Equivalent Scale to Gempro 250
- Thread starter jesilva
- Start date
I had GemPro 250 until they bought it back.
I am very happy with this one
I will publish a video of its repeatability if so you wish
I am very happy with this one
I will publish a video of its repeatability if so you wish
J.J. Coe
Silver $$ Contributor
A video would be great
Rocketvapor
Gold $$ Contributor
@Beiruty
I have one that LOOKS like that one.
I have really good check weights and was surprised that @ 1, 2, 3, 4----20 grams it would read EXACT.
Like WOW, reads check weights perfectly.
Problem is, it reads dead on the even gram with 1.001, 1.002, 1.003, 1.004.
If the load is close to an nice round number of grams the scale software makes it read the rounded number.
Anything close to the even grams it jumps to X.000.
For loads like 31 or 32 grains, which are NOT close to the even grams in weight it reads true +/- 0.02 grains.
For 2 grams, 30.864 grains or anything close it reads 30.86.
You can trickle and watch the scale jump from 30.80 grains to 30.86 grains to 30.92. Stay away from round number of grams and it is very close.
I have one that LOOKS like that one.
I have really good check weights and was surprised that @ 1, 2, 3, 4----20 grams it would read EXACT.
Like WOW, reads check weights perfectly.
Problem is, it reads dead on the even gram with 1.001, 1.002, 1.003, 1.004.
If the load is close to an nice round number of grams the scale software makes it read the rounded number.
Anything close to the even grams it jumps to X.000.
For loads like 31 or 32 grains, which are NOT close to the even grams in weight it reads true +/- 0.02 grains.
For 2 grams, 30.864 grains or anything close it reads 30.86.
You can trickle and watch the scale jump from 30.80 grains to 30.86 grains to 30.92. Stay away from round number of grams and it is very close.
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I ordered one, We will see if its any good. 20 bucks, win or loose.
Jim, I have a gempro 250 that you can have for free. Problem is, I moved to Chama a couple years ago. Keith
Huh?! I have a scale that will weigh 5 oranges or two grapefuits, but not 6 oranges but it will weight 3 grapefruit. It is called sensitivity threshold. how many grains in a gram?!
Rocketvapor
Gold $$ Contributor
Sorry to confuse everyone.
Will watch the video tomorrow.
going to bed but will watch the video.
I'll post one up for this scale also.
It counts by 1 milligram but will not display x.997, x.998, x.999, 1.001, 1.002, or 1.003.
To reduce confusion I'll only use Grams
.9, 1.9, 2.9, 3.9, etc.
Those same weights with 2 kernels of Varget.
Then 1.1, 2.1, 3.1, 5.1
Then those same weights with the 2 kernels.
The scale SEES the two kernals added.
Then to show the "Problem"
1, 2, 3, 4, 5 etc
Then those same weight with the 2 kernels (same ones as before)
and the scale indicates 1.000, 2.000, 3.000 and does not see the kernels.
Will watch the video tomorrow.
going to bed but will watch the video.
I'll post one up for this scale also.
It counts by 1 milligram but will not display x.997, x.998, x.999, 1.001, 1.002, or 1.003.
To reduce confusion I'll only use Grams
.9, 1.9, 2.9, 3.9, etc.
Those same weights with 2 kernels of Varget.
Then 1.1, 2.1, 3.1, 5.1
Then those same weights with the 2 kernels.
The scale SEES the two kernals added.
Then to show the "Problem"
1, 2, 3, 4, 5 etc
Then those same weight with the 2 kernels (same ones as before)
and the scale indicates 1.000, 2.000, 3.000 and does not see the kernels.
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Rocketvapor
Gold $$ Contributor
The scale's AtoD/softwear has missing bits at or near to whole number of grams.
Will ALWAYS read EXACT with whole number gram check weights. Pretty close between the whole numbers. Sensitivity is about/almost a single kernel of Varget anywhere within it's range, better than 2 kernels of Varget, EXCEPT near whole number of grams.
3 or 4 kernels @ the whole numbers and it sees the change.
Here's the video. Less than 4 minutes long.
My guess is that the scale uses a lookup table for Whole Gram digits, subtracts that from the AtoD input and measures the remainder as 0.000 to 0.999 and has low sensitivity, 3 or 4 counts, at the low end of the remainder measurement. Conversion to other units uses the gram value and calculates the new unit for the display.
Will ALWAYS read EXACT with whole number gram check weights. Pretty close between the whole numbers. Sensitivity is about/almost a single kernel of Varget anywhere within it's range, better than 2 kernels of Varget, EXCEPT near whole number of grams.
3 or 4 kernels @ the whole numbers and it sees the change.
Here's the video. Less than 4 minutes long.
My guess is that the scale uses a lookup table for Whole Gram digits, subtracts that from the AtoD input and measures the remainder as 0.000 to 0.999 and has low sensitivity, 3 or 4 counts, at the low end of the remainder measurement. Conversion to other units uses the gram value and calculates the new unit for the display.
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Thanks. I thought mine was dying but I think it might have been the cold in the garage. It is working fine now. I didn't know you moved from La Luz
I bought the one from the link in post #2. Its not accurate at all. once calibrated with the check weights, I can use the same check weights and its way off.
I have a Lyman scale weight check set and I weigh a 50gn weight. 1st weighing= 50.06 2nd weighing 50.04 if I add a 20gn check weight it reads 70.12
I have a Lyman scale weight check set and I weigh a 50gn weight. 1st weighing= 50.06 2nd weighing 50.04 if I add a 20gn check weight it reads 70.12
Rocketvapor
Gold $$ Contributor
Unless you KNOW the true mass of the check weights your results can be expected.
IF your 50 grain check weight was 50.06 grains, and your 20 grain check weight was 20.04 grains then 70.10 would be the expected result.
Check out this thread on relabeled Chinese check weight sets.
IF your 50 grain check weight was 50.06 grains, and your 20 grain check weight was 20.04 grains then 70.10 would be the expected result.
Check out this thread on relabeled Chinese check weight sets.
Actual weight of Lyman test weights
In January, a relative that works in a lab, called me and told me it was a little slow with everything going on but someone still has to be in the lab, to monitor the balances, as they are on 24/7. I told him I had a project for him to weigh some Lyman grain weights, plus some pennyweight and...
forum.accurateshooter.com
brokeasajoke
Silver $$ Contributor
Ultra class gold class 1, what ever all that means but hey it comes with a glove lol. I guess it's better than what comes in cheap weight kits. I have no way of knowing, but it gives me piece of mind.
D-4297
Gold $$ Contributor
Gee . I must be really lucky . I've had my GemPro 250 for about five years now , and it is just as accurate today , as the day I took it out of the box . I read about a lot of issues people have with them , and feel good mine isn't doing any of that stuff . I'll keep using it till it won't work correctly .
brokeasajoke
Silver $$ Contributor
I had to tare my gempro often. I sold it to help fund an fx120i. I have a sparker tuned beam scale as well. I find my self using my cheapest Frankford arsenal pocket scale the most coincidentally.
Rocketvapor
Gold $$ Contributor
That weight looks like a 50 gram, is it?
I have a few Class 1 standards that come out for critical work but mostly use an old S-1 set checked against the standards.
Then a few larger ones,
The cheap check weights available have been out paced by digital scales.
I have a few Class 1 standards that come out for critical work but mostly use an old S-1 set checked against the standards.
Then a few larger ones,
The cheap check weights available have been out paced by digital scales.
brokeasajoke
Silver $$ Contributor
Yes it's a 50g.
I use a 69 grain SMK bullet with a Sharpie mark circled around it, works for me.
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