Sector (instrument)

A sector (instrument) is a tool or device that's used to measure or do something. For example, a ruler is a type of sector (instrument) because it's used to measure. That means you can use a ruler to measure how long or how tall something is. Some other examples of sectors (instruments) are thermometers, which measure temperature, or a stethoscope, which measures heartbeat. So basically, a sector (instrument) is something that helps you measure or do something!