COULTER HmX Hematology Analyzer, Справочное руководство

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PN 4237523A 3-14
OPERATION PRINCIPLES
Hgb CONCENTRATION MEASUREMENT
Retic Parameters
The system makes three measurements as each cell passes through the flow-cell aperture:
r
The low-frequency, impedance measurement (which defines the cell's volume)
r
The high-frequency impedance measurement (which indicates the cell's internal
conductivity)
r
The light-scatter measurement (which indicates the cell's structure and shape).
Derived and Computed Parameters
From directly-measured parameters, the computer derives:
r
MCV and RDW from the RBC histogram
r
MPV and Plt count from the Plt histogram.
From derived and directly-measured parameters, the computer computes Hct, MCH, and
MCHC.
3.6 Hgb CONCENTRATION MEASUREMENT
After the WBC dilution is lysed, the system shines a beam of white light through the WBC
aperture bath and then through an optical filter. This transmittance of light (525 nm
wavelength) through a standard path length of Hgb solution is compared to the transmittance
of such light in the same way through a reagent blank. The system converts this ratio to
absorbance. It then converts absorbance to Hgb values in g/dL using a calibration factor.
3.7 PARAMETERS AND THEIR DERIVATION
Mathematical expressions in this section are in US units of measurement. You can change
parameter units to any of four International Systems of Units or the Japanese system by using
the Reporting Units screen. See the Heading, Reporting Units, in the Operator's Guide.
Figure 3.15 Scatterplot, DF 5 View Figure 3.16 Scatterplot, DF 6 View