Lazyscience
Bluelighter
what is this? is it when you dissolve a known amount into a known volume of solution to get an accurate small dose?
☛ Official ☚ The Big & Dandy Scale / Balance Thread - Part 2.000±
- Thread starter frasierdog
- Start date
what is this? is it when you dissolve a known amount into a known volume of solution to get an accurate small dose?
Transform
Bluelight Crew
- Joined
- Sep 5, 2010
- Messages
- 4,804
Quite right. You dissolve several doses in a known amount of liquid, then use a volume measure (syringe or pipette) to divide it.
Accurate volume measures are much easier to get than accurate weight measures so that's why we suggest it.
For something like 2C-B I would weigh 100 mg out, then dissolve in 10 mls of vodka. You can then use a small syringe (easily had from ebay or a drugstore) to measure it, and 1 ml will contain exactly 10 mg.
Accurate volume measures are much easier to get than accurate weight measures so that's why we suggest it.
For something like 2C-B I would weigh 100 mg out, then dissolve in 10 mls of vodka. You can then use a small syringe (easily had from ebay or a drugstore) to measure it, and 1 ml will contain exactly 10 mg.
love_child
Bluelighter
Just bought a scale guys... which weight setting to I set it to for trying to get a 100-125 mg dose?
It has alot of different settings but if I put it go grams I am looking for it to be 0.10?
Thanks!
It has alot of different settings but if I put it go grams I am looking for it to be 0.10?
Thanks!
SabbathViper
Greenlighter
- Joined
- Feb 2, 2012
- Messages
- 28
I'm considering getting the Acculab VIC-123, but am also considering the GemPro250. The Acculab is more expensive by a fair margin.
I've been using the cheap-o Gemini-20, and honestly speaking, this thing has been (thus far) accurate to .2 mg. I know it sound silly, but maybe I got one of the better ones of the lot. However, it is pretty cheaply made, and I want something quality which I know I can trust irregardless of battery life, etc. So for those of you who can compare, what have you heard about these two? I have heard less negative reports about the Acculab compared to the GemPro250. It seems that sometimes you get a bunk 250, but most people seem to report spot-on .001 accuracy with the Acculab.
Is it worth the money?
I've been using the cheap-o Gemini-20, and honestly speaking, this thing has been (thus far) accurate to .2 mg. I know it sound silly, but maybe I got one of the better ones of the lot. However, it is pretty cheaply made, and I want something quality which I know I can trust irregardless of battery life, etc. So for those of you who can compare, what have you heard about these two? I have heard less negative reports about the Acculab compared to the GemPro250. It seems that sometimes you get a bunk 250, but most people seem to report spot-on .001 accuracy with the Acculab.
Is it worth the money?
This is the scale I use, its under $20 and you can buy it at amazon.
American Weigh DIA20 Digital Carat Scale, 100 by 0.005 CT
http://www.amazon.com/gp/product/B003STEJCU/ref=oh_o02_s00_i00_details
I think its good enough for taking MXE which dosages for me at least range from 25mg to 150mg.
American Weigh DIA20 Digital Carat Scale, 100 by 0.005 CT
http://www.amazon.com/gp/product/B003STEJCU/ref=oh_o02_s00_i00_details
I think its good enough for taking MXE which dosages for me at least range from 25mg to 150mg.
love_child
Bluelighter
Thanks but when I set it to grams it only displays it from 2 decimal points. When I was trying to weigh out 120mg it showed up as 0.12
love_child
Bluelighter
Thanks for the help
Cheers
Cheers
Moss on a rock
Greenlighter
- Joined
- Feb 15, 2011
- Messages
- 4
In this post, I want to discuss what Ive learned about milligram scales, their technology and how to use them in respect to their limitations. After reading through this thread, I think I have something to add to this discussion that people will find helpful.
From what Ive read about digital scales, linearity is a quality that one really wants to consider when buying a scale as well as what sort of load cell technology the scale has. The load cell has a lot to do with the price and performance/engineering of a scale. The linearity tells you how accurately the scale will measure the wieght of a mass each time you put it on the scale- margin of error of each measurement. Notice that I am using the terms accuracy and performance to mean different things. Accuracy means how well it works and performance means how it can be expected to function.
Reality check: Alot of people get upset with the scale they bought because they dont understand how it is engineered to perform. Here's a great video on this subject that better explains what I mean:
hxxp://www.youtube.com/watch?feature=player_embedded&v=89BOlViQXto
From watching the video, you quickly understand why some people get upset with their high dollar scale they bought, that uses strain gauge technology, because it won't register changes in the weight when the user is slowly adding small amounts of some powder. The video demonstrates that. Obviously, the problem isnt the lack of sensitivity of the scale but rather the way the software of the scale was engineered to perform and is well explained in the video.
What this video doesnt tell you is how to add small amounts of stuff to what you are trying to weigh, when using a strain gauge scale, and get a new measurement instead of having the thing sit there and register no changes, which is what a lot of people bitch about. What I have found to work is to remove the weighing tray holding your stuff from your scale. Then add a small amount of stuff to the mass on the tray. Then return the tray to the scale to see how much you just added. If you still dont have the measurement you want, remove the tray, add or remove some stuff to/from the tray. Then replace the tray on the scale to see what you've got and so on. You get my point: remove the tray from the scale before adding or removing stuff to finely adjust your total mass, then return the tray to the scale to get a new measurement. Practice this with some salt or sugar or tea leaves as they did in the video. With a little playing around with your scale you should get an idea of how to use it to reliably to get the measurements you want. Alot of people get strain gauge scales because they are cheaper then get upset because they were expecting it to perform like a magnetic force restoration scale. Unless you are willing to pay over $700 for a magnetic force restoration scale, expect to be working with the limitations of a strain guage scale.
