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.

HOW MICROWAVES COOK FOOD

Microwave oven is a Group 2 ISM equipment in which radio frequency energy is intentionally generated and used in the form of electromagnetic radiation for the treatment of material. This oven is a Class B equipment suitable for use in domestic establishments and in establishments directly connected to a low voltage power supply network which supplies buildings used for domestic purposes.

Oven Cavity

Magnetron In a microwave oven,

 

 

 

 

electricity is converted

 

 

 

 

 

 

 

 

into microwave by the

 

 

 

 

MAGNETRON.

Turntable

Waveguide

 

 

 

 

REFLECTION

The microwaves bounce off the metal walls and the metal door screen.

CONVERSION CHARTS

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

Microwave

Water Molecule Absorption

Vibration

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 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.

 

 

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)

19

Page 20
Image 20
Smeg Microwave Oven, SA384X manual Microwaving Principles, HOW Microwaves Cook Food