Abstract: A method of color assessment of a sample (10) with respect to a reference illuminant, includes illuminating the sample (10) with a light source (12) that comprises a fluorescent lamp (18) and a plurality of light-emitting diodes (24). The spectrum of the LEDs (24) supplements the spectrum of the fluorescent lamp (18) to reduce deviations between the combined spectrum of the light source (12) and a target spectrum. The target spectrum may be that of the reference illuminant or it may be adjusted to make allowance for known properties of a color assessment cabinet (2) or an observing instrument (16). The LEDs (24) may be arranged so that their light passes through the bulb of the fluorescent lamp (18), which thereby acts as a diffuser. Alternatively, the LEDs (24) and the fluorescent lamp (18) may be located in a housing (31) from which their light can only reach the sample (10) after being mixed by reflection from multiple facets (34).

Abstract: A method of colour assessment of a sample (10) with respect to a reference illuminant, includes illuminating the sample (10) with a light source (12) that comprises a fluorescent lamp (18) and a plurality of light-emitting diodes (24). The spectrum of the LEDs (24) supplements the spectrum of the fluorescent lamp (18) to reduce deviations between the combined spectrum of the light source (12) and a target spectrum. The target spectrum may be that of the reference illuminant or it may be adjusted to make allowance for known properties of a colour assessment cabinet (2) or an observing instrument (16). The LEDs (24) may be arranged so that their light passes through the bulb of the fluorescent lamp (18), which thereby acts as a diffuser. Alternatively, the LEDs (24) and the fluorescent lamp (18) may be located in a housing (31) from which their light can only reach the sample (10) after being mixed by reflection from multiple facets (34).

Abstract: In a controlled stopping procedure for an open-end spinning machine the fibre feed roller and the yarn delivery rollers decelerate in synchronism. A detector senses a predetermined speed of the yarn delivery rollers after a period of time from starting the deceleration and initiates the stopping of the fibre feed roller. After a further period of time, determined by time delay means, the decelerating yarn delivery rollers are braked. Preferably the yarn delivery rollers have come almost to rest when they are braked.