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  • #3642921
    Stephen Seeber
    BPL Member

    @crashedagain

    Hanz: MVTR is for breathability (vapor transmission through the fabric).  Gurley is for air permeability.  The VISP MVTR will change with each different standard that is used to conduct the test.

    Eric:   Futurelight is more breathable than some Gore products.  Less than others.  If you are cold in your Event, put on a midlayer.  Problem solved.

    #3642928
    Hanz B
    BPL Member

    @tundra-thrasher-ouch-man-2

    Ah…. right

    #3642942
    Stephen Seeber
    BPL Member

    @crashedagain

    I produced regressions for the original 1947 data for .1″ and 1″ Gurleys.  Some of the original readings in the paper are illegible so the numbers I entered for a few may be incorrect.  The resulting R2 is .994 for .1″ and .993 for 1″.  I also used your regression equation to predict Frazier numbers for Gurley numbers of 25 to 1.  The Frazier predictions are good, within 10% up to 48.9 CFM/ft2.  At 5.7 the error is 27%. However, this may be the result of illegible numbers in the original data.  In short, your conversion does a reasonable job of going from Gurley to Frazier.  I am curious about how you did the regression.  In the 1947 paper, the authors had 2 Gurley machines and one Frazier machine.  The used each to test an array of samples and establish their regressions.  Were you able to do the same type test  with your Gurley and a Frazier?

    Now,the reason I am doing this is I am still trying to get to the bottom of the discrepancy between some of your prior air permeability readings and my present readings for the same samples and those of 3rd party labs that I hired to verify the test data.  As I have stated before, the 3rd party labs produced results in good agreement with mine.  The regression that you sent me does not account for the variance.  I would like to propose this:  I would like to send you a Patagonia L3a.  It is used but in excellent condition, with no evidence of wear.  You can measure the air permeability.  I will then pay to complete testing by a 3rd party lab.  We will then know how your measurement compares with those of my instrument and the 3rd party lab.  If there is a variance with your prior test results for this garment, then we can try to explain it.  Alternatively, if still have the L3a you tested, I can test it and send it to the 3rd party lab for testing.   I really did not want to rehash this issue on line but you don’t seem to want to communicate in PMs.

    #3643041
    Richard Nisley
    BPL Member

    @richard295

    Locale: San Francisco Bay Area

    Stephen,

    In a thread segment primarily addressing ShakeDry’s CFM, you requested that I retest the PCU L3A active insulator’s CFM that I first looked at 3 years ago… why in this thread?

    Per the ASTM D737, you need to address Table 2 definitions for the material to determine what the standard inter-lab allowable variance is for any valid comparison.

    a

    Stephen S.: What do you think ASTM D737 standard inter-lab allowable variance is for any valid comparison. These should always be the first step for fairness. This is a three-layer garment made up of two woven layers and a hydroentangle insulation making up the majority (59x) of the thickness?

    Roger C.: same question to you?

    Stephen – I don’t recall you ever publishing your CFM value for this garment; if you did, what is the URL.

    I have a Patagonia PCU L3A that I have tested a few times. The first time was three years ago and I have done two use degradation tests since then. My most recent test results were:

    For quick and dirty tests, the garment is just put in the tester without regard to air moving horizontally through the insulation versus only vertically. This value went from ~35F CFM when new to 34.05 CFM from three years of use (Alpha compaction).

    When the perimeter is tightly bound with a wide Velcro strap, the test values have averaged ~20.74 CFM; this is the value that should be compared with a Frazier. 99.9% of the CFM tests I typically do are membranes and fabrics. I have only tested two active insulation garments in the past 6 years.

    I have a removable garment section that I used for additional periodic element testing; those values are listed in the table above. I found it interesting that the outer EPIC material was significantly more breathable than the pedestrian nylon liner.

    Fluffing of the insulation was primarily for the companion insulation tests I did each time I checked the CFM.

