1. Length: Measured in meters (m).
2. Mass: Measured in kilograms (kg).
3. Time: Measured in seconds (s).
4. Temperature: Measured in Kelvin (K).
5. Electric Current: Measured in Ampere (A).
6. Amount of Substance: Measured in mole (mol).
7. Luminous Intensity: Measured in candela (cd).
Here are some fundamental devices for measuring these quantities:
1. Length:
* Rulers: Simple tools for measuring short lengths.
* Measuring tapes: Used for longer lengths.
* Vernier calipers: Precisely measure lengths up to a few centimeters.
* Micrometers: For extremely precise measurements of very small distances.
* Laser rangefinders: Used to measure distances over longer ranges.
2. Mass:
* Balances: Compare the unknown mass with a known mass (e.g., triple-beam balance, analytical balance).
* Scales: Measure the weight of an object, which is then converted to mass using the local acceleration due to gravity.
3. Time:
* Clocks: Measure intervals of time using various mechanisms (e.g., mechanical clocks, quartz clocks, atomic clocks).
* Stopwatches: Used for measuring short durations.
4. Temperature:
* Thermometers: Measure the temperature of a substance (e.g., mercury thermometers, digital thermometers).
* Thermocouples: Measure temperature using the voltage difference between two dissimilar metals.
5. Electric Current:
* Ammeters: Measure the flow of electrical current in a circuit.
6. Amount of Substance:
* Molar mass determination: Determining the mass of a mole of a substance through chemical analysis.
7. Luminous Intensity:
* Photometers: Measure the luminous intensity of a light source.
Important Note: There are many other specialized devices for measuring these quantities more precisely or under specific conditions. The devices listed above are just a few examples of fundamental tools used for basic measurements.
