25
MICROWAVING PRINCIPLES
Microwave energy has been used in this country to cook and reheat food since early experiments with RADAR in World War ll.
Microwaves are present in the atmosphere all the time, both naturally and manmade sources.
Manmade sources include radar, radio, television, telecommunication links and car phones.
CONVERSION CHARTS
In a microwave oven, electricity
is converted into microwave by
the MAGNETRON.
REFLECTION
TRANSMISSION
Then they pass through the cooking
containers to be absorbed by the
water molecules in the food, all foods
contain water to a more or lesser
extent.
ABSORPTION
The microwaves cause the water molecules to vibrate which
causes FRICTION, i.e. HEAT. This heat then cooks the food.
Microwaves are also attracted to fat and sugar particles, and
foods high in these will cook more quickly. Microwaves can only
penetrate to a depth of 1
1
/
2
- 2 inches(4-5cm) and as heat
spreads through the food by conduction, just as in a traditional
oven, the food cooks from the outside inwards.
WEIGHT MEASURES
15 g
1
/
2
oz.
25 g
1 oz.
50 g
2 oz.
100 g
4 oz.
175 g
6 oz.
225 g
8 oz.
450 g
1 lb.
HOW MICROWAVES COOK FOOD
▲
▲
▲
VOLUME MEASURES
30 ml
1 fl.oz.
100 ml
3 fl.oz.
150 ml
5 fl.oz. (1/4 pt)
300 ml
10 fl.oz. (1/2 pt)
600 ml
20 fl.oz. (1pt)
SPOON MEASURES
1.25 ml
1/4 tsp
2.5 ml
1/2 tsp
5 ml
1 tsp
15 ml
1 tbsp
FLUID MEASUREMENTS
1 Cup
= 8 fl.oz.
= 240 ml
1 Pint
= 16 fl.oz. (UK 20 fl.oz.)
= 480 ml (UK 560 ml)
1 Quart
= 32 fl.oz. (UK 40 fl.oz.)
= 960 ml (UK 1120 ml)
1 Gallon
= 128 fl.oz. (UK 160 fl.oz.)
= 3840 ml (UK 4500 ml)
The microwaves bounce
off the metal walls and
the metal door screen.
