WE HAVE come to use the word fried to describe any food cooked in a low-sided frying pan. Unfortunately that is incorrect and confusing. Food cooked in a pan with a small amount of butter and/or oil is sauteed. Food that is fried must be floating in deep fat, the temperature of which is held within a precise range.

In recent years, health-conscious cooks have avoided deep-fried foods, describing them as an assortment of grease-filled, soggy and fattening substances with a toxicity level somewhere between unfiltered cigarettes and rattlesnakes venom. It is a sad description, but too often accurate for many of the deep-fried foods currently served in restaurants and fast food establishments.

Deep-fat frying, done properly in utensils designed for that purpose, results in crisp, greaseless food that is delicious and digestible. It is one of the simplest cooking techniques and requires only three pieces of equipment: a pan, a basket and a thermometer.

The oil in which food is deep-fried should be at least three inches deep in order to reduce the risk of spattering and insure that every piece of food will be surrounded by the cooking fat. Above the hot fat, you will want at least two inches of pan to guard against spatter while the food is cooking. Therefore, the deep-fat fryier pan must have a depth of at least five inches. The sides of the pan should have a slight flair as they rise from the base. As the food is heated it will expand and rise to the surface and the flair will give the pan some additional cooking surface at the top of the oil.

Food that is deep-frying must never be crowded, so choose a pan large enough and don't put in more food than the surface will hold in one layer with space between each object. The pan should have a basket for lowering and raising the food in and out of the oil. It is possible to do this with a large wire skimmer, but quality deep frying pans are made with their own wire baskets that sit atop the oil on little hooks. This allows a basket of food to be easily drained above the oil after it has been cooked.

The best-of-class deep fryer is a restaurant quality product (manufactured in France by Balon and other companies) that consists of a large sauce pan of sheet steel. It has a matching basket of steel wire that is of excellent construction and design. A piece of metal rises from the lips of the pan and has a hook-like device at the top which holds the basket in place in the oil. This pan comes in two sizes -- 3 1/2-quart and 5-quart and has retail prices of $19 and $22 respectively.

With this pan a deep fat thermometer should be used. The secret of deep fat frying lies in maintaining the oil at the proper temperature. If the oil is overheated it "breaks" and deteriorates. A bad smelling and unwholesome substance called acrolein if formed at the high temperature point and the oil loses its ability to seize the food and give it a crisp outer layer. Soggy fat-filled food results from placing the ingredients in oil that is either above or below the proper temperature range for the recipe.

Deep-frying thermometers are made with two types of measuring systems. One type utilizes a column of mercury in a glass tube to indicate the temperature. The second is called a bi-term thermometer and registers the temperature according to the expansion of two different metals exposed to the same heat. I have seen mercury thermometers explode from the heat contained in deep frying oil and therefore always recommend bi-therm metal thermometers for home use. The key temperature range is from 350 to 400 degrees and it must be clear and fully legible. The unit should also contain a clip for holding the thermometer to the side of the pan during the frying.

The oil must be brought to the proper temperature before the first batch of food is put in, but it is equally important to allow it to reheat to that temperature before the second batch goes in. The temperature must be monitored during the entire process so make sure the thermometer fits comfortably and securely to the pan.

There are a few electric deep fryers made for home use. The SEB Companyof France makes a thermostatically controlled model that takes the worry out of temperature watching. It is made of stainless steel with good quality, heat-resistant plastic lids and handles. It is 10 inches in diameter and 7 1/2 inches deep. A tinned-wire basket holds the food above the hot oil bath that is maintained at a constant temperature. The lid must be kept closed during the cooking process so there is no spattering and virtually no "frying smell." A charcoal filter in the lid traps the oil droplets from the vapor and converts them to steam.

The basket is raised and lowered by a crank handle that is outside the fryer. The food goes in, the top is closed and the basket is lowered into the oil. There is very little danger of burns. At the end of the cooking time, the basket is raised and the top opened. It's called a Super Fry and retails fr $99.95 or thereabouts.

The Sunbeam Crocker Cooker-/Fryer which retails for $59.95 has most of the important SEB features and is widely available.