Medonic CA530, User Manual

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Measuring Principles
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3.12 LPCR (Large Platelets)
The LPCR (Large Platelets Concentration Ratio) parameter is calculated from the
PLT distribution curve. Platelets that are larger than 12 fl up to the (floating) dis-
criminator are expressed in % of the total PLT count.
The LPCR parameter is only valid if the MPV value is not zero.
3.13 PCT (Packed Platelet Volume)
The PCT is calculated as being PCT= PLT x MPV and expressed in %.
3.14 HGB (Hemoglobin Concentration)
The hemoglobin is determined from the same dilution as the WBC. For each
sample a blank is measured as a reference, this means that any drift in reagent-
and cuvette-absorption or lamp is eliminated. The photometer system consists of
a tungsten lamp, a cuvette with a length of 15 mm and a filter at a wavelength of
535nm (bandwidth 20nm). The HGB readings are slightly corrected for turbidity
in case of extreme WBC counts. The lamp is switched off if the instrument is in
stand-by-mode, giving it an extended lifetime.
3.15 MCH (Mean Cell Hemoglobin)
The MCH is a calculated value and is defined as HGB/RBC giving the mean
HGB concentration in each red cell.
3.16 MCHC (Mean Cell Hemoglobin
Concentration)
The MCHC is a calculated value and is defined as HGB/HCT.
The MCHC is calculated from 3 measured parameters and therefore an excellent
instrument stability check. MCHC=HGB/HCT HGB/(MCVxRBC).
In general it could be stated that if a daily mean value is found outside the range
32-35 g/dl, the instrument might have been wrongly calibrated. The daily mean
value of the MCHC parameter should be 33.5 +/- 1.5 g/dl.