In use, a test sample of blood is contacted with {HEAD ~ the matrix} of {TAIL ~ said test device} and the light reflectance therefrom is measured as an indication of the quantitative amount of hemoglobin present in said sample 
In use , a test sample of blood is contacted with { HEAD ~ the matrix } of { TAIL ~ said test device } and the light reflectance therefrom is measured as an indication of the quantitative amount of hemoglobin present in said sample
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH