A device for counting anything.

colony counter

An apparatus for counting bacterial colonies in a culture plate.

Coulter counter

An automated device that counts cells (e.g., bacterial cells or blood cells of eukaryotic organisms) or subcellular particles. It works by detecting a change in the electrical conductance of a fluid as it drawn through a small aperture. Coulter is a registered trademark of Beckman Coulter, Inc.

impedance counter

A blood cell counter that uses cell membrane electrical impedance to determine the volume of cells in a solution.

particle counter

An electronic device for counting and differentiating cells, platelets, and small particles according to their volume.

scintillation counter

A device for detecting and counting radiation. Flashes of light are produced when radiation is detected.