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December 30, 2011 01:45AM
Welcome to a forum in which to discuss revisions to OP1.002-2009!

OP1.002-2009+ v5.03.006 serves as the starting point for this discussion. The plus-sign in the name for the document means that it proposed as a replacement for OP1.002-2009, which is the currently published version of our Standard; the number following the “v” is the version number for the draft.

Back in August 2011, version 4.01 was discussed during a TF2 conference call. Several errors and oversights in the currently published version of OP1.002 were exposed in that draft.

Version 5.03.006 incorporates some of the thoughts and suggestions that came out of the discussion in August. It also incorporates some comments emailed to me after individuals reviewed v4.01 and v5.02, which were both posted on OEOSC’s website.

The version 4 draft retains the current look and feel of OP1.002, which was modeled closely upon MIL-PRF-13830B in both its language and structure. I don’t think it is worth this committee’s time and effort to merely reproduce the old documents.

Version 5 departs dramatically from the old documents. It retains all of the old intent and content, but it features a more rational structure and clearer explanations. Version 5.03.006 represents a big change and improvement over 5.02.

All the relevant documents to participate in this forum are located at www.triptar.com/OP1002docs. Access to these documents is controlled and only open to members of OEOSC and ASCOP. The login credentials are the same as those for ASCOP standards documents on OEOSC's website.

Here is the list of the relevant documents that you will find at www.triptar.com/OP1002docs:

Draft versions of OP1.002-2009+
    OP1.002-2009+ v4.01.pdf
    OP1.002-2009+ v5.03.006.pdf

Discussion Guides:
    OP1.002-2009+ v05-03-006 discussion guide.pdf
    OP1.002-2009+ design guide ver01-03.pdf
    ANSI Style Guide 2003.pdf
Currently published version of OP1.002-2009:
Relevant MIL specs:
To join this forum, register your user name (first name + last initial) and a password. You should have instant access to the forum.

Contact me directly with any private questions or comments.

Allen Krisiloff

Edited 12 time(s). Last edit at 01/05/2012 04:29AM by AllenK.
Huge improvements!
January 15, 2012 02:51PM
I've got to say you have done a superb job on this draft, Allen. The time and energy that must have gone into this is to be commended.

What is the best way to provide you feedback? Should I redline the document for discussion at PW, or scan it in and send it to you?
Comments about the Design Guide
January 17, 2012 02:08AM
Allen, your rationale for this revision as explained in the Discussion Guide and Design Guide is articulate and compelling. Good job! I have given you offline input on the typos, etc. in the Design Guide. Next I will share a few thoughts and suggestions on the Design Guide before moving to the standard itself.
Page 3, second paragraph from the bottom: I don't think the concern originates from a worry about change in general but from a concern that earlier drafts did not seem like an improvement and from concern that if we stray too far from what the government and the industry is used to the revision would not get adopted, would not be accepted.
Page 5: QC Dept.: I think "unexpected" is a better choice of words than "surprising."
Page 10, Critique of MIL-PRF-13830B: I am embarassed to admit that this is the first time I noticed that the scope of MIL-PRF-13830B says it includes mirrors. And that its Table I includes scratch numbers of 30 and 15. And that defects on mirrors appear the same as defects on transmissive optics and are to be treated the same.
Page 10, third paragraph of Critique: I suggest "individual optical components" rather than "loose optical componenets."
Page 11, line 1, last word: I suggest "artifacts" rather than "defects" arising out of single-point diamond turning or precision molding processes.
Page 12, Dimensional Scratch Width Table, second paragraph: the "Disregard" column addresses the "scratches down to atomic sizes" concern.
Page 13, Terminology for "allowable": I disagree with the first sentence and find the rest of the section to be fuzzy.
Page 13, Otherwise Specified: Second paragraph, where does this "override" occur in OP1.002?
Page 14, paragraph 2: I don't think anyone said it was necessary to change decades of calculations; thus this is a specious argument. However, you are winning me over.
Page 14, Terms and Definitions (Glossary): good idea to move them to the back. MIL-PRF-13830B does the same thing.

Edited 1 time(s). Last edit at 01/17/2012 02:09AM by gordonb.
Comments on OP1.002 WD version 05-03-006
January 18, 2012 02:40AM
We should only have one foreword (not forward); the foreword to the Third Edition. It should summarize in two brief paragraphs what the forewords to the first and second editions said, then discuss the objectives and goals of the third edition. In the Dimensional Tolerancing Scheme, the magnitude does not refer to a scratch’s “maximum dimension,” it refers to its maximum width. A scratch’s maximum dimension would be its length. I suggest the second clause read “then the visibility tolerancing scheme shall be used to control digs, too. “Traditionally accomplished with a hyphenated pair of numbers” is not exactly accurate. MIL-C-48497 was dated 27 June 1974, and MIL-C-48497A superseded it on 8 September 1980. (I have not yet gone back to check if the first edition included letter grades.) MIL-F-48616 was dated 29 July 1977. the syntax of the last paragraph is not good. I don’t think it is correct to say that it is an unfortunate coincidence that the dig numbers are derived from the diameter of master dig artifacts. The Army drawing shows the digs are circles, complete with tolerances on their diameters. I understand what you are trying to say, but we need to discuss how to say it. Same goes for the last paragraph in this subsection.

