Got a new water kettle that has different temp selections for different teas. If you select a less than boiling temp, it’s smart enough to stop heating early, wait for the termometer to catch up, then give another burst of heat to reach the target. Fair enough.
OTOH, if you boil water, it does not bother to stop and read. Perhaps prioritizing speed over energy waste. When the water is bubbling like crazy, it’s clearly boiling at which point the thermometer shows 90°C. So it keeps heating to 100°C. Are thermostats generally that slow and far off? Or is my kettle’s thermometer particularly slow?
Low tech electric kettles which only boil the water have no thermometer AFAICT. Is it steam that triggers the off switch? Would that be faster than a thermometer that is 10° behind?
6 Comments
rbn@sopuli.xyz · 6 pts · 1d
Normal kettles have a piece of bi-metal that chabges its shape and thereby triggers the switch once it's getting hot enough. This happens in my experience with a delay of around 10 seconds.
cynar@lemmy.world · 4 pts · 20h
Most now use a different method. The thermal cutoff has problems when the air pressure is lower than expected. It can get to a rolling boil, but never turn off.
Most now use the presence of steam coming off the liquid. This means it gets to a boil, no matter what temperature that actually is. I've seen a demo where they put alcohol in, and it worked fine, despite boiling at only 78°C.
rbn@sopuli.xyz · 4 pts · 20h
Ah okay, thanks for the hint. I attemted to repair two broken ones last year (one successful) and they both used the 'old' bi-metal technology. So I assumed that to be the 'standard'.
cynar@lemmy.world · 3 pts · 19h
A lot have them as a fall back. If they boil dry, they overheat and trigger the cut off. It's a fail-safe however, rather than the primary mechanism. It's also possible some use a bimetallic strip as part of the steam detection system.
tetris11@feddit.uk · 0 pts · 22h
the day we started using LGBTQ electronics is the day that we invented precision tea
cynar@lemmy.world · 3 pts · 19h
I've personally resorted to using a thermal camera for green/white tea water temperature. I'm aware it's a little overkill however!