Microwave Oven field probe

Anyone ever seen a way to test the strength of the electric field at various points in a microwave oven while is is operating? I was thinking of some sort of thin coax with a loop probe at the end, and maybe a coax sliding choke joint at the door?

Also, anyone know any ideas on how to get any stuff stuck to the walls of the oven to heat up? Searching the literature yields interesting items like live ants can safely walk around inside of the over as they avoid the hot spots and are at the metal surface where the Efield is very small. So, if some nasty stuff was stuck to the wall of the oven, how could I get it to heat up?

don't know about your first question.
if I understood your second one, you have some stuff on the wall and want it to heat? well if that's the case just wet it with some water, as you know the MW oven works by resonating the water molecules and that generates heat, so if you put a wet thing in the oven it will heat up more than the same thing but dry, so I think that if you'll wet you nasty stuff with water and then operate the oven tha stuff will heat up nicely.
tell me how it went

Thanks.

The 2.45 GHz being a "resonant frequency" of water is an urban legend. 22 Ghz is a resonant frequency of water. At 2.45 the microwaves will generate heat, but due to simple frictional forces in the water molecule, not any resonance.

But the problem I am dealing with, and my EMAG theory days are long ago so this is from memory, is that the Efield at the metal walls of the oven goes to zero. There might be a lot of surface current in the wall, but if the wall is a good conductor, that does not heat up the wall or anything small that is stuck to it.

Added after 1 minutes:

"Water molecules in the gaseous state are free to rotate around any of three orthogonal axes. That such molecules can absorb energy consistent with a rigid rotor model given allowed energy levels suggests a phenomenon similar to that of electronic and vibrational energy transitions. Water in the liquid state suffers continuous intermolecular interactions owing to the close proximity of other water molecules. The allowed energy levels are said to be somewhat "fuzzed out" allowing energy absorbance within whole bands of energy in the microwave region of the spectrum. The microwave oven takes advantage of such a band structure. The frequency of a microwave oven is 2.45 GHz, and, as it turns out, NOT exactly centered on a resonant frequency for the water molecule. Had a resonant frequency been selected, most of the radiation would be absorbed by water molecules at the surface and the interior of the food would remain cold. Lower frequencies would penetrate better but not cook as well. Higher frequencies would not penetrate as well. 2.45 Ghz was chosen because of non-interference with assigned electromagnetic spectrum assignments for communication, convenience in implementation and reasonable penetration of the microwave energy into the food. " from the web

I remember reading some kid in the UK did a science fair project to map the standing waves. He sprayed paper with a chemical that changed color when heated, then sampled several heights in the oven to build up a 3D pattern. Also heard it could be done with marshmallows. Maybe an array of those little neon pilot lamps woud work to.

Yes, some of the things I found on the web were:

thermal printer paper lightly dampened

Small marshmallows spread around (although one report said they did not work)

Small ice cubes spread around

These are all good for a coarse measurement, but I am trying to actually get a meter reading out of each x,y,z position.