Lateral-flow devices: like a rapid COVID test. They have a reagent strip and produce a colour result. They are quick but not precise and not intended for quantitative work.
On the subject in the title: Reflectance and photometric devices: precision in practice Working notes rather than a conclusion.
I was wrong about reflectance and photometric devices in a thread last spring and I would like to correct it publicly rather than quietly.
The error was in the units, which changed the conclusion by an order of magnitude. Setting out the corrected version, and the way I now check for that class of mistake.
The arithmetic in post #2 is right; the assumption feeding it is the part to check.
Precision of home tests: most consumer-accessible devices are not precise to the level people want ("is this 99% pure or 97% pure"). They give a yes/no or a rough category, not a quantitative number.
None of the above is medical advice and I am not qualified to give any.
| Topic | Participants | Replies | Views | Activity |
|---|---|---|---|---|
|
Coming back to: What consumer-accessible tests can and cannot determine
Asking directly, because I could not find a straight answer: What consumer-accessible tests can and cannot determine Something about consumer-accessible tests does not reconcile and I would like a second pair…
|
+4 | 8 | 25k | 22mo |
|
Lateral-flow and colorimetric approaches: the specificity problem
Lateral-flow and colorimetric approaches: the specificity problem — setting out what I have, and where I think it stops being reliable. Lateral-flow and colorimetric approaches, and specifically the version…
|
2 | 4k | 9mo | |
|
Coming back to: Why quantitation is the hard part, not detection
Why quantitation is the hard part, not detection — that is the question, and I have not found it answered plainly anywhere I have looked. Collecting what is known about quantitation in one place, because it…
|
+86 | 92 | 54k | 8mo |
|
What consumer-accessible tests can and cannot determine — a second dataset
What consumer-accessible tests can and cannot determine — a second dataset I have a specific reason for asking rather than idle curiosity, and the context is below. Posting a small dataset on…
|
+117 | 131 | 45k | 10h |
|
Reading a home test result without over-claiming — what changed since
On the subject in the title: Reading a home test result without over-claiming — what changed since Working notes rather than a conclusion. What changes if the standard account of Reading a home test result is…
|
2 | 12k | 6mo |
| Topic | Participants | Replies | Views | Activity |
|---|---|---|---|---|
|
Coming back to: What consumer-accessible tests can and cannot determine
Asking directly, because I could not find a straight answer: What consumer-accessible tests can and cannot determine Something about consumer-accessible tests does not reconcile and I would like a second pair…
|
+4 | 8 | 25k | 22mo |
|
Water content on a certificate and why it changes the arithmetic — what changed since
On the subject in the title: Water content on a certificate and why it changes the arithmetic — what changed since Working notes rather than a conclusion. What changes if the standard account of Water content…
|
3 | 801 | 8mo | |
|
LOD and LOQ: definitions people get wrong
LOD and LOQ: definitions people get wrong — setting out what I have, and where I think it stops being reliable. What changes if the standard account of LOD and LOQ is wrong? I ask because I have been treating…
|
2 | 43k | 8mo | |
|
Revisiting: Sample handling between despatch and injection
Posting this under the heading it deserves: Revisiting: Sample handling between despatch and injection Everything below is what sits behind that. Reading back through what has been written here about Sample…
|
+5 | 9 | 1.1k | 6mo |
|
Why this community will not facilitate a group purchase
Asking directly, because I could not find a straight answer: Why this community will not facilitate a group purchase Currency and fees, set out so that the comparison can be checked. Quoted amount, conversion…
|
2 | 40k | 3mo |