Crysto-Jello is Jelly (Jello) with heat-sensitive(colourising) crystals mixed it.

Fill a bowl with warm water and mix in the Crysto-Jello, and leave to set.

Place the bowl in your microwave on full for ~20secs, and remove the bowl.

Look or Slice through the (now colourised to reflect the heat absorption throughout the substance) to see whether your microwave is generating hot-spots (possibly indicating that adjustment or replacement is required).

A square-mold with the middle cut-out can be leaned-against the door to check for dangerous microwave leaks too.

Must go now... the mycelia, tides, and oysters are calling....

*No Magnetometers were harmed during the inception/elaboration of this idea.
-- Dub, Sep 20 2005

Microwave Oven Hot Spot Test http://home.earthli...wave/microwave.html
See the section covered by the "Wet Thermal Fax Paper Test" for another graphic demonstration of your microwave oven's hot and cold spots. [jurist, Sep 20 2005]

Thermal Thinking (Silly?) Putty http://www.puttywor...m/usethputofis.html
Measure the speed of light with with the stuff, too. [Dub, Nov 03 2005]

Curses! Baked http://amasci.com/w...e/voltage2.html#map
via HB "microwave oven experiments" [Dub, Nov 29 2006]

Array of Neon bulbs in a microwave http://www.youtube....watch?v=kAAXpKdQ-mk
[Dub, Nov 23 2010]

I guess this could be made by dispersing a thermochromic ink in a clear gel. I think a matrix of thermochomic elements embedded in (or seperated by) a material of lower thermal conductivity might work better because it would (thermally) isolate the hot spots.
-- xaviergisz, Sep 20 2005


if it ain't broke don't fix it.... (ie, if your food warms up eventually then your microwave is probably fine so why waste your time?)

Would be fun though ... so I'm .. undecided and neutral
-- ixnaum, Sep 20 2005


In this instant world, surely a pre-made mat or rectangular plate would sell better than something you have to mix up? Simply pop mat in oven, switch on for ten seconds, and hot spots will appear as, say, red coloration.

But I am not sure what use this information is. Most microwave instructions include turning the food partway through cooking, precisely to avoid hot spot issues. And people with turntables in their ovens surely don't need to worry about it.

jurist: cool link. I've done the grapes and CDs, but there are some neat tricks there with ball lightning and molten Pyrex that I have to try out...
-- DrCurry, Sep 20 2005


[jurist] Like the CD in the microwave. How many time have I got my conumer electronics mixed up? Pizza in the Video, DVD in the CD player...

[DrC] I thought it'd be cool to be able to slice it through. It's a test thing rather than a fix. Also, if you find that the hotspot is dead central, turning it won't make any difference.
-- Dub, Sep 20 2005


For that reason, I always move the food in the microwave about as well as turning it.
-- DrCurry, Sep 20 2005


Sorry DrC... I looked at it, and it broke! :< Hopefully back the way it should be now... I had a mad 5mins- I'd blame the moon again.
-- Dub, Sep 21 2005


[DrC ]Ah, but how do you know you're not moving the food to a part that doesn't cook very well?
-- Dub, Sep 21 2005


It comes out hot, duh. (And if it doesn't, I put it back in and microwave it some more.)
-- DrCurry, Sep 21 2005


[DrCurry]Well, double-duh, bits of it MIGHT come out hot, but the important bits, those that you really want the e.coli zapped from, might just be at a nice luke warm and ideal-for-incubating young e.coli temp.

Tell me, Is this just a 5 minute argument, or the full half-hour?
-- Dub, Sep 21 2005



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