Abstract: Method and sensing module for sensing pollution of outside air. The sensing module (1) comprises an electro chemical sensing element (3), and a processor (2). A sensing module output signal is provided based on the measurement signal and a baseline signal level. The baseline signal level is adapted depending on two threshold levels (13-15). A pollution concentration value is determined from the measurement signal and a classification level of air pollution is provided as sensing module output signal. A classification level is determined using a plurality of classification threshold values and the pollution concentration values. The plurality of classification threshold values are dynamically adjustable.

Abstract: Yarn is conducted through a frame in a substantially fixed path and fluid, such as dye, is sprayed thereon. The spray nozzles include a plurality of nozzles extending downwardly from a supply tube and the tube is mounted for reciprocating movement. Another set of spray nozzles are mounted on a polygonal tube which is rotated about an axis substantially perpendicular to the yarn path. The yarn is then heated and spooled. Dye passing the yarn is collected and recirculated to the spray apparatus.