Final answer:
A hemocytometer is the counting chamber used to enumerate blood cells in a diluted specimen, essential for accurate cell counting in hematological analyses.
Step-by-step explanation:
The counting chamber used to enumerate blood cells in a diluted specimen is known as a hemocytometer. This device is designed with a grid of squares to help in counting the cells accurately. A known volume of diluted blood is applied to the hemocytometer, and blood cells are counted under a microscope. Multiple squares are typically counted to get an average for a more reliable measurement. Other devices or chambers, like a Petroff-Hausser chamber or Coulter counter, are used for counting different types of cells or under different conditions. However, for manual counting of blood cells particularly, the hemocytometer remains a standard tool in hematological studies.