What type of tape, made from nickel and steel, is less affected by thermal expansion than steel chains?

Invar tape is made from an alloy of nickel and steel that has a very low coefficient of thermal expansion. This means that it does not expand or contract significantly with changes in temperature, making it particularly advantageous for precise measurements in surveying and engineering applications. The stability of Invar tape under varying thermal conditions allows surveyors to obtain more accurate and reliable measurements compared to steel chains, which are more susceptible to thermal expansion and contraction.

In contrast, while other materials like copper, steel, and plastic tapes each have their own uses in surveying, they do not offer the same level of thermal stability as Invar tape. Steel chains, for instance, can experience noticeable changes in length due to temperature fluctuations, which can lead to measurement errors. Therefore, Invar tape's unique properties make it the preferred choice for scenarios where precision is critical.