NEC MultiSync FP1370 Service Manual page 87

3. Limits
3-1. Scratch
Width(mm)
0.16 ～
0.11 ～ 0.15
0.06 ～ 0.10
～ 0.05
NOTE 1: Even though width of scratch is more than 0.16mm, regard scratch whose contrast is weak
extremely as stain and apply standard of 3.2.
NOTE 2: Do not recognize flaws which injures goods prices though it is not especially stipulated as for zone C.
3-2. Opaque flaws ( ex. Stain ) and coating peeling
Do not apply the following standard to zone C.
Classify flaws by contrast and judge it by size.
Definition of a contrast
High contrast
Middle contrast :A semitransparent foreign substance and stain
Low contrast
Standard
Average diameter classified by a contrast
NOTE 4 (mm)
High contrast Middle contrast Low contrast
～ 0.10
0.11 ～ 0.25
0.26 ～ 0.50
0.51 ～ 0.75
NOTE 1: A number inside brackets show allowable number of Low contrast. However, it is based on
the following tables as for the total number of a low contrastive fault.
NOTE 2: If a defect has different contrast's one in it, shall be judged by higher contrast's
specification.
NOTE 3: Allowable length between the different class is applied on size standard.
NOTE 4: Convert (a+b)/2 or a/20 + 2b small value into average diameter. (a: length, b: width)
total number of a low contrast flaws
Standard classified by zones
Total ( zone A + zone B )
Allowable Length(mm)(Zone A + Zone B)
:The foreign substance which shuts off light from fluorescence surface
(Ex. coating material which has been changed )
:stain and dust which do not reflect light from fluorescence surface and can be
distinguished by its appearance
～ 0.20 ～ 0.50
0.21 ～ 0.50 0.51 ～ 1.25
0.51 ～ 1.00 1.26 ～ 2.50
1.01 ～ 1.50 2.51 ～ 3.75
reject
13
26
unlimited
Allowable number
zone A
Rejected
2［4］
1［4］
0［4］
zone A
6
10
6-7
Allowable Length
(mm)
NOTE 3
zone B
Rejected -
4［5］
20
2［4］
40
1［4］
80
zone B
8