The high degree of accuracy maintained during production ensures a standard path length tolerance of +/- 0.01mm. The tolerance maintained for parallelism of the windows is better than 3 minutes of arc, therefore Quartz cells vary little in transmission values. Slight differences in the transmission of new Glass cells are due to variations in raw material transmission characteristics.

The transmission of matched cells is measured and each cell is given a match code. These codes are only of real value when comparing new cells because the transmission characteristics may change as surface contamination or deterioration due to handling takes place. Thus a new cell of a particular match code will not necessarily match an older cell of the same match code.

Although cells which are commonly used, such as the standard rectangular type, especially in quartz materials, can usually be supplied from stock in unlimited quantities of the same match code, cells would normally be supplied in matched sets of two or four, or in the case of Tablet Dissolution cells, matched sets of six, seven or eight.