    #3643042
    Roger Caffin
    BPL Member

    @rcaffin

    Locale: Wollemi & Kosciusko NPs, Europe

    I find the inter-lab precision (tolerance) to be rather large compared to the within-lab precision. This suggests that either the test is rather poorly defined so that everyone does it differently, or that typical fabrics vary greatly between rolls.

    That the 10-observation results are quite a bit better than the single-observation results does reinforce these concerns. The whole thing sounds a bit ‘fluffy’, as it were. But, some data is better than no data.

    The within-lab precision is not that much worse than the single-operator precision, which suggests to me that individual labs have reasonable control over their measurement processes.

    Cheers

    #3643100
    Stephen Seeber
    BPL Member

    @crashedagain

    Why this thread?  As near as I can tell, this thread revealed how you are doing your testing for Air Permeability. It was never clear to me that you were using a Gurley machine.  Of course, I am not critical of that.  There is some loss of accuracy inherent in the required conversion.  I have plotted the residuals from the 1947 data and the combination of the 1947 Frazier data and your regression equation and I understand the measurement errors.  They are probably in the ball park of measurements errors in my instrument compared with an actual Frazier machine.

    At this point, it is unclear how you test above 75 CFM/Ft2 and perhaps you can clarify this.

    I was cognizant of getting off thread with this discussion and asked to have an off line discussion, which, you evidently do not wish to pursue.

    There are two tests for which you have published results that are of particular interest to me.  One is the L3A and the other is the Bunn coffee filter.  The former, I believe was incorporated in your contention that 35 CFM/Ft2 is an optimal windshirt air permeability value.  The later was key to a do it yourself test that allows approximate  garment air permeability judgements.   My test results for the Bunn filter as well as the L3A are very different than yours.  Our results don’t agree well for other fabrics/garments as well.  These differences are larger than simple lab variation.  As you know, I had a lab test done of the Bunn filter and got results back that are similar to mine but very different than your published values. You indicated 70 for the filter.  I measure 29.3 and Touchstone Labs measured 26.9.   I have not published the L3A results nor had my results verified by a 3rd party lab.  I measure 9.35 for the entire structure and you measure 35. I think either will work and perhaps you think the Bunn filter would be simpler since it eliminates the test issues you raise.

    Our test results are sufficiently different that I think it is beyond Precision and Bias issues.  I don’t know where the difference originate with our measurements and perhaps we will find out.

    #3643110
    Richard Nisley
    BPL Member

    @richard295

    Locale: San Francisco Bay Area

    My L3A composite structure measured 20.74. This was explicitly stated in my most recent post. Our two values are well within the ASTM D737 standard for interlab testing this combination of materials.

    See my actual BPL forum post on coffee filter testing, for air permeability, at 2014 cofffee filters sold at my local store (no Bunn was ever tested)

    Regarding a variance in the average value for a collection of  coffee filters manufactured in 2013 versus one product manufactured today…. I am not wasting any more of my time explaining the absurdity of your preoccupation with this topic.

    Regarding the values above 75CFM, I use other machine sources for those values. 99% of my investingations are WPB membranes/coatings and fabrics below 75CFM. It is the same trade-off you made using a machine that can accurately measure high CFM values. but as Woubier pointed out, no scientific review has found it acceptable accurate for low CFM values.

    #3643170
    Stephen Seeber
    BPL Member

    @crashedagain

    Hi Richard:

    Here is a quote you may recognize:

    Of course this is from your paper “A Revised Paradigm for Understanding Garment Comfort Limits”

    This paragraph suggests to me that you measured a complete jacket to have permeability of 35 CFM.  It appears you then claim Patagonia built the garment to achieve 35 CFM.  I don’t believe Patagonia ever made such a claim.  The quotes you provide of Patagonia statements certainly don’t support such a claim.  However, you use your conclusion, in part to support your claim that 35 CFM/ft2 is somehow optimal.  Now, today, for the 1st time, you suggest that your real number is 20.74  Does that mean that you will change your recommendation of optimal to 20. 74?

