Register (counter) and dry-dial meter

The register is the part of a meter that shows the volume passed, on rollers, pointers or a digital display. In a dry-dial meter the register sits in a sealed chamber, kept apart from the water and usually driven by a magnetic coupling, so dirty water never reaches the dial.

A register clouded by silt, scale or condensation leads to misread bills and disputes. Dry-dial construction keeps dirty water off the dial; a good seal keeps moisture out.