a point or two between the certificate and an independent result is inside what two labs disagree by
#test-results 2026-05-18
Monday22 messages4 participantstimes are UTC
Highlights from this day
- vale_vials — ok so i told QST about a result they would not have liked and they did not argue. credit where it is due 21:49
- underfill_uma — a single sample tells you about a single vial. that is genuinely all it tells you 22:13
- warsaw_vial — weigh the vial before you reconstitute. it costs nothing and catches the common failure 22:40
ok so i told QST about a result they would not have liked and they did not argue. credit where it is due
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i had a result i am fairly sure was a handling error on my side and i logged it as such
[edited]when did you buy it
log the boring results too. a channel that only records failures produces a false picture
one bad test does not condemn a supplier. one good test does not clear one. both halves get ignored equally
nice result
a result without a lot number and a purchase date is an anecdote with a pdf attached
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whats the worst result anyone has logged and what happened next
96.8 against a certificate of 97.4 is fine. the same supplier landing low four times in a row is a question, ymmv
a single sample tells you about a single vial. that is genuinely all it tells you
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i have never regretted spending the money on a test. i have regretted not testing twice, someone check my working
the honest limits: hobby chain of custody is weak and any result here should be read with that in mind
i test roughly every tenth vial. it is a sampling strategy, not paranoia
fridge-thermometer.png
800 × 800 · 774 KB · not retained in the public archive
posting my VendorInvestigate result on lot H-2814, what do people make of it
assay under label with good purity means you got less of the right thing. that is a fill problem, not a synthesis problem
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how many lots do you need before you can say anything about a supplier
the widest spread in my data is about 2.6 percentage points across five lots from one supplier, still working it out
for the archive is a purity-only test worth the money if underfill is the common failure
ok so my read after three years of this: purity is mostly fine across the market and fill consistency is where suppliers differ
what interests me is when the gap goes the same direction every time. once is noise, three times is a pattern, anyway
weigh the vial before you reconstitute. it costs nothing and catches the common failure
| Evidence | Counts? |
|---|---|
| Independent report, lot you bought, lot number legible | yes |
| Independent report, no lot number | no |
| Supplier certificate only | no |
| Screenshot of a report | no |
| Blinded pooled submission | yes, for the pool |
| A friend who said it was fine | no |