A&D FX-120i scale - No one has mentioned...

DownhillFromHere

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Nov 30, 2017
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... that buyers also need to order, or have on hand, a 100-gram (gram, not grain) or a 50-gram check weight to calibrate the scale.

I received my scale promptly (4 days to central NC) from Cambridge Environmental Products in Canada, for $485 shipped (using discount code "CAMBRIDGE" as shown on this page from their web site). I knew I needed a check weight, but I did not read the documentation carefully enough before ordering. I thought I could use a 50-grain weight. NO. For this model, a 50- or 100-gram weight is required.

CE Products offers a 100gram weight for $15... probably makes most sense to order one with the scale. Cheaper ones are available - but my question is how close to 100 grams those weights actually are. Yes, device consistency trumps check weight super-precision, but if we're going to order a super scale, does it make sense to skimp on calibration weight?

Observations on my uncalibrated scale: With check weights, I observed a consistent, repeatable 0.04-grain overage per 10 grains. In other words, whatever combination of weights I used to total 10 grains or multiples of 10 grains consistently, repeatably produced 10.04 / 20.08 / 40.16 grain readings.

So now I'm off to order a check/calibration weight.
 
Mine came calibrated, however, when recalibrated it was off by over 1/2 grain. I used a class 1 100 gram weight. expensive but worth it. You can also find some used Class 1 calibration weights for a better price.
 
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Regarding calibration weights and how close the actual weight matches the nominal value. You mention the $15 one and "cheaper". Anything in that price range will not come with a certification as to accuracy or an actual value. Something that is certified is probably 10x the cost of an uncertified example. My point is... spending a tiny bit more probably doesn't give you anything better.

With that being said, I think most find the cheap ones pretty close to the nominal weight. And as you say, it's more about consistency. Calibrate using the same weight and you should get consistent results. In short, I would say to not obsess over the accuracy of your weight... unless things like not knowing the actual accuracy bothers you. It does me, so I just had my cheap weight weighed on a lab scale that was calibrated via a certified weight. My cheap weight ended up being VERY close to the nominal value. Better than its advertised accuracy.
 
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Thanks for responses @DDRH65CM and @EnjoyTheWilderness . There is a lab equipment supply business nearby whose web site shows both ASTM Class 1 and NIST Class F weights in stock; I'll swing by and pick one up tomorrow. The Class F 100-gram weight is significantly cheaper ($48) than the Class 1 ($93).

Good info about weight classes here.
 
Can you just use the calibration weights that come with a Chargemaster? I have an A&D coming and will have to order a weight if in can’t use the ones from the CM. Thanks
 
Adams sometimes offers a Class 2 weight that is actually a Class 1. It just does not have the certification. They are not always available. $50 shipped when available. I think they are overruns they just don't bother to print certs for. Comes in the same package as the Class 1s that are about $100. I use the Class 1s at work and use the Class 2s at home. On our company lab scales the measure out exactly the same on both. Hope this helps.
 
Mine came with a weight
Did yours come from CE in Canada? I just checked the packing boxes again - no weight in mine.

Adams sometimes offers a Class 2 weight that is actually a Class 1. It just does not have the certification. They are not always available. $50 shipped when available. I think they are overruns they just don't bother to print certs for. Comes in the same package as the Class 1s that are about $100. I use the Class 1s at work and use the Class 2s at home. On our company lab scales the measure out exactly the same on both. Hope this helps.
Thanks, yes, all input is useful - to me and SH at large. I worked in the pharma industry for the better part of 30 years (IT side) and spent time in the labs. I had a pretty good idea that there is more to obtaining a 100-gram weight than a layman would think - how close to 100 grams are you willing to pay for? Buying an FX-120i and calibrating it with a $6 weight is, to me, a bit like buying a Vudoo .22 and feeding it Thunderbolt ammo.

Biggest aggravation now is waiting. The local lab supply house drop-ships the weights - they don't stock them, which is not surprising. I can use the scale by applying an offset calculated with my little Lyman check weight set - there has been zero drift; as stated in my first post, the 10-grain weight and 10-grain multiples in any weight combination reads 10.04 / 20.08 / 40.16 grains every time.
 