    It is the same trade-off you made using a machine that can accurately measure high CFM values. but as Woubier pointed out, no scientific review has found it acceptable accurate for low CFM values.

    This is a pretty outrageous statement.  There is no definition of what constitute high or low CFM values in anything Woubier said and no citations of any specific studies.  So, where is one instrument superior to the other?  The Frazier machines is specified down to .15 CFM/Ft2.  The Gurley goes lower. So, I would say, if you want to measure below .15 CFM/Ft2, use Gurley.   Under what circumstances will an air permeability measurement below .15 CFM/Ft2 make any difference  in a garment?  Such a value is for all intents and purposes air impermeable and measures to even lower levels of impermeable will still be impermeable.  Gore may have a purpose in measuring such performance. Users of outdoor gear do not.  So if there is such a paper, cite it.  The 1947 paper provides no clarification. It says the following:

    Unfortunately, nowhere in the paper does it define what is meant by low porosity or high porosity.  I suspect this statement refers only to the limits of the conversion and not the accuracy of the instruments for their intended purposes.  For this paper, the limits of conversion are the limits of fabrics tested and they tested down to 2 CFM/Ft2.  This paper does not examine the accuracy of Frazier measurements.  It does not examine the accuracy Gurley measurements.  It simply attempts to measure the accuracy of the conversion equations that are developed.

    Your claims have impact on people’s actions.  For this reason, I think it is useful to review what is behind the claims.  Since you regard this as a waste of time,  there will be no review that we conduct cooperatively.     Rather, I will continue to use    3rd party lab testing as needed to demonstrate where your results cannot be duplicated.

     

     

     

    #3643175
    Sam Farrington
    BPL Member

    @scfhome

    Locale: Chocorua NH, USA

    Just when I thought I had it all figured out, you guys go ballistic on me.  Oh well …

    Will continue to use a Patagonia size LG M10 at 8.5 oz, and a Montane 3 oz pull over windshirt, the latter modified to add a netting kangaroo pouch.  They’ve both lasted well over 10 years and show no sign of wearing out.  So have never had to go through Dan’s disappointments.  Well, not than I can remember, anyway.  Do have some old rain jackets sitting around, but can’t even remember when or why I got them, or even why I keep them.

    We’ve seen so many of the combo rain/wind jackets on BPL, can’t remember those either.   Ah, the blessings of partial dementia.

    Was taking the sheep dogs for a walk one day in the headwaters plain of Twin Lakes in CO, and found myself in the path of a trail race sponsored by GTX.  The leader of the band came upon me and said, “I AM GORETEX!,” which was repeated several times for emphasis, and moved on with her brood.   The point being that many of us have viewpoints to which we are drawn, and can often provide us with pleasant pastimes, intellectual ones here on BPL.

    I like MYOG, because eventually the discussion stops, and I have to either make and put up a new piece of gear or shut up.  Granted, I’m a bit overdue, and do appreciate the helpful info exchanged on these forums.

    #3643570
    Weekend Gear Guide
    BPL Member

    @weekend-gear-guide

    Hello everyone,

    Here’s a picture of Scott Mellin, Global GM of Mountain Sports, The North Face, presenting a comparison between:

    – F2019 TNF Summit Series L5 Futurelight LT (FUTURELIGHT™ 3L) vs

    – S2018 OR Interstellar (Ascentshell™ 3L) vs

    – F2018 TNF Summit Series L5 Proprius (GORE-TEX® Active 3L)

    FUTURELIGHT vs Accentshell vs GORE-TEX

    https://www.snowsurf.com/media/__NEWS%C2%A02019/f%C3%A9vrier%202019/futurelight%20jan%20van%20leuwen/IMG_8738.jpg

    Stephen, Richard or anyone else; any ideas which testing methodology and equipment The North Face uses, to make these claims?

