Appendix B
Messages
19
Message: Result Codes
This message is transmitted after each test.
The test result is expressed as a set of codes
in the selected Test Format (ISO4406,
NAS1638 etc)
. The test result message is always 8 bytes long, with the result codes
packed as follows:
Format:
ISO4406
AS4059E2
NAS1638/AS4059E1/ISO11218
VII
Byte
Code
Class
Class
1
4µm(c)
Basic
VIII
Basic
2
6µm(c)
-
-
3
14µm(c)
A
5-15µm
4
21µm(c)
IX
B
15-25µm
5
25µm(c)
C
25-50µm
6
38µm(c)
D
50-100µm
7
50µm(c)
E
>100µm
8
70µm(c)
F
-
Special Values
The result codes use a few ``special’’ values in order to represent codes that are not
simple numbers.
The NAS1638 standard defines classes ``00’’ and ``000’’, these are classes ``cleaner’’
than class 0. We represent these using signed integers of value -1 and -2 respec-
tively.
X
VII
NAS1638, AS4059E Table 1, and ISO11218 standards produce identical numerical codes so they are
listed together here.
VIII
The ``Basic’’ class is the highest of the individual size classes
IX
ISO4406 only defines codes for the first three sizes 4,6 and 14µm(c). We extend the concept to cover
the other sizes. This allows limits to be set on the number of large particles, even when using the ISO
4406 coding system.
X
These will appear as 255 and 254 if read as unsigned integers.
