invar
/ˈɪnvɑr/
noun
- A nickel-iron alloy that has a very low coefficient of thermal expansion, used in precision instruments and clocks.
- Invar is essential for making precision parts that must stay the same size in different weather.
- The clock's pendulum was made of invar to keep accurate time despite temperature changes.
- Scientists use invar in surveying equipment to prevent measurement errors from heat.