High throughoutput nep measurement

摘要

Apparatus and methods for measuring the quantity and size distribution of nep-like entities in a fiber sample are disclosed. An individualizer presents entities, such as fibers and neps, to a laterally elongated acceleration/deceleration gas flow nozzle having a laterally-extending sensing volume defined within the nozzle perpendicular to gas flow through the nozzle. The sample feed rate is such that multiple individualized entities are simultaneously presented to the sensing volume. A sensor output device produces a signal indicating the total amount of material within the sensing volume at any given point in time, such that the sensor output signal has a background resulting from fibers, and occasional signal pulses representing neps. An analyzer samples the signal at a sampling rate at least approximating the transit time of a nep-like entity through the sensing volume, and employs pre-sample and post-sample averaging background suppression to recognize a signal amplitude indicative of a nep-like entity. <IMAGE>