense of thermocouples.
Developed in England by Shell Research, the alloy Templugs screw into tapped holes, and record heat by a permanent change in their hardness.
Measurement on removal indicates heat up to 1,800 degrees with one-percent accuracy.
