A helix strip bimetallic thermometer is wound spirally to achieve what?

A helix strip bimetallic thermometer employs a spirally wound structure to amplify the motion of the pointer. The design utilizes two different metals with distinct expansion rates when heated. As the temperature changes, the different metals expand at different rates, which causes the helix to unwind or wind more tightly. This movement is translated into a larger movement of the pointer on the thermometer's scale.

By using a helical configuration, the mechanical advantage is increased, allowing even slight temperature changes to result in more pronounced movements of the pointer. This amplification is essential for enhancing the sensitivity of the thermometer, allowing for greater accuracy and precision in temperature readings.