Cooking Thermometer: Candy Thermometer in a Glass Tube with a Venting Plastic Cap (Chaney, US 3,636,769, 1972)

A candy and deep-fat thermometer that clips to the side of a pan. A glass thermometer on a printed scale card sits inside a protective glass tube, so it never touches the candy. The top of the tube is closed by a polyethylene cap that seals in normal use but softens when the whole thermometer is heated far too hot, as in an oven, so the air inside escapes instead of bursting the tube. Result: a pan-side cooking thermometer that cannot explode if overheated. Source: J. L. Chaney, US 3,636,769 (1972). Unknown: the scale range, sizes and several materials. Picture: the patent drawing.

중급

Unknown

안내

Mount the thermometer on its scale

Fasten a glass thermometer tube to a graduated scale card with small fasteners, the bulb at the bottom. The patent's card is marked with cooking points such as soft ball, hard ball, soft crack, hard crack, fish, fowl, potatoes and doughnuts. Fix a disk on top of the card to keep it centred in the outer tube. Not given: the range, the card and fastener materials.

이 단계의 재료:

실험용 온도계1 thermometer tube

알 수 없는 재료1 scale card, disk

알 수 없는 금속1 fasteners

필요한 도구:

알 수 없는 치수

Enclose it in the protective tube

Slide the card and thermometer into a glass protective tube, open at the top, so the bulb reaches the lower end and touches a metal cap there to pass on the heat. Not given: the tube size, the metal of the end cap, how the cap is joined to the tube.

이 단계의 재료:

유리관1 protective tube

알 수 없는 금속1 end cap

필요한 도구:

알 수 없는 치수

Fit the venting cap

Close the open top with a cup-shaped cap of a thermoplastic such as polyethylene, a friction fit that seals out dirt. Polyethylene softens at about 180 °F and melts near 250 °F: if the thermometer is heated in an oven to 400-550 °F, the air inside would reach 12-14 psi, but the cap distorts first and lets it out. Do not use rubber or a thermosetting plastic, which does not vent. Ours: LDPE.

이 단계의 재료:

LDPE 펠릿1 cap

필요한 도구:

알 수 없는 치수

Fit the pan clip and use it

Slide a spring clip onto the outside of the tube; its spring arm holds the thermometer upright over the edge of the pan. Clip it on with the bulb end in the candy or fat and read the scale; it also serves for deep frying. Ours: spring steel wire.

이 단계의 재료: