Sedgewick Rafter Counting Chambers are used in water analysis, culture inspection and applications where particles per unit volume must be ascertained. The Chamber consists of a 2mm thick clear base slide measuring 76 x 40mm. A rectangular chamber has been built onto this base. A coverglass is then placed atop the chamber.

The Chamber measures 50mm L x 20mm W x 1mm deep with a grid-marked base of 1000 1mm squares. When the chamber is filled with liquid and the coverglass in place, a 1 ml volume of liquid is trapped. Under low magnification with a light microscope, each grid square is equivalent to 1 microliter(ul) of liquid.

The S53 Sedgewick Rafter Counting Chamber is for many counting applications, APHA methods and where large particles and larger zooplankton in fluids are being analyzed. The S53 is plain glass without grid markings. The chamber holds 1 ml. of fluid. The S53 may be used with an eyepiece reticle where counting and sizing is required.

Sedgewick Rafter Chambers are available in an economical plastic version for education and training, a professional version with high quality optical glass with a chromium surface image with counting grid, and a high quality optical glass without grid markings for large particles. The coverglass is compatible with all chamber versions.

Note: Over the years the name of these slides has been incorrectly spelled as Sedgewick Rafter. The original methods were developed by William Thompson Sedgwick and George W. Rafter, so the true spelling should be Sedgwick Rafter.