    Also, anyone have any thoughts as to why Gore, Outdoor Research or any other waterproof membrane manufacturer have not responded with any counter claim, given that there are many media outlets and websites now quoting TNF on their CFM and MVTR claims for Futurelight, and it’s been more than 1 year since TNF presented and gearjunkie etc. published these claims?

    #3643739
    Roger Caffin
    BPL Member

    @rcaffin

    Locale: Wollemi & Kosciusko NPs, Europe

    There are two possibilities.

    The first is that the TNF clams might be at least partly correct. Certainly, the CFM of any membrane product is so close to 0 as to not matter. The MVTR of membranes is not all that great either.

    The second is that the vast majority of the buying public never sees any of these videos and technical presentations and doesn’t care anyhow. They are far more concerned about appearance and marketing cool. Street Fashion.

    “Never mind the quality, feel the width.”

    Cheers

    #3643852
    Sam Farrington
    BPL Member

    @scfhome

    Locale: Chocorua NH, USA

    Obviously not being a techie, looked at a testing site that I’ve found to reliable for many years, and avoided the many that are new and unfamiliar.  There were only two reviews on REI, which were positive, but that level of response does not equate with a product that is a big step forward, as Futurelight is touted to be.  Scroll down for a helpful comparison chart of several products:

    https://www.outdoorgearlab.com/reviews/clothing-mens/hardshell-jacket/the-north-face-summit-l5-lt-futurelight

    Correction:  The 8.5 oz M10 mentioned in my previous post is a size XL, not a size L, and it will not be replaced by a Futurelight anything.

    #3644082
    Weekend Gear Guide
    BPL Member

    @weekend-gear-guide

    Thank you Sam for the link.

    It looks like OutdoorGearLab listed Futurelight’s qualities to be the Pros of this jacket and praised it’s performance and comfort:

    The North Face deserves praise for their new Futurelight fabric, but the comfort and breathability advantages of this material can not outweigh this jacket’s other design flaws. Our testers’ chief complaints were the ineffective hood and wrist cuffs that wouldn’t reliably stay closed. The Summit L5 LT is still a great jacket, but there are better choices currently available.

    But as you can see in their Cons and Conclusion, the overall design flaws of the Summit L5 jacket outweighed the advantages of Futurelight material used.

    So regardless of The North Face’s unbelievably high CFM and MVTR numbers, based on OutdoorGearLab’s real life review that gives critical low marks to the design and overall score, but at the same time notes how much more comfortable and breathable the Futurelight WPB fabric is, I think Futurelight does have a promising future for the consumer, if TNF can design a better functional jacket.

    #3644187
    Richard Nisley
    BPL Member

    @richard295

    Locale: San Francisco Bay Area

    Stephen,

    “How much easier it is to be critical than to be correct.” –Benjamin Disraeli…is an old saying that frequently comes to mind when reading posts from you.

    Your criticism, I suspect, is an attempt, in part, to delegitimize open-source testing by my myself and others. Your company Activewear-dynamics (https://activewear-dynamics.com/about-us) charges for these same types of tests and so you appear to attempt to delegitimize your perceived competition.

    The general scam as I see is: you copied the design of the Frazier air permeability tester used at Touchstone Labs. The results from the identical machines provide similar values. You then promote the zero-sum lie of “only Stephen’s machine is accurate”. There are three specific frauds supporting that claim.

    1)You lie about testing the same product that I did. The most recent example is you lied by saying I tested a Bunn coffee filter.

    2)You lie by admission by intentionally never specifying the ASTM D737 Table II material category and the standard’s inter-lab test acceptable variance for any valid test. Instead you ignore the standard and reference the machine you cloned value only.

