Service manual

PN 4237242C
7.2-3
TROUBLESHOOTING
GENERATING A SERVICE REPORT
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Ratio CV: The ratio of good pulses to total pulses is calculated for each of the 12 count
periods, then the CV of the 12 ratios is calculated.
Voteout: The 12 count periods are grouped into 3 sets of 4 count periods, each set being a
logical aperture. If one "aperture" count is too far removed from the other two, it is "voted
out" and its number is given. If there is no voteout or a total voteout, a zero is given. The
report prints the logical aperture that voted out.
Hgb Data
To help investigate Hgb problems, the Hgb data collected by the instrument during data
accumulation is provided in this section. This data, four readings in all, is the output of the
Hgb Preamp card expressed in mV.
The Hgb parameter is a calculated comparison between a light transmittance reading of the
sample referenced to a reading of clear diluent. Two readings are taken when the sample is in
the bath and two are taken when clear diluent is in the bath. The diluent reading is referred to
as the HGB Blank read, while the sample reading is referred to as the HGB read. Each reading
is actually a series of 50 readings subjected to software filtering and takes about 1 ms to
complete.
The HGB Blank #1 reading is taken on the sample prefill just before the aspirated sample is
introduced to the WBC bath. The HGB Blank # 2 reading is taken on the original rinse just
before the probe moves across to the aspirate position. The two Hgb readings are taken just
before the sample is drained from the WBC bath toward the end of the cycle. There is a
1/2 second delay between the Hgb readings.
Analysis of the Hgb reading results is shown in flowchart form in Figure 7.2-3.
Sample Results - DO NOT REPORT
Several considerations for an AIM determination are based on the parameter results. If any
single AIM criterion fails, the results are displayed with a single asterisk (*) following them. If
however, more than one AIM criterion fails, the results are suppressed and instead a string of
asterisks (*****) is displayed. Since an AIM Alert may suppress the actual results, you must
obtain the Service Report if you need actual results. The actual results are included on the
Service Report for diagnostic use only, and should not be reported.
Below is a listing of AIM criteria based on parameter results.
r For WBC, ignore CV Ratio if WBC < 2.5 x 10
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r RBC AIM if MCHC < 25 (ignore if Hgb incomplete)
r RBC AIM if MCHC > 40 (ignore if Hgb incomplete)
r RBC AIM if (Hgb x 3)/Hct < 0.8 (ignore if Hgb incomplete)
r RBC AIM if (Hgb x 3)/Hct > 1.2 (ignore if Hgb incomplete)
The instrument does not generate an AIM if:
r Hgb < 1.0 g
r If Hgb incomplete, RBC < 0.5 x 10
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r For WBC and RBC, a complete voteout occurs
r For WBC, WBC < 1.0 x 10
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