Second pass at: The mass-error checker and its intended scope posts 61–75
This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1 · go to the accepted answer.
Post #60 and I disagree about the size of the effect, not about the direction.
A saved calculation is worth more than a remembered one. Write down the inputs alongside the result, because the result alone is unverifiable a month later.
It is worth checking rather than assuming, which costs nothing.
The documentation on mass-error checker is better than this thread and I say that as someone who has posted in the thread.
Tools that run entirely in the browser send nothing anywhere, which matters more to some people here than others and is worth stating either way.
Post #64 put the caveat in the right place and I want to underline it.
The claim about mass-error checker upthread is stronger than its source supports. I have read the source. The source says "associated with" and the post says "causes".
The arithmetic in post #66 is right; the assumption feeding it is the part to check.
Significant figures in the output should not exceed what the inputs support. A concentration calculated from a nominal vial mass is not known to four decimal places.
A guess, clearly labelled as one.
Collapsed as off-topic by two members at trust level 3 or above
The parts-per-million mass-error calculation is simple enough to do mentally to one significant figure, which is a good habit because it catches an order-of-magnitude slip immediately.
Scoping that to what I have actually seen rather than what I have read.
Practical experience of mass-error checker, offered as one case with the conditions stated, not as a general finding. Conditions first, because they are what make it interpretable.
Where I part company with post #67, and it is a narrow parting.
Dose equivalence calculator: compounds have different potencies. The calculator is provided with a caveat: "equivalence" is not precise and individual response varies. It is a rough starting point, not a dose prescription.
The part I am sure of is shorter than the part I have written.
Post #71 is the version of this I will quote in future. One addition.
Taking mass-error checker 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.
The reason mass-error checker keeps being re-asked is that the answer is conditional and people quote it without the condition. It is not that the answer is unknown.
I had written a reply contradicting post #71 and deleted it. Here is what survived.
Unit-conversion tools are only as good as the assumption they make about the syringe. Ask what barrel and what graduation interval it assumed before trusting the units figure.
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