Ruler
A metre rule has sensitivity or accuracy accuracy of 1mm.
Precaution to be taken when using ruler
- Make sure that the object is in contact with the ruler.
- Avoid parallax error.
- Avoid zero error and end error.
Thermometer
There are 2 types of mercury thermometer
- Thermometers of range -10oC – 110oC with accuracy 1oC.
- Thermometers of range 0oC – 360oC with accuracy 2oC.
Precaution to be taken when using a thermometer
- Make sure that the temperature measured does not exceed the measuring range.
- When measuring the temperature of a liquid
- immerse the bulb fully in the liquid
- stir the liquid so that the temperature in the liquid is uniform
- do not stir the liquid vigorously to avoid breaking the thermometer
Stopwatch
There are 2 types of stopwatches
- analogue stopwatches of sensitivity 0.1s or 0.2s
- digital stopwatches of sensitivity 0.01s.
The sensitivity of a stopwatch depends on the reaction time of the user.