More to come....
Comments on OP1.002, WD Version 05-03-006
June 15, 2012 09:56PM
Since I will not be able to attend the Monterey meetings, I just want to reiterate the position I have voiced in the past, that it is important that we start "freezing" sections of the draft standard so that we don't keep rehashing the same territory endless times. I hope that recommendations to this effect will come out of the Monteey meeting. I realize in saying this that fundamental to the ANSI way of developing standards is successive review at various levels from TF all the way to public review. Our task force is small enough that we should be able to reach concensus and move this document up the chain. I wish I could have been more involved and a more timely contributor. Thie draft is very good - the task force is getting close!

Perhaps the solution is to limit future reviews to show-stopper comments only. From my perspective, the following are 3 critical issues:

1. My reading of the draft is that we are "binning" the scratch and dig specifications, so that each scratch or dig number essentially is a 1-sided tolerance limit? I.e., for a scratch that appears worse than a #40 but not as bad as the #60, it is classified as a #60, for both acceptance to the limit and for accumulation calculations.

Do we need the same "binning" decision for both the visibility method and the dimensional method? MIL-F-48616, for example, includes minimum-relevant scratch and dig values that do not appear in the lists of maximum-relevant values, and the use of interferometers, microscopes, etc seems to imply an accuracy for dimensional specification inconsistent with binning.

If binning is the decision, is the designer limited to the choices in tables 1-4? If yes, this would clear up many of the comments that have been made by earlier reviewers. Wording in the paragraphs of section 3.1.2 that mention specifications not appearing in the tables should then be eliminated, because they cannot happen. There has obviously been a lot of effort made to clarify this, but to me, it is still not explicit.

Having said all of this, I also want to remark that the companies I have worked for have binned consistently.

2. Section 6.3 prohibits area imperfections on coated surfaces. This is a tightening of requirements beyond the three MIL specs said to be the models for OP1.002. MIL-PRF-13830B, MIL-F-48616, and MIL-C-48497 all allow area imperfections on coated surfaces in limited circumstances. This tightening will impede acceptance of our document.

3. The inclusion of 4X magnification in the definition of "Unaided Eye" in 9.1.1 is inconsistent with my experience, both at the companies I worked for and every customer with whom the issue came up. Our experience is that 4X magnification causes significant improvements in visibilith and corresponding increases in rejection rates. The available comparison artifacts cannot be relied on the scale the same way as scratches on optical surfaces, and the result is worse correlation.

The following comments either cover lesser technical issues or are editorial in nature: replace "she" with "the engineer" if "classified according to the grade levels" measn that classification can be only the values found in the tables, then many issues disappear. Anything judged to be less visible than a #10, for example, becomes a #10. In the last paragraph, suggest adding to produce "they can be useful but are not required..." suggest adding to produce "Only relevant scratches in accordance with table 3 are graded...". Also, the second sentence in comment 21 at the bottom of the page would be a useful addition to this clause. "S" is in the legend but not used in the equation. It is not necessary to reference Test 2 in this paragraph. Any smaller grade scratches that violate or come close to violating Test 2 will fail the equation here sooner. What if the tolerance is "5"? I suggest indication this is limited to the clear aperture. I believe it requires a careful reading to understand what constitutes a tolerance grade (range from the previous tolerance grade, not the difference between the maximum and minimum relevant limits for the grade). An example might help (for grade C, any dig greated than 100 and not exceeding 200).

4.1 It would be useful to finally clarify that the 135 degree angle is measured as the angle containing the optical material and not one of the outside angles. I've lost track of how many times I have been asked which way to measure this by cusomers, suppliers, or our own inspectors.

4.3.2 After stoning, the resultant imperfection should meet either the chip spec or the dig spec (or both) depending on location.

4.4.4 and 4.4.5 add "(see also 4.2.1)".

7.2 to be consistent, add "when peering through the component".

8.1.6 To the end of the last sentence, add "when 3.1.3 specs apply".

9.1.1 Consistent with mu comments above, delete "or a simple microscope (magnifier or loupe) of 4x or less".

9.7.1 What does 2) mean?

9.7.6 "Chamfer" is a toleranced feature in 13830, 3.3.1, and in this draft in 4.1. Many companies avoid the term entirely because it is used inconsistently throughout the literature. I suggest staying consistent with 13830.

9.10.3 I disagree with this definition, and suggest it be the definition of "cement separation". "Feathering" is a special case, and tends to be very inflammatory. the illustration in our draft of cement separation is not an illustration of feathering, either.

9.11.2 I disagree with this definition of sleek. To me, sleeks are fundamentally narrow. I have seen a number of instances of wide (> .5mm) scratch-like imperfections on surfaces that have smooth profiles, especially on but not limited to plastic optics, and nobody would classify them as sleeks. This definition should be limited to very narrow imperfections.

9.12 I have seen cases where poor control has resulted in localized, scratch-like (or dig-like) coating blemishes where only some layers of a multilayer coating are missing. the result is typically a dramatic difference in color - a green "scratch" on a blue surface, or the like. These are consistently evaluated to the scratch and dig requirements for the coating. We have always classified these as a type of void. Also, the term "void" is a common term in the optics community, and really should be included in our document, possibly as an "also called" clause.

9.13.1 This definition of chip is too restrictive. Conchoidal shapes are only one type of chip and the wording seems to imply that chips are inherently conchoidal.

Annex C The first two paragraphs should be combined.
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