    3)You lie by saying the patents and research papers don’t say what they actually say. So, the forum members can see your most recent lies first hand I will provide the links to each document and the page number that contains the information you said they didn’t say:

    Topic: Frazier not accurate for low CFM materials like WPB garments. Reference page 9 Here

    Frazier not accurate for low CFM materials like WPB garments. Reference page 16 Here

    Gore Laboratories will not use Frazier machines for material below 2 Gurley seconds which equals 30.5 Frazier CFM. Reference page 11 Here

    Gore Laboratories follows the guidance of the first three documents and no Gore air permeable patents are tested using a Frazier type machine. Reference their Shakedry patent for all pages referring to only Gurley testing. Here and Here

    The PCU L3A has had three test cycles by me. The last two correct reading can only be achieved by binding the jacket perimeter because the porosity of the center insulation is dramatically lower than either face fabric. That information was covered by me in an earlier post to this thread. A specific garment test has no bearing on determining an optimal CFM level for 7 MET activities. In my white paper you referenced, I provided the following chart which clearly showed that 35F only was best for 7 MET activities (average backpacking rate).

    a

    Windshirt suitability to a specific task is primarily determined by its ability to move moisture away from the user’s base layer and secondarily by protecting the user from external wind and moisture. I will include 4 regressions I did for different wind / walking speed CFM to moisture resistance measurements.

    As is the norm, you have contributed nothing but criticism to the analysis of an optimal windshirt CFM for backpacking.

    The relevant background information to understand these logarithmic regressions is that they include two “open” cases for use when hot. The windshirt’s hip adjustment is opened, both cuff adjustments are opened, and the neck is zipped down ¼ way to the point of a typical pack sternum strap. They also include two “closed cases” that would be used when cold and/or rainy. All the venting options mentioned above are closed.

    The most critical test is the windshirt’s ability to prevent base layer flash-off cooling when stopped after heavy exertion has caused perspiration. That is the one that appears to be optimal at 35CFM.

     

     

    #3644189
    Roger Caffin
    BPL Member

    @rcaffin

    Locale: Wollemi & Kosciusko NPs, Europe

    I do not wish to buy into these arguments right now.

    However, I would appreciate it if both Stephen and Richard were to update their profiles as they appear below their avatars in postings to include their commercial affiliations. Full disclosure please, in other words.

    Roger Caffin
    Moderator, BPL

    #3644190
    Richard Nisley
    BPL Member

    @richard295

    Locale: San Francisco Bay Area

    BPL wouldn’t allow the above graphs to be edited and so they are corrected and posted here. The first case is the primary one to make an optimal CFM recommendation for UL backpacking.

     

    #3644191
    Richard Nisley
    BPL Member

    @richard295

    Locale: San Francisco Bay Area

    Roger,

    I have no affiliation with any enterprise. I have never been compensated for my testing work in any manner. That includes non-cash reimbursement such as discounts, products, or favors of any type.

    #3644194
    Richard Nisley
    BPL Member

    @richard295

    Locale: San Francisco Bay Area

    Weekend,

    The TNF marketing test values are easy to achieve and the MVTR and CFM correlate (higly probable combination of values). The CFM value is most likely measured on a densometer and the MVTR is most likely using a JIS L 1099 Desiccant Inverted Cup (g/24hrs/m2) test.

    Vendors use the MVTR test because it provides big numbers and not because it provides and valid indication of how a garment will perform in the field.

    If you buy a garment like this to use for hiking or a day, walking the dog, for skiing a resort, it will work fine.

    It has a significant probability of endangering your life if you are on a long wilderness trip someplace like AK or WA state in the winter.

    It is an air permeable jacket with large pores combined with a DWR face fabric. In heavy sustained rain, the DWR will fail in a short periord of time. This will then cause three things to happen to the outside of the jacket. First the temperature will drop as much as 20F do to the latent heat of evaporation. Second, the pores will get filled with rain water. Third, the pores will stop passing water vapor. On the inside of the jacket, your persperation will condense on the cold surface; the MVTR will go to 0, and hypothermia will follow shortly.

    Ask yourself why TNF didn’t test this jacket in heavy rain and publish those results?

