MP Filtri LPA3, Operator'S Manual

Page: 31 / 48

PRODUCT OPERATION
Figure 5.16
NAS1638 alarm levels
NAS1638 can be used by selecting this as the test Format. The headings and boxes for the available settings change appropri-
ately. NAS1638 represents the overall cleanliness level as a single code, this being the highest of the individual codes generated
for each defined particle size. Hence, we have the option of setting a limit on this overall contamination class (the Basic Class), or
we can set individual limits on any combination of the classes for the defined particle size ranges (fig. 5.16).
AS4059E table 2 / AS4059F table 2 alarm levels
AS4059E Table 2 uses letters instead of numbers to indicate the particle size range, so the settings are labelled appropriately.
The standard specifies ways to represent a cleanliness level using only a subset of the available particle sizes, for example B-F.
The user can achieve this by only entering settings for the sizes desired, leaving the others empty. So, a limit of AS4059 7B-F
could be represented simply by entering a value of 7 for B, C, D, E and F.
AS4059F Table 2 is identical except the letters have been replaced by the numerical particle size values (fig. 5.17).
Figure 5.17
Automatic Particle Counters
29