the operation principle of the bomb calorimeter

With the increasing concerns to health, the calorie content of the meal has become an important factor affecting customer’s decision in restaurants. The calorie content of food is usually measured using the bomb calorimeter. Please write a short essay (nor more than a page, Times New Roman, 12 point, single space,) about the operation principle of the bomb calorimeter, its operation procedure, and list the calories of at least three meals sold in a fast food chain restaurant such as McDonalds, Burger King, Subway, or others. You may use picture, figure, and table in your answers.