13 3.2 Examples of instruments, old and modern
1Length
Instruments (from older to more modern)
- measuring tape, ruler, vernier caliper, micrometer
2Mass
Instruments (from older to more modern)
- steelyard balance, two-pan balance, single-pan balance, digital balance (the sensitive ones are used after calibration)
3Time
Instruments (from older to more modern)
- hourglass, pendulum clock, stopwatch, digital clock
A sensible choice of instrument is the first step to an accurate result: you would not use a metre tape to measure the thickness of a coin, nor a kitchen balance to weigh a gold ring (see sources of error, Lesson 7).