12MICROWAVING PRINCIPLESMicrowave energy has been used in this country to cook and reheat food since early experiments with RADAR inWorld 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.Microwave oven is a Group 2 ISM equipment in which radio frequency energy is intentionally generated and used inthe form of electromagnetic radiation for the treatment of material. This oven is a Class B equipment suitable for use indomestic establishments and in establishments directly connected to a low voltage power supply network whichsupplies buildings used for domestic purposes.CONVERSION CHARTSIn a microwave oven,electricity is converted intomicrowave by theMAGNETRON.REFLECTIONThe microwaves bounce offthe metal walls and themetal door screen.TRANSMISSIONThen they pass through thecooking containers to beabsorbed by the watermolecules in the food, allfoods contain water to amore or lesser extent.ABSORPTIONThe microwaves cause the water molecules to vibratewhich causes FRICTION, i.e. HEAT. This heat thencooks the food. Microwaves are also attracted to fat andsugar particles, and foods high in these will cook morequickly. Microwaves can only penetrate to a depth of4-5cm and as heat spreads through the food byconduction, just as in a traditional oven, the food cooksfrom the outside inwards.WEIGHT MEASURES15 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 MEASURES30 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 MEASURES1.25 ml 1/4 tsp2.5 ml 1/2 tsp5 ml 1 tsp15 ml 1 tbspFLUID MEASUREMENTS1 Cup = 8 fl.oz. = 240 ml1 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)