Instrument Validation
Instrument Validation
(OP)
Hi all,
Here's my situation: I have to measure the density of a liquid in my process. The specification is 1525 g/L +/- 2.5 g/L. The instrument that I have been given to measure the density reads from 1500-1600 g/L, in increments of 2 g/L.
I do not feel that the instrument is the right one for this process due to the fact that the graduations are 40% of the total spec range. My biggest problem is that I need some very solid proof of this because both the spec and the instrument have been given to me by another of our plants that "invented" the process, and they do not listen to requests for change without some type of proof. Are there any tests that I can perform to prove my claim one way or another?
Here's my situation: I have to measure the density of a liquid in my process. The specification is 1525 g/L +/- 2.5 g/L. The instrument that I have been given to measure the density reads from 1500-1600 g/L, in increments of 2 g/L.
I do not feel that the instrument is the right one for this process due to the fact that the graduations are 40% of the total spec range. My biggest problem is that I need some very solid proof of this because both the spec and the instrument have been given to me by another of our plants that "invented" the process, and they do not listen to requests for change without some type of proof. Are there any tests that I can perform to prove my claim one way or another?





RE: Instrument Validation
If your ruler measures down to 0.01, then you are acurate to 0.1.
Having spent years in a quality lab as a metrologist, that is a pretty safe rule to live by.
RE: Instrument Validation
http://www.astm.org
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Instrument Validation
Cheers
Greg Locock
RE: Instrument Validation
RE: Instrument Validation
That's the PRECISION, you still have said nothing about the UNCERTAINTY.
TTFN
RE: Instrument Validation
m777182
RE: Instrument Validation
For example, perform a gage R&R study with your current device plus another one that has better resolution. Then compare the two. You should see some examples where the current device rejected formulations that were actually good, or vice versa. You can then convert this into $$$$ the business is losing, which is definitely something that will be listened to.
Good luck!