Effect of Measurement Principle and Measuring Field on Uniformity Measures of Spun Yarns

The effect of measuring field length on yarn evenness is investigated by comparing the coefficient of variation or CV of the measure obtained from three different sensors with different measurement principles: a capacitance sensor with an 8 mm sensing zone, an optical sensor with a 2 mm sensing zone, and a laser scanner with a 1 mm effective sensing zone. A probabilistic model is developed to predict the different CV values obtained from the different instruments, and the results are compared with experimental values.