I just got a jenning jsvg20 One question though. How do you guys test your scales for accuracy? I want to make sure it is on point. I re-calibrated it and then tried to test it with my 20 g calibration weight. After I did that I got a "EEE" which means I overloaded it (the max capacity is 20 g). I took it off immediately and am worried I could have damaged the scale or that the scale is simply off. Was this a bad idea to test it with the calibration weight? Do any of you use test weights? I cant seem to find too much online. I was thinking about using coins to test, but they're all slightly different. What do you guys use to make sure your scale is accurate?
You shouldn't test it with a 20G weight if the max is 20G. Though I seriously doubt you messed up the scale. Try weighing a few different nickels. They should come out about 5G each.
Yea the jennings is silly like that... its actually comes with a 20G calibration weight which you are suppose to use to calibrate it. The scale is capable of weighing over 20g, just that once its calibrated it wont display anything beyond 20G and instead will display EEEE. When you put that 20g weight back on after calibration it isn't unusual for it to read something like 19,998 or 20,002 (but it would display EEE for that). Sometimes it'll drift a few mg as well and then read something like 19,996 or whatever... its a cheap scale so its not perfect, but it works well enough for most common rc's. So dont worry, you haven't damaged it at all.
I used to have the Jennings - got it from OWK. I found it was most accurate if I used an intermediary (credit card worked nicely - 4.5 - 5.5g). DO NOT tare (zero) the scale. for whatever reason it seemed to have a greater tolerance (± 0.010g) if I were to tare the scale. Simply subtract your intermediary from the total weight.
The thing about testing with coins is they're still all slightly different. I weighed a few nickels and they all came out to different weights. How do I know my scale is calibrated right and is weighing things correctly? When I do weigh a nickel, there is no way for me to know that my scale is displaying its correct weight. Are there any cheap test weights I can buy out there? I know I sound paranoid. I'm just a very cautious person when it comes to this stuff....
yes, you can buy calibration weights of various sizes. They can be quite expensive depending on the class. For our purposes, you don't need anything extremely precise imo - especially considering the fact that you are working with a cheap scale that has a resolution of plus or minus 2mg... lots of room for error with your scale. Check out this link for an example... these are class 6 calibration weights (the lowest and cheapest class they offer). They sell them individually for about $8 dollars a piece in various sizes: http://www.scalesgalore.com/omass.htm#6a And if you scroll down just a bit further, they also offer kits containing many different sizes for decent prices. I'm not recommending this site as I've never used them... its just for an example of whats out there.
yeah i guess i wasn't thinking...nickels work for scales that weigh to the tenth of a gram, but probably not for mg scales. the scale i have access to is accurate to a tenth of a mg!
i really like mt american weigh a lot. its does its job well. was even accurate enough for meo dmt doses in the 5 to 15mg range.
"My Weigh" GemPro 250 3 minute warm-up and if used with an intermediary, tolerance is moot. Without an intermediary, tolerance approx. ±0.002g. With an intermediary and finely powdered substances, I've felt comfortable measuring to 0.002g for sub-gram (µg) substances using a liquid metric.
Wow, I didn't know 1 mg test weights exist. Those must be so fricken tiny. Does anyone have experience with mg. test weights? I'd prob get a 10 or a 20 mg one seeing how that's the range I'd be most concerned with. I might consider buying one. The shipping is more than the weight itself though.... I just found this set on ebay it's only $10. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330244235673&category=48727&refid=store
They are essentially small pieces of foil with the weight stamped on the foil. One edge is bent upwards as a handle, to be used with tweezers.
If they are just small pieces of foil with the weight stamped on wouldn't that cause the scale to read a higher weight than 1 mg?
