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True. How can this be used? Heat is added and the temperature rises until a plateau is reached, then you know it's boiling. It could be a method for determining the boiling point. But if I had a temperature sensor on my egg-cooking kettle I'd turn on the heat anyway as soon as cooling is noticed.
Though the boiling temperature of the water can vary significantly, what we do know is that the temperature of the water no longer increases when boiling is reached. That can be used as an indicator for boiling.
So other than using a calibrated temperature sensor for this egg cooker can anyone suggest another economical method to detect boiling water? I am sticking with temperature, rest assured, the eggs will cook.
Water freezes at 0C or 32F and that is as cold as it gets...
RE, cooking eggs.
I don't see a reason that it can't float at 99~101C and not cook eggs. I also agree that it may even be more efficient.
Ah, sorry, I see that now. I live at sea level (well, 160ft ~50m) so any variation will be due to weather and probably too small to make a difference here. Not many live below sea level and many live above where boiling point (BP) will be less than 100°C."99~101°C" was my funny little way of taking into account atmospheric variation. You could theoretically be under higher than normal barometric pressure, or you could happen to be in some rare, lower than sea level place like death valley. Both of which would raise the boiling point of water ever so slightly above true 100°C. Which is ironic because 100°C is exactly defined as the boiling point of water... [SUB](at sea level)[/SUB].
Maybe the aim of keeping it at BP is hard to achieve?
PS:
No Monk movie! Not sure what happened and cant find any more info on this.
Some interesting thoughts but I can see a problem or two. If the heater is controlled proportionally rather than on/off, you need a more complex analogue current control. It can be done with phase delay triac triggering but at 2-3kW it would create a lot of electrical noise. Also it would take longer to reach BP if you keep holding back as you get near the target temperature. And if you don't want to measure temp, what would you differentiate?Without having to know what the actual temperature is, some sort of circuit (a differentiator circuit, perhaps) to monitor the rate of change in temperature of the water can be used to turn the heat on and off. If the rate of change (either increase or decrease in temperature) is below a certain (small) threshold level, the heat is turned off, otherwise heat on. I think what will happen, however, is that the water will be kept just at the boiling point, which is where small bubbles start to form at the bottom of the kettle and there will no rolling boil. But, does that matter anyway?
I hate to admit it but I'm just happy to know you should start with room temperature water. Will this make them easier to peel?
Some interesting thoughts but I can see a problem or two. If the heater is controlled proportionally rather than on/off, you need a more complex analogue current control. It can be done with phase delay triac triggering but at 2-3kW it would create a lot of electrical noise. Also it would take longer to reach BP if you keep holding back as you get near the target temperature. And if you don't want to measure temp, what would you differentiate?
From my pov if we measure temp and get a signal to a control circuit, my choice would still be a μC so you can monitor it, drive a display, record data while 'tuning' the process. Some may prefer an analogue alternative or just use a bi-metal strip and timer to cut off when the time's up. I suppose we all lean towards what we're familiar with.
I've thought about the bubbles too. I made some tea earlier in the kettle I currently use. I usually hover and turn it off just as it comes to the boil but with this thread in mind I let it go on a few more seconds and the sound of the bubbles got much more vigorous and loud as it properly boiled. I still believe that's when it reaches BP and the greater vigour is due to the now excess power no longer being needed to heat the water now goes into vapourising some of it.
BTW i was trying to figure out what your (Oblivion) sig line means but cant quite read all the symbols or figure it out...some explanation perhaps? Thanks. Is that a line from Eight Legged Freaks or something?
Hummm.... It may not be showing up as the right characters on your system. Here is an image of what it looks like to me...
View attachment 70588
It is just ASCII art of a funny little guy being mad or scared and throwing a table because of it.
Edit:
BTW, in case you're also wondering, my avatar is the Japanese Kanji "忘却" which in hiragana is "ぼうきゃく" and in romaji "Boukyaku".
All of which of course ultimately equates to..... "Oblivion". (Can also mean "forgetfulness".)