GTA
Target Shooting Matches, Discussion & Events => Target Shooting Discussion Gate => Topic started by: strever on November 02, 2014, 10:55:23 PM
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i know this has been discussed B4 but
i have gone thru 5 different digital scales now
starting with cheap ($15.00) and working up in price
and they ALL seem to have the same problem
not one of them can weigh the same pellet the same in 5 times of weighing
all 5 scales are +/-.01 in grain weighing
the last one almost $75.00 is actually worse then one of the $20+.00 one
have i been too cheap ?
is there a favorite digital scale that repeats ?
thanks
Dick
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the first one I brought the aws-600-sil was cheap and didn't measure down to the weight I needed.
I then brought the aws gemini-20 milligram scale, was 50.00 but very acurate and much better.
(http://harryb.myftp.org:9090/scale3.jpg)
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i tried the gemini 20 as one of the 5 ;D
try weighing the same pellet multiple times and see if it repeats
if yours does repeat then mine is a dud
the first one I brought the aws-600-sil was cheap and didn't measure down to the weight I needed.
I then brought the aws gemini-20 milligram scale, was 50.00 but very acurate and much better.
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yes, I double weighed them when I first got it to make sure it was consistant. I also used a new battery.
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I never have trouble with the cheap ones at home or in the lab.
With measurements this small you can expect insignificant fluctuations caused by such things as internal rounding and the occasional vagrant breeze. If you use the tare function with a weigh paper, and recalibrate frequently your weights should be acceptably consistent with most any scale costing between ten and fifty dollars.
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David
how often do you recalibrate when weighing a tin of 500 pellets ?
i don't understand the tare function with a weigh paper ?
rounding does not make sense when the diff is more then 10 gr
and i weigh in a large closet = no breeze
i will try a new battery to see if i have better luck
I never have trouble with the cheap ones at home or in the lab.
With measurements this small you can expect insignificant fluctuations caused by such things as internal rounding and the occasional vagrant breeze.
If you use the tare function with a weigh paper, and recalibrate frequently your weights should be acceptably consistent with most any scale costing between ten and fifty dollars.
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Your scale is likely accurate to plus or minus .01 gram. That's plus or minus .154 grains, giving you an expected variation of approximately .31 grains plus the scale's rounding error. Ten grains is an enormous difference.
If the battery swap doesn't fix the problem, you've likely got a defective or damaged scale. The usual causes of damage are moisture and/or stress on the plastic parts under the platform. A light squeeze will do the latter as quickly and permanently as weighing something beyond the scale's capacity. Using the "cover" for storage and transport should go a long way towards preventing physical damage.
To use the tare function......turn the scale on - place your weigh paper on the platform and wait for its weight to register - press the tare button - wait for the scale to "zero" - center the item to be weighed on the platform - record the weight - remove the item - repeat
Unless I've decided to live with error, I recalibrate frequently using a 50.00g standard. The last time I weighed pellets, that amounted to five or six times per .25 tin.
All scales are susceptible to damage. I buy the cheap ones so I can replace them when broken without also breaking the bank.
Finally, I would be less trusting of any scale used to weigh powder.
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David
i have only purchased .001 g scales knowing .001g accuracy would supposedly give me at least .02 gr accuracy
typical of these poorly repeating scales is this one http://www.ebay.com/itm/290370892943 (http://www.ebay.com/itm/290370892943) which i also tried :(
and my scale does not leave the table once placed in my large closet where i do pellet sorting
thank you for the paper weigh explanation, but what is a weigh paper ?
when you put digital powder scale in to Ebay approx 200 scales show up
http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_sop=16&_nkw=digital+powder+scale&_pgn=2&_skc=50&rt=nc (http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_sop=16&_nkw=digital+powder+scale&_pgn=2&_skc=50&rt=nc)
i have tried almost all of the cheaper ones under $100.00
the Gemini 20 is the best one so far and i will change its battery's tonite and do some more testing
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I have the one below for weighing powder for reloading pistol ammo and use it for pellets also. It weighs the same time after time after time...........$107.99 at Midway
RCBS RangeMaster 750 Electronic Powder Scale 750 Grain Capacity 110 Volt
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Some/many scales actually measure in grams, then they do a gram to grain conversion to display the weight in grains. There are instances where the display may skip a weight (ie goes from .3 grain to .5 grain, never showing .4 grain). So if you want to test repeatability, you might try the grams mode first.
Here is my conversion chart (col1=weight in grams, col2=weight in grains to 5 decimal places, col3=weight in grains to 1 decimal place)
1 15.43236 15.4
0.99 15.2780364 15.3
0.98 15.1237128 15.1
0.97 14.9693892 15.0
0.96 14.8150656 14.8
0.95 14.660742 14.7
0.94 14.5064184 14.5
0.93 14.3520948 14.4
0.92 14.1977712 14.2
0.91 14.0434476 14.0
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I know this is an old topic, but I wanted to share the scale I use to weigh pellets. :) It weighs 0.002 grains, so I know hitting .1 is easy. :)
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the scale i finally settled on is
the Gempro 250 a reasonable priced scale that will repeat plus
i have a transformer on mine so i don’t worry about batteries
https://www.google.com/#q=Gempro+250 (https://www.google.com/#q=Gempro+250)