How Do Microwaves Behave; Reflection; Interpenetration; Absorbtion - Electrolux In General Service Manual

Fundamentals...

How do microwaves behave

The microwaves for the heating of meals behave like the electromagnetic waves which one
knows by e.g. broadcast and television. The frequency of 2,450 MHz means that the radiated
energy is oscillating 2,450,000,000 times a second.
The graphic below shows how microwaves behave in connection with substances, in this
case different dishes.

Reflection

Microwaves are reflected by metal. This is also used in the oven cavity to spread the waves.
However, the meals wood be shielded from the microwaves when using metal pots. It may
lead to sparks or, when the waves have a retrospective effect on the magnetron, to a
damaging of its anode.
Therefore, never use an empty microwave oven!!!

Interpenetration

Many materials let microwaves pass through without that they react themselves (glass,
porcelain, pottery, plastic (suitable for microwaves!) and paper/board (dry)).
This is used during the microwave operation. The waves can penetrate into the food
without loss.

Absorbtion

Liquids and nearly all organic food absorb microwaves and convert their energy into
heat (cooking): Depending on the liquid contents of the food, this heating behaviour is
different, too.
CLOSED CONTAINERS SUCH AS BOTTLES,
SCREW CAP GLASSES AND EVEN EGGS (SHELL!)
DO NOT BELONG IN THE MICROWAVE OVEN.
created by TSE-N, Reiner Kurzke
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