Material of Instruments.
I. Measuring scales are often made of Invar steel.
II. Invar is an alloy of Iron and Nickel.
III. Invar has a very low coefficient of thermal expansion.
IV. Using Invar minimizes errors due to temperature fluctuations during measurement.
V. If a brass scale is used in summer, it expands, causing the measured reading to be less than the true value.
