A cook must check the internal temperature of a quarter-inch hamburger patty on the grill. Which device gives a trustworthy reading?

解析

A thermocouple or thermistor with a thin probe senses temperature at the tip, so it reads accurately in thin food such as a patty or a fish fillet. A bimetallic stem senses along a two- to three-inch sensing area, an infrared gun reads only the surface, and a cooler thermometer measures ambient air.