Thermometer

Turns "glowing orange" into a number.

Crafting

G
F
P

G is a Glass Pane, F is Copper Foil and P is a Copper Plate.

Using it

Carry it anywhere in your inventory. You don't need to hold it.

• Hot items show a temperature in Tu on their tooltip instead of a colour word.
• Crucibles, cable, the Improved Furnace and other open blocks show a figure in Jade.

Right-click any hot block, even a sealed furnace, to take one reading through the door. Sealed furnaces can't be watched (Jade just says "Sealed - cannot be measured"), but you can always check them by hand.

It's rough

The thermometer reads in steps of 25 Tu. Steel's window is 60 Tu wide, so it's about two steps: you'll know you're in it but not exactly where. It's still enough to make steel reliably by hand: heat, check, wait, check, adjust.

For finer readings, and readings a Controller can use, bolt a Temperature Sensor onto the vessel.

Why it matters

Before the thermometer, "hot" is all you've got. Nothing is locked behind it; you can make steel without one if you're lucky. What it gives you is the ability to do it on purpose.