US Patent 7451722 Internal temperature measuring device

An inexpensive reusable device for measuring the temperature distribution in a substrate, such as meat, poultry, or fish, is disclosed. The device is easy to read, fast and convenient and low in cost without the use of batteries. The device, which utilizes thermochromic materials mounted on one or more metal carriers, can be inserted into or placed in contact with the substrate for determining the temperature gradient across the substrate.