During the last several years, numerous important product innovations occurred in cigarette- and filter-technology. Eventually, those developments resulted in products that called for appropriate technologies to optimize product quality control.

Microwave resonator technology had become a well-recognized and effective tool to analyze the various unique quality characteristics of the products spawned by those new developments. In particular, the tobacco industry is familiar with the ability of the microwave resonator technology to precisely determine tobacco moisture, weight and cut position of cigarettes independently of the tobacco-sort density (e.g. to prevent loose-end tobacco fall out). Such devices require pre-calibration, and their measurements are not affected by time, user, and location. Hence, they provide the advantage that they can readily be used for benchmarking against the same organization-wide standard (transferability of calibrations across devices derived from a single master calibration).

A new development is the use of microwave technology to verify and monitor the quality and characteristics of both filter rods and cigarettes that contain aromatic capsules or have multi-segmented filter tips, and of cigarette filter tips that contain either charcoal or mono-acetate segments. The position and the content of each capsule are now measureable, and cigarettes or filter rods with incorrect positions or incompletely filled capsules can thus be ejected.

The microwave resonator technology is now able to measure the edge-positions of the segments in multi-segment filters or cigarette filter-tips. In segments which contain carbon, the charcoal content and the distribution of the granules can now be measured as well, and cigarettes or filter rods with incorrect edge-positions or charcoal content can be ejected. In further developments, it is anticipated that foreign body detection and ejection of cigarettes will be possible. This application can likely be extended to in-line high speed quality checks for control for filter rod machines.