10 Hardware of Near-Infrared Spectroscopy
237
Fig. 10.2 Lean reflectance of beef (a) and its second derivative (b)
Fig. 10.3 Lean reflectance of beef with 20 µabs noise (a) and its second derivative (b)
The presence of noise affects the estimation of the ingredients, which depends
on the sample characteristics. The effects of noise on the ratio of performance to
deviation (RPD) [3] of three samples are shown on Fig. 10.4.
RPD of approximately 2.5 is obtained when the noise level is 20 mabs for the
sugar in a tomato, 500 µabs for the protein in polished rice, and 50 µabs for the
protein in unhulled rice. The required noise limits of the instrument are different
Fig. 10.4 RPD versus noise
corresponding to different
samples
237
Fig. 10.2 Lean reflectance of beef (a) and its second derivative (b)
Fig. 10.3 Lean reflectance of beef with 20 µabs noise (a) and its second derivative (b)
The presence of noise affects the estimation of the ingredients, which depends
on the sample characteristics. The effects of noise on the ratio of performance to
deviation (RPD) [3] of three samples are shown on Fig. 10.4.
RPD of approximately 2.5 is obtained when the noise level is 20 mabs for the
sugar in a tomato, 500 µabs for the protein in polished rice, and 50 µabs for the
protein in unhulled rice. The required noise limits of the instrument are different
Fig. 10.4 RPD versus noise
corresponding to different
samples