#test-results 2025-10-30

nice result

attach the pdf

post the lot, the purchase month, the lab, the number, and what you were expecting. that makes it useful later

do you test every order or sample it

i had a result i am fairly sure was a handling error on my side and i logged it as such

a supplier disputing a result is rare here and it has never gone well for the supplier

one bad test does not condemn a supplier. one good test does not clear one. both halves get ignored equally

is quantity testing available as a separate thing or bundled

coming back to this weigh the vial before you reconstitute. it costs nothing and catches the common failure, ymmv

follow up log the boring results too. a channel that only records failures produces a false picture

the results in this channel skew because people test when they are suspicious. that is selection bias and it is real

i have never regretted spending the money on a test. i have regretted not testing twice

if the vial has been through a bad transit you are testing the transit as much as the supplier

unrelated but the honest limits: hobby chain of custody is weak and any result here should be read with that in mind, i think

anyone tested the same lot twice at different labs

update on the earlier thing my sheet has 8 lots from FGP with a spread under a point, which is tight

which lab

is anyone tracking results over time in a way they would share

has a supplier ever disputed a result posted here

certificate said 99.4 and the independent came back 96.8, is that a problem

quantity testing is usually a separate line item and it is the one worth paying for

is it worth testing if the vial has already been through a warm transit

the widest spread in my data is about 2.6 percentage points across five lots from one supplier

99.2 against a certificate of 99 is fine. the same supplier landing low four times in a row is a question

a result without a lot number and a purchase date is an anecdote with a pdf attached

how do you post a result so it is actually useful to somebody in a year

does anyone log the negative results, the boring ones

i test roughly every tenth vial. it is a sampling strategy, not paranoia

whats the underfill rate people are actually seeing

what interests me is when the gap goes the same direction every time. once is noise, three times is a pattern, n of 1 obviously

my result contradicts the supplier certificate, do i tell them

my read after three years of this: purity is mostly fine across the market and fill consistency is where suppliers differ

does a bad result on one lot condemn the whole supplier

follow up i told SSA about a result they would not have liked and they did not argue. credit where it is due

do the results in this channel skew because people test when suspicious

how do you separate batch variance from supplier variance

posting my VendorInvestigate result on lot H-2814, what do people make of it
a single sample tells you about a single vial. that is genuinely all it tells you

a single sample tells you about a single vial. that is genuinely all it tells you

sample handling on your end absolutely affects it. draw cleanly, ship fast, do not let it sit warm, n of 1 obviously

selection bias

anyone had a result they think was a lab error rather than a bad vial