This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.
Answering the question post #29 raises rather than the one it answers.
The bit of submitting a sample that nobody enjoys is that the answer changes depending on what you are trying to decide with it. Say what the decision is and the thread will converge.
Something worth flagging about submitting a sample: the strongest-sounding claims in this thread are the ones with no source attached, which is the usual pattern and not a coincidence.
Repeat determination on the same product line months apart is the measurement that speaks to consistency, and consistency is what most buyers actually want.
That is the honest state of it as of this week.
The record shows what was measured. Everything beyond that is inference and this site tries to keep the line visible.
The reasoning is more useful than the number, which is why I have shown it.
Offering a way to settle submitting a sample rather than another opinion about it. Two measurements, taken the same way, a fortnight apart. If the difference is within the noise, the question was not answerable at this precision.
If you are new and reading this thread for the answer to submitting a sample: the answer is conditional, the conditions are in the third reply, and the rest of the thread is worth skipping.
Repeat testing: if you want to verify the same lot a second time, testing with a different service strengthens the conclusion. Testing with the same service verifies reproducibility but uses the same method.
The disagreement above is smaller than it looks once the terms are fixed.
It does not extend to lots nobody has seen, it is not a recommendation, and it says nothing about anything other than what was measured.
Same experience here, different supplier, so it is at least not unique to one of them.
Repeat testing: if you want to verify the same lot a second time, testing with a different service strengthens the conclusion. Testing with the same service verifies reproducibility but uses the same method.
I have deliberately not rounded that, because the rounding is where the argument starts.
Independent measurement on a lot you bought yourself is the strongest evidence an individual can produce. Everything else is somebody else's sample.
Adding this to the thread rather than to the wiki, because I am not confident enough for the wiki.
Coming back to post #45, because the follow-up matters more than the original answer.
Taking submitting a sample seriously for a moment rather than deflecting: the honest position is that the community has observations and no controlled comparison, and those two things support very different sentences.
If someone has run submitting a sample properly I would rather read that than my own reconstruction of it. Posting mine only because the thread has gone quiet.
This follows post #51 rather than contradicting it.
Repeat determination on the same product line months apart is the measurement that speaks to consistency, and consistency is what most buyers actually want.
Submitting a sample is worth one more sentence than it usually gets, and the sentence is the one about how the number was arrived at.
What I would tell a new member reading about submitting a sample for the first time: the confident posts are not the reliable ones, and the reliable ones are longer.
I read post #55 twice before replying, because I had assumed the opposite.
The strongest argument against my own position on submitting a sample, stated as well as I can state it, since nobody else has yet.
Post #55 answers the question as asked. The question underneath it is different.
It does not extend to lots nobody has seen, it is not a recommendation, and it says nothing about anything other than what was measured.
A note on scope: what I am saying about submitting a sample applies to the case in the first post and I would not extend it further without checking.
Repeat testing: if you want to verify the same lot a second time, testing with a different service strengthens the conclusion. Testing with the same service verifies reproducibility but uses the same method.
I looked this up rather than remembered it, which is the right order.