GB-2
ENGLISH
HEATING
CATEGORY
Microwaves will pass through certain materials, such as glass and
plastic, to heat the food. (See 'Suitable Ovenware' on page GB-
16
).
Water, sugar and fat in food absorb microwaves which cause them to
vibrate. This creates heat by friction, in the same way your hands get
warm when you rub them together.
The outer areas of the food are heated by the microwave energy,
then the heat moves to the centre by conduction, as it does in con-
ventional cooking. It is important to turn, rearrange or stir food to
ensure even heating.
Once cooking is complete, the oven automatically stops producing
microwaves.
Standing time is necessary after cooking, as it enables the heat to
disperse equally throughout the food.
Microwaves are energy waves, similar to those used for TV and radio
signals.
Electrical energy is converted into microwave energy, which is
directed into the oven cavity via a waveguide. To prevent food and
grease entering the wave guide it is protected by the waveguide
cover.
Microwaves cannot pass through metal, because of this the oven
cavity is made of metal and there is a fi ne metal mesh on the door.
During cooking the microwaves bounce off the sides of the oven
cavity at random.
HOW
YOUR
OVEN
WORKS
The heating category (a letter A to E) developed by MAFF (Ministry of Agriculture,
Fisheries and Food) with microwave oven and food manufacturers indicates the
ability of the oven to heat small quantities of food (up to 500g [ I lb 2oz]). It does
not represent the general performance of the oven.
Food packs carry cooking instructions for heating categories A to E. Follow
instructions for the letter corresponding to the oven's heating category. The
higher the output power and heating category of the oven the less heating time is
required as shown opposite.
Microwave output power
in Watts (based on
international (IEC 60705)
standard).
Letter representing the
oven heating category.
Microwave Symbol.
OVEN
OUTPUT
POWER
Less heating time required
600 700 800 900 1000 Watts
More heating time required
OVEN
OUTPUT
CATEGORY
Less heating time required
A B C D E
More heating time required
Microwave Symbol.
Microwave output power
in Watts (based on
international (IEC 60705)
standard).
Letter representing the
oven heating category.