SPM A2010 - The COND Number; Relationship between Output Data

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Technical data are subject to change without notice.
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Fig. 17
Field A = Good condition
Field B = Condition reduced by
poor lubrication
Field C = Condition reduced by
poor surfaces
Field D = Damage
Fig. 18
The COND No. (condition number) is displayed with
CODE B, C, and D, i.e. for all bearings with reduced
or bad condition. It indicates the degree of surface
deterioration or damage in the rolling interface.
Large (visible) surface damage typically leads to a
very marked increase in the bearing's LR readings and
a high delta value (figure 17). Thus, it is easily de-
tected and will give Code D and high COND num-
bers.
When a COND number is displayed, the bearing should
be watched very carefully. Once damage has started,
it cannot be reversed. Temporary improvements of
the COND No. only mean that the edges of fresh
spallings or imprints have been rounded off. Soon,
there will be new spallings.
The time left to plan a bearing replacement depends
on the trend of the COND No. As a rule, COND Nos.
should be interpreted as follows:
COND No. < 30 Minor damage
COND No. 30 to 40 Increasing damage
COND No. > 40 Severe damage
Relationship Between Output Data
Figure 18 shows the relationship between CODE,
COND, LUB and the measured raw data, HR and LR.
HR is plotted horizontally. The delta value (= LR – HR)
is plotted along the vertical outer scale.
The fields marked A, B, C, D correspond to the condi-
tion codes. Together, they form the area in which the
A2010 expects to find the HR and delta values for a
given bearing. Size and shape of this area varies ac-
cording to bearing type and speed. Readings falling
outside of the area produce error codes.
The black circle marks a shock pulse reading. Here HR
is 12 (horizontal scale) and LR is 16, giving a delta
value of 4 (vertical scale).
This puts the bearing into field A (good condition),
and gives it LUB No. of 3 (inner scale, horizontal). The
COND No. (inner scale, vertical) is below 20 and not
displayed.
The COND Number