Michigan Test for Teacher Certification (MTTC) Secondary Integrated Science Practice test

What air pressure measuring device uses a sensitive metal pointer?

1. Mercury Barometer

2. Differential Barometer

3. Aneroid Barometer

4. Barograph

The correct answer is: Aneroid Barometer

The aneroid barometer is recognized for using a sensitive metal pointer to measure air pressure. Unlike other barometers that may rely on liquid, such as mercury, the aneroid barometer utilizes a flexible metal box, called an aneroid cell, which expands or contracts with changes in air pressure. This movement of the cell is then translated onto a metal pointer on a dial that accurately reflects the atmospheric pressure. The design of the aneroid barometer allows for a more portable and less hazardous alternative for measuring pressure compared to the mercury barometer, which uses liquid mercury that can be dangerous if broken. While a barograph also records changes in air pressure, it typically utilizes more complex mechanisms involving ink and chart paper rather than a simple metal pointer. The differential barometer is not common in standard pressure measurement and employs a different technology altogether. Thus, the specific function of utilizing a sensitive metal pointer aligns with the characteristics of the aneroid barometer, making it the correct choice in this context.