How is the pressure of a carbon brush on a commutator measured?

The pressure of a carbon brush on a commutator is most accurately measured with a wire gauge. This tool allows for consistent and precise measurement of the brush pressure, ensuring that the contact between the brush and commutator is maintained at the optimal level for efficient operation. Proper pressure is crucial for effective current transmission and minimizing wear on both the brush and commutator surfaces.

Using a voltmeter is not applicable because this instrument measures voltage, not pressure. Measuring by hand introduces a level of subjectivity and potential for error, lacking the precision required for accurate assessments. A digital scale, while capable of measuring weight, would not provide the necessary context for brush pressure specifically in this application, as it doesn't account for the specific configuration and dynamics involved in the brush-commutator interaction.