This spectral reflectance can be also measured using {HEAD ~ a spectrophotometer} or a spectral reflectometer, or may be measured using the densitometer for measuring {TAIL ~ the optical density} as a logarithm of the spectral reflectance 
This spectral reflectance can be also measured using { HEAD ~ a spectrophotometer } or a spectral reflectometer , or may be measured using the densitometer for measuring { TAIL ~ the optical density } as a logarithm of the spectral reflectance
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH