The ol' "round robin"!And also send the same UOA sample to another test lab to compare different lab's results.
The ol' "round robin"!And also send the same UOA sample to another test lab to compare different lab's results.
You laugh. The days I ran the ICPMS I couldn't wear deodorant as even with a lab coat the aluminum in the deodorant would cause measurable contamination. Our ammonia technique was so sensitive that you set up the run and left the lab because the ammonia in your breath would contaminate the samples.What happens if one is taking vitamin or Iron supplement and contaminates the sample?![]()
I think last time I went to the range my shooting it was a combo of all 4 HAHAHA.Another good one (with added info) showing what accuracy and precision are defined to be.
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That's like the enviro samples, ppb. We would have blanks ("trip blanks") that were a vial of deionized water that got delivered with the sample containers, went to the field, then back to the lab and analyzed to look at things like this. The mineral; exploratoin work is very different but we still send in inert blanks (often just pure quartz) to be run to have a look at well the lab cleans their equipment.You laugh. The days I ran the ICPMS I couldn't wear deodorant as even with a lab coat the aluminum in the deodorant would cause measurable contamination. Our ammonia technique was so sensitive that you set up the run and left the lab because the ammonia in your breath would contaminate the samples.
Of course we're not talking about UOA level detection limits here. We were working in low single digit parts per billion, parts per trillion, and even into the parts per quadrillion with the ICPMS.
Ed
Z,Another good one (with added info) showing what accuracy and precision are defined to be.
View attachment 231870
I think they said it's "high accuracy" because all the shots are exactly the same distance away from the bullseye. The precision is obviously really bad because all the shots are not grouped closely together like in the lower LH example (high precision & high accuracy). The example in post 40 is more clear.Z,
I have a hard time with the "high accuracy" of the lower right image.
Closeness of the 5 shots to the bullseye in this image, is worse than the upper right image, which was given as a "low accuracy" example!
Re: Lower Right Image
Could it be that they meant to have the shots (red marks) on the most inner yellow circle as opposed to the outer yellow circle? Meaning the exact same relative shot locations but on the most inner yellow circle instead?
I think they said it's "high accuracy" because all the shots are exactly the same distance away from the bullseye. The precision is obviously really bad because all the shots are not grouped closely together like in the lower LH example (high precision & high accuracy). The example in post 40 is more clear.
Yes, they could have made the lower RH example better, like the other examples show for that case.Please see my edit.
I have a feeling they wanted the shots on the most inner yellow circle!
First off to be clear, I don't know or care how this applies to oil analysis....... With that said, when someone makes the statement that a rifle is "accurate", it means it is capable of placing shot after shot in the tightest group possible.
These were shown because the discussion was about the accuracy and precision of UOA test data. Could be applied to anything that is measured.First off to be clear, I don't know or care how this applies to oil analysis.......
Yeah, that's shown in the accuracy & precision examples, which are pretty self explanatory - and are correct. As shown in the examples, a rifle (or anything else) could be very high precision, but not be accurate.With that said, when someone makes the statement that a rifle is "accurate", it means it is capable of placing shot after shot in the tightest group possible.
That's technically both accurate and precise, just as the examples show.ACCURATE :
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I'd say that's inaccurate and also not precise at the same time.INACCURATE :
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The guy that wins is the one that has both accuracy and precision. One could shoot a very tight group (ie, precision), but that group could be far way from the bullseye ... ie, inaccurate. Accuracy and precision are two separate unrelated things. Having both is the goal.Benchrest competition is a good example of this. Benchrest rifles are considered to be some of the most accurate rifles in existence. The man / rifle combination that shoots the tightest group wins.
Not really. Because in Benchrest competition, it doesn't matter where the grouping prints on the target. Or where the gun is "sighted in", as you put it.The guy that wins is the one that has both accuracy and precision. One could shoot a very tight group (ie, precision), but that group could be far way from the bullseye ... ie, inaccurate. Accuracy and precision are two separate unrelated things. Having both is the goal.
This guy won ... had both accuracy and precision.
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This guy didn't win ... he should have sighted the sites in better to make it accurate, but it shot very precisely.
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I have to admit it's not a very good example, because it's a target I shot at 25 yards with a Sig P-226 with cheap, bulk factory hardball ammo.I'd say that's inaccurate and also not precise at the same time.
I'm giving examples of precision and accuracy. What you are describing here is only precision. Technically speaking in this instance, it's the guy with the most precise rifle that wins. If that tight group was hitting exactly were the intended goal was to make that tight group hit (like the bullseye being the goal), then the rifle would be both precise and accurate. There is a distinct difference between precise and accurate, and they are two separate unrelated things.Not really. Because in Benchrest competition, it doesn't matter where the grouping prints on the target. Or where the gun is "sighted in", as you put it.
The tightest group wins... Period. This regardless of where the group is shot on the paper. All that matters is who shot the tightest group. And that will always be the guy with the most accurate rifle / load combination.
No, again ... it's the precision of the rifle you're talking about. Yes, there is some "shooter" (operator) skill factor too, but if you put the rifle in a good gun vice and shot it 10 times and it had a very tight group then it would be a "precise" shooting rifle. If it didn't have a tight group, it would not be considered very precise. This is the shooting MOA of the gun itself, without any human factor involved. The MOA of the rifle is defining how precise it shoots.This is because it really doesn't take any skill to dial in a scope where to print off a rest. The talent that is required to win these matches is derived by the skill of the handloader, and the accuracy of the rifle.
Not really ... it's a discussion to properly understand the distinct difference between precision and accuracy. If bench shooting is refereed to as "Precision Benchrest Shooting" then they are correct with that terminology if all they are looking at is the grouping and not concerned at where that group hits the target. They are looking only at the precision (both gun and operator) and not caring about where the gun's sighting system is adjusted to place the group on the target.To be perfectly honest, this whole exercise amounts to picking fly crap out of the pepper. Because the sport of benchrest shooting is often referred to as, "Precision Benchrest Shooting"....
No ... it actually takes a precise shooting rifle to compete and win if all they are judging is the grouping, regardless of where the shot group is on the target ... like this previous example.But it takes a very accurate rifle to compete and win.
Sorry ... they are also technically using the wrong terminology. They may purposely use the wrong term because that's what people are use to seeing, and don't really understand the difference between precision and accuracy. A rifle's MOA performance is only describing how precisely it shoots. The accuracy is dependent on the sights and if they are "calibrated" (ie, "sighted in") correctly to put the bullets where the shooter wants them. Accuracy is basically adjustable, but the precision isn't ... it's part of the design and manufacturing of the rifle ... you get what you get in terms of its precision - its MOA performance."Weatherby Guarantees SUB-MOA Accuracy within Two-Years of Verified Purchase Date to Original Purchaser".
"Together, the Weatherby system (premium ammunition and rifle) forms the flattest shooting, hardest hitting, most accurate combination in the industry today.
Accuracy Guarantee – Weatherby, Inc.
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