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Not sure why some of you guys are worried about getting class 1 weights? As long as you use the same calibration weight every time to register the scale, it doesn’t matter if the weight is 99.5 grams or 101 grams, it should have a consistent calibration and zero after each use.
While I agree completely with the consistent baseline, it's important to note there are 15.4324 grains in a gram. So, a 0.25% (one quarter of one percent) error in the check weight's actual weight would give measurments almost 4 full grains high or low.

Since I share loading data with friends and post here, and I've purchased a highly capable measuring device, I'm not taking a chance on a cheap weight. It's a one-time purchase.
 
Because I share loading data with friends and post here. Since there are 15.4324 grains in a gram, a 0.25% (one quarter of one percent) error in the check weight's actual weight would have me giving measurments almost 4 full grains high or low.

Um, no.
And you guys all run the exact same calibration weights and exact same loads between rifle? I find that hard to believe, but I guess anything is possible.

For most guys, a class 1 weights just means your pocket book Is going to be lighter. Total overkill.
 
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Not sure why some of you guys are worried about getting class 1 weights? As long as you use the same calibration weight every time to register the scale, it doesn’t matter if the weight is 99.5 grams or 101 grams, it should have a consistent calibration and zero after each use.

Never crossed my mind of using a none certified weight. I mean, if I’m gonna spend close to 2 grand on V3 AnD FX120i setup cause I’m all for precision, I ain’t skimping anything. These FX scales are lab scales. Use lab certified weights. Go all all the way. Almost like, why would anyone buy a $6k rifle, and put a $800 dollar scope with $100 rings?
 
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As @spife7980 said, if the CM weights total 50 grams or 100 grams, you're good to go. The FX-120i requires exactly 100 grams or exactly 50 grams.
It does by default support a 50 or 100 gram weight. And your point is correct that you need one of those two from a nominal perspective. But to add to the story...If you know the actual value of your weight (say your nominal 100 gram actually weighs 99.997 and you might know this via official certification documents, or by weighing it on a scale that has been calibrated by using a certified weight), you can set update the scale with your actual value. It supports a bit of plus or minus from those two nominal values.

I know that for some, none of this makes sense. But getting this type of calibration accuracy is not hard or particularly expensive (in the grand scheme of things). So for those of us who do care... the ability to do this exists.
 
Never crossed my mind of using a none certified weight. I mean, if I’m gonna spend close to 2 grand on V3 AnD FX120i setup cause I’m all for precision, I ain’t skimping anything. These FX scales are lab scales. Use lab certified weights. Go all all the way. Almost like, why would anyone buy a $6k rifle, and put a $800 dollar scope with $100 rings?
Sure if you’re using your scale for quantitative chemical analysis I completely agree. For load work up? As long as I can repeat my work over and over again, I could give two shits if it’s class 1 check weight.
 
Sure if you’re using your scale for quantitative chemical analysis I completely agree. For load work up? As long as I can repeat my work over and over again, I could give two shits if it’s class 1 check weight.
Everyone broadly assumes the only use for these scales is to weigh powder. And in that scenario, there may not be a need given everyone is going to have a load that works for them. So the accuracy may not be needed. Consistency and repeatability are more important. But if you are doing things like water weight of cases (as one example), then accuracy of that data might matter for someone who looks at any data you share.
 
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Everyone broadly assumes the only use for these scales is to weigh powder. And in that scenario, there may not be a need given everyone is going to have a load that works for them. So the accuracy may not be needed. Consistency and repeatability are more important. But if you are doing things like water weight of cases (as one example), then accuracy of that data might matter for someone who looks at any data you share.
Why would water weighing cases be an example where it matters? You’re weight sorting brass based on a measured internal volume. The check weight wouldn’t affect this.
 
Why would water weighing cases be an example where it matters? You’re weight sorting brass based on a measured internal volume. The check weight wouldn’t affect this.
What if it's not about sorting which is a relative operation, but calculating an absolute value? Maybe you want to use the case volume as input for internal ballistics calculations in which having accurate values (via absolute values) matters.

Listen, having a certified calibration weight is not a requirement. I dont think anyone is saying that. If you dont think it provides you any value, and for you and many others it may not, then dont worry about it.
 
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