Why does a Meat Thermometer not need Tevilla?

Question

In this answer, We were told that "according to the Star-K Tevila Guidelines, no tevila is required for a meat thermometer."

Why not?

From the Star-K's article on Tevillat Kelim:

Utensils require tevila with a brocha when they have direct contact with food during preparation or meal time and are made from metal such as aluminum, brass, copper, gold, iron, lead, silver, steel, tin, or glass such as pyrex, duralex, and corelle.

Isn't a meat thermometer metal, and doesn't it have "direct contact with food during preparation"?

The article also mentions:

Utensils used exclusively with raw, non-edible food, for instance cookie cutters or a metal tenderizer hammer do not need tevila.

One could argue that this would apply to a meat thermometer as well, but is a meat thermometer only used with raw, non-edible food? Isn't it also used to measure when the meat is done cooking, which would mean that the meat was in an edible state?

Answer 1

http://www.youngisrael.org/content/PDFs/Halacha_Central/Halochoscope/hs14-10a.pdf

A thermometer is used for a different type of measurement. The operative term is tikun ochel, accomplishing some positive change in the food. A utensil used to measure ingredients or portions performs such a function. A thermometer is used to decide whether the food should be brought closer to the fire or the heat should be increased or decreased. These seem to have little direct connection to tikun ochel. In earlier times, such utensils did not exist. This is similar to a utensil used to poke food to see whether it is fully cooked. It is also not being used in a conventional preparation application. It seems that its entire use is to touch the food, rather than to add any steps in its preparation. The Talmud discusses the kli status of a reed used to measure the depth of a cistern of wine, or water. Another type of reed was used to determine whether the olives in a ripening tank were ready to press. These measuring tools resemble the thermometer. However, there is no discussion on whether a metal tool serving these functions requires tevilah as a food preparation item. In the absence of any discussion by the poskim, it would appear that this utensil does not require tevilah. If one were to tovel it, one should not recite a brocha. [See Kailim 13:6 15:4 Shabbos 60a Avoda Zara 75b, Poskim. Tur Sh Ar YD 120:1 4-7 10, commentaries [Darkei Teshuva]. Hakashrus 4:18-21 32.]

Answer 2

The OU writes

The general rule is that any utensil, made from metal or glass, which touches the food and is used for preparing, serving, or eating the food requires tevilah. Though a can opener and a meat thermometer will come in direct contact with food, they do not require tevilah, since they are not directly involved in preparing the food. Although they are useful tools, they do not actually cook or change the food in any way. (See Shach, Yoreh De’ah 120:11.)