Type 23 cells are identical to Standard Rectangular fluorometer cells as listed on page 26 except that instead of having an open rectangular hole at the top, a block is fused to the top of the cell with a ground hole to receive a PTFE stopper. This provides a more suitable seal for volatile liquids. A PTFE stopper is supplied with each cell. Two stoppers are supplied with cells which have a path length of 40mm or greater.

Smaller volume Types 29F and 28F are identical to Types 9F Semi­Micro and Type 18F Micro cell ranges except they have a stopper instead of a lid. A PTFE stopper is supplied with each cell.

Sub­Micro cells, Type 16F, while retaining the exterior dimensions of a standard cell, are designed for the measurement of very small samples with volumes ranging from 10μl to 160μl. The fluorometer Sub­Micro cells have a third window at 90° to the incident light to allow emis­sion energy to be measured. Special adaptors are not required for this cell.

Type 583­F range of fluorometer flow cells is designed to fit most standard fluorometers. The inlet/outlet tubes are connected with a threaded M6 connector with PTFE tubing attached. A pair of M6 connectors is sup­ plied with the type 583 cell. The cells have three clear windows. The excitation beam passes through the cell, which also allows the cell to be used for absorption spectroscopy as well. The emission window is at 90 degrees to the excitation windows.

The 6BF reference materials are not standards with absolute values, but a set of six relatively stable fluorescent materials in a polymethyl-methacrylate matrix with which the stability of the instrument can be monitored. Four blocks exhibit broad band spectra which cover the normally used UV and visible region of the spectrum. Two blocks contain materials suitable for illustrating the selectivity of the technique as well as checking instrument resolution and wavelength calibration.