Final answer:
Food thermometers must have an accuracy of ±2°F (±1°C) to ensure food safety. They use materials that expand or contract with temperature changes. Accurate temperature measurement is vital in health and food safety applications.
Step-by-step explanation:
Thermometers designed for measuring the temperature of food must be accurate within a degree of error of ±2°F (±1°C). This is critical for ensuring food safety and avoiding the risks associated with undercooking or spoilage. Accurate temperature measurements are essential in a range of applications, not only in kitchens but also in scientific and industrial settings.
Thermometers accomplish this by employing materials that expand or contract in response to temperature changes. For instance, mercury or alcohol in a thermometer expands when heated, which increases the length of the liquid column and indicates a rise in temperature. Conversely, when the temperature drops, the liquid contracts, and the liquid column shortens.
Having an accurate thermometer is crucial, especially when caring for the sick where a slight deviation could mean the difference between a normal and a dangerous body temperature. Whether it is measuring body temperature or ensuring that food is cooked or stored at safe temperatures, a reliable and precise thermometer is indispensable.