Study of the influence of NIRS acquisition parameters on the spectral repeatability for on-line measurement of crop straw fuel properties

On-line measurement of crop straw fuel properties is important for its effective utilization. Realizing on-line measurement using near infrared spectroscopy (NIRS) is potential but challenging. The influence of NIRS on-line acquisition parameters such as focal distance, speed of the belt, integration time on the spectral repeatability was studied using two different spectrometers. The spectral repeatability was evaluated by root mean square (RMS) value. The results showed that integration time influenced spectral repeatability significantly for both of the spectrometers. The spectral repeatability increased following the increase of integration time. However, the influence on the spectral repeatability of focal distance and speed of the belt were different for the two different spectrometers. Focal distance and speed of the belt had a significant influence on the spectral repeatability only for spectrometer A. The spectral repeatability decreased following the increase of focal distance or speed of the belt.