     

    #3644202
    Roger Caffin
    BPL Member

    @rcaffin

    Locale: Wollemi & Kosciusko NPs, Europe

    >> Ask yourself why TNF didn’t test this jacket in heavy rain and publish those results?
    Perhaps they did, so that should be
    Ask yourself why TNF didn’t test this jacket in heavy rain and publish those results?

    Cheers

    #3644225
    Stumphges
    BPL Member

    @stumphges

    Richard, I accidentally reported your post for inappropriate content by hitting “Report” rather than “Reply.” I apologize. Roger, would you mind fixing that?

    Richard, you’ve previously written that the issue you mention here with microporous membranes, of the pores eventually filling with water and no longer breathing, does not occur with woven windshirts. Why would that be? I would think that with woven fabrics the same would occur – once the DWR fails and the fabric saturates, the pores would also tend to fill with water.

     

    BTW, I object the tone many of the posts in this thread. I don’t find claims made here of “lies” to be credible. You guys disagree, fine. Your numbers don’t match? Why not? Figure it out, but please do so in a civil manner. What is it that they say about academics? ‘The fights are so bitter because the rewards are so small.’

    #3644239
    Jeff McWilliams
    BPL Member

    @jjmcwill

    Locale: Midwest

    Richard,

    Just to clarify: the effects you attribute to the TNF jacket in a sustained rain are going to happen to ANY microporous membrane jacket that depends on a DWR treater outer fabric layer to maintain breathability, correct?

    This goes back to the argument in favor of permanent beading surface jackets?

     

    #3644331
    Roger Caffin
    BPL Member

    @rcaffin

    Locale: Wollemi & Kosciusko NPs, Europe

    I agree 100% about keeping the discussion civil.

    Part of the problem here is that what is being measured is not all that well defined, so the number produced depends a bit on how the measurement was done. Richard and Stephen are each using different techniques.

    What does matter a lot more than who is ‘right’ are several other things:
    * an understanding of the rough differences between products (how one is ‘better’ than another);
    * an understanding of how and why different fabrics behave differently;
    * an understanding of why most marketing spin is total waffle and should be ignored
    * and finally, a realisation that there is no such thing as a perfect fabric or jacket (‘you are going to get wet’).

    </sermon>
    Cheers

    #3644345
    Sam Farrington
    BPL Member

    @scfhome

    Locale: Chocorua NH, USA

    Re:  “BTW, I object the tone many of the posts in this thread. I don’t find claims made here of “lies” to be credible. You guys disagree, fine. Your numbers don’t match? Why not? Figure it out, but please do so in a civil manner.”

    Hear, hear.

    #3644368
    Sam Farrington
    BPL Member

    @scfhome

    Locale: Chocorua NH, USA

    I agree with and accept contributors to BPL discussing matters in a scientific way that is also way above my head.  Nor should anyone feel restrained in any way from doing so.  Especially when this is a public forum, in a form where folks have plenty of time to grok the content.  (Well, the ads can be a little distracting – can you imagine them flashing away in an online college textbook?)

    I do use a different approach, however, having always worked in area of public service where it has been absolutely critical that people understand what I am saying; otherwise, the whole effort would be a total waste for everyone.  And that is definitely not how I want to spend my time or their time.

    Also, I think I get the point that is most relevant on threads like this one; namely that the discussion include some real connection with hikers’ experience.  Especially when there are lots of labs spewing out lots of different results.  I once began a long trek with a Goretex pull-over from LL Bean that I liked in every way.  However, after a few days of constant rain, it wetted out completely, and as Richard suggests, was worse than useless, because in endless cold rain, it could become life threatening.

    The problem is how to separate the wheat from the chaff amidst endless marketing claims.  And despite Roger’s hopes, one often does not know the affiliations of posters on BPL.  I would not be surprised if there is often a lot of covert marketing going on right before our eyes, that even includes, dare I say it, lies.

