* Technology is the application of scientific knowledge for practical purposes. Thermometers use the principles of thermal expansion (liquids or metals) or electrical resistance changes to measure temperature. This is scientific knowledge applied for a practical purpose - determining the temperature of something.

* Technology involves tools and instruments. A thermometer is a tool specifically designed to measure temperature.

* Technology can evolve over time. Thermometers have evolved from simple, rudimentary devices to advanced electronic sensors.

Therefore, a thermometer, as a tool that applies scientific knowledge to measure temperature, is considered technology.