    But I accept this in a philosophical way, knowing that we live in a highly competitive economy.  And I accept that events these days can be highly stressful for many, which doesn’t help either.  So I’ve resolved to be as Buddha-like as possible, take enjoyment from the discussions where I can find it, and leave you all free to make your own choices.

    You may recall that I’ve posted on this and related threads that my rain gear has after many years evolved to become just peachy; but reading the experiences of others on this forum, can only conclude there is a plethora of junk on the market.  And I don’t get how putting a WPB membrane on the outside of a jacket can possibly be anything but a disaster for a trekker who goes out for weeks at a time, and often off-trail.  Nor do the claims of Futurelight make any logical sense to me whatever.  So I look for detailed experiences of other trekkers, and in this case, for a product that has been out for a while, find almost nothing.

    Weekender points to the laudable comments in the article I linked, but there is no beef there.  No details about weather, or length of treks, or the experience of testers.  And on the chart I mentioned, there are other products noted as more breathable and/or more waterproof.  That does not sound like a product making revolutionary advances.

     

    #3644372
    Stephen Seeber
    BPL Member

    @crashedagain

    Hear, Hear, indeed.  A way back in this thread, I though we might have a meeting of the minds and agree to a testing procedure to get to the bottom of our differences.  However, he concluded, it was not worth his time.

    Concerning his conspiracy theories:

    1) Claim:  I copied a Frazier machine I saw in a lab in South Carolina,etc. I have never actually seen a real Frazier machine, let alone copied one.  How he reached his conclusion on this subject is a total mystery to me.  I have explained many times how mine works.  It is basically a Shirley type tester.  The initial iteration borrowed heavily from a design from Lancem of BPL and then modified substantially to improve performance.  It includes 4 Dwyer rotameters.  I have recounted the calibration method I employed and the additional 3rd party testing I hired a number of times now.

    2) Claim: I have a commercial testing company and my views are therefore biased.  I have a website for garment testing.  I have never received any response from it.  So much for my commercial testing business.  My business strategy is a bit odd.  I have posted a number of articles that were critical of major garment manufacturer’s products.  I fear I have already burned my bridges before getting started.  I owned and operated a testing business for 36 years before I retired. People paid for their testing services without suggesting the results would be biased.  If a for profit entity wishes to hire me to test their product, I will do so but they will get my objective evaluation and nothing more, just like all of my clients throughout my career.  You will note I have never done anything to promote any commercial activities in anything I have contributed to BPL.  However, I thank Richard for bringing this to the public’s attention in case someone wishes to avail themselves of my services.

    3) Claim: I have never tested anything Richard has tested.  I suppose that is literally true.  I have tested many garments that Richard as tested.  However, never “THE” garment he tested.  However, he claims above that he never tested a Bunn coffee filter.  I refer to https://backpackinglight.com/forums/topic/86001/#post-2060105  where he describes his test of  Bunn and other filters.

    4) Claim: I lied about Frazier machine accuracy relative to Gurley.  He cites two papers to support his claim.  These are actually the same paper, published in two different places.  He used their data to produce his conversion curves.  Above, he claimed he did his own regression.  That may be true, just like I used the data in the papers to do my own regressions.  When I did, I get the same results that he and the paper authors got.  I will stand by my comments above on the subject.  I don’t see anything in those papers to support his claims about superior accuracy for one or the other.  The only exception is that Gurley can measure to minute levels that are not relevant to garment comfort.

    5) Claim: I lied about Gore’s use of the Gurley or Frazier machine.  He should reread my comments above. Gore’s use of Gurley or Frazier machines for their purposes, if used according to their manufacturer’s specifications, says nothing about the relative accuracy of the machines. Clearly, if you want to measure below .15 CFM/ft2, you will need to use a Gurley machine.

    In any event, I proposed a testing scheme, above, and I offered to pay for 3rd party testing.  He declined.  There may be no path forward with him to resolve the test discrepancies.  However, people should be aware of these discrepancies as they evaluate their purchasing decisions.

    Steve

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