Now how to test the linearity of your scale. Thats really easy. Find you and object like a paper clip or a small piece of stone or whatever. Set it on your scale and see how much it weighs and record the measurement. Take it off the scale and wait till the scale returns to zero. Then place the same object back and record the measurement. Do this a few times. You will notice after awhile how far off the measurements tend to be. The average of this error is your linearity. That's the margin of error you can confidently expect your scale to give you each time you weigh something. Comforting knowing that bit of information is now isnt it? Most manufacturers of milligram scales will advertise a linearity of +- .004g. Although, when you get a scale you might find the linearity to usually be +- .001g or +- .002g. Thats because they dont want to be sued. They would rather err to the larger number and have you be happy to find that the scale performs "better than you expected" after you get it. If a manufacturer refuses to quote a linearity for a scale, find another product to buy.
Strain guage scales can have very good linearity. Dont doubt that just because its a cheap scale. But you have to take the tray off the scale each time you want to fine tune the mass of stuff you are weighing as I understand it anyway.
Another quality to be mindful of when buying a scale, is to check the readability of the scale. I understand what that means but can't describe it well. So here's an example. On milligram scales you will usually find a readability of .001g or .002g. This means that the number in the window will move in increments of .001g or .002g or what ever the readability is engineered to be. Obviously, most of us will want a readability of .001g.
After all this talk, what scales do I have? I first got myself a Diamond Professional-Mini for $10. Max weigh capacity 10g and the manufacturer doesnt advertise a linearity for it whoever the manufacturer is. After testing it myself, I would say the worst linearity it will give is +-.004g on average. But a linearity of +-.003g is typical. The more I try to weigh at one time the worse the linearity is. I find that the best linearity is between .020g and 1g. After a year, I decided to invest in something I could trust better and read up on milligram scales to learn everything I could within reason and settled on a Gempro-250 for about $150 and it comes with a limited lifetime warranty (sweet!). It has a max weigh capacity of 50g and an advertised linearity of +-.001g. After testing it on my own, I find that the typical linearity is indeed about +-.001g and at worst +-.003g usualy. But it is a bit quirky when using calibration weights and placing the windscreen down. I havent figured it out yet but lowering the wind screen when I have a calibration weight on it makes the scale give a lower measurement. But it only does that with the heavy calibration weights. Otherwise, I think its a very good scale. I find that my scales will disagree by upto .005g obviously because the diamond has a greater linearity but usually the disagreement is only .003g or less. Neither scale can accurately weigh anything less than .005g and its not reasonable to expect any scale to imho.
I hope this helps people to understand why their scales dont work the way they think their scales should and to understand how to properly use their scales to get a measurement they can be confident with. Getting a weight measurement that you can be confident with is very important if one is to use substances safely. Obviously if you are dosing stuff thats active at less than .005g, you should be using volumetric dosing or pay a couple thousand for a truely bad assed scale worthy of doing some science with.
From what Ive read about digital scales, linearity is a quality that one really wants to consider when buying a scale as well as what sort of load cell technology the scale has. The load cell has a lot to do with the price and performance/engineering of a scale. The linearity tells you how accurately the scale will measure the wieght of a mass each time you put it on the scale- margin of error of each measurement. Notice that I am using the terms accuracy and performance to mean different things. Accuracy means how well it works and performance means how it can be expected to function.
Reality check: Alot of people get upset with the scale they bought because they dont understand how it is engineered to perform. Here's a great video on this subject that better explains what I mean:
hxxp://www.youtube.com/watch?feature=player_embedded&v=89BOlViQXto
From watching the video, you quickly understand why some people get upset with their high dollar scale they bought, that uses strain gauge technology, because it won't register changes in the weight when the user is slowly adding small amounts of some powder. The video demonstrates that. Obviously, the problem isnt the lack of sensitivity of the scale but rather the way the software of the scale was engineered to perform and is well explained in the video.
What this video doesnt tell you is how to add small amounts of stuff to what you are trying to weigh, when using a strain gauge scale, and get a new measurement instead of having the thing sit there and register no changes, which is what a lot of people bitch about. What I have found to work is to remove the weighing tray holding your stuff from your scale. Then add a small amount of stuff to the mass on the tray. Then return the tray to the scale to see how much you just added. If you still dont have the measurement you want, remove the tray, add or remove some stuff to/from the tray. Then replace the tray on the scale to see what you've got and so on. You get my point: remove the tray from the scale before adding or removing stuff to finely adjust your total mass, then return the tray to the scale to get a new measurement. Practice this with some salt or sugar or tea leaves as they did in the video. With a little playing around with your scale you should get an idea of how to use it to reliably to get the measurements you want. Alot of people get strain gauge scales because they are cheaper then get upset because they were expecting it to perform like a magnetic force restoration scale. Unless you are willing to pay over $700 for a magnetic force restoration scale, expect to be working with the limitations of a strain guage scale.
Now how to test the linearity of your scale. Thats really easy. Find you and object like a paper clip or a small piece of stone or whatever. Set it on your scale and see how much it weighs and record the measurement. Take it off the scale and wait till the scale returns to zero. Then place the same object back and record the measurement. Do this a few times. You will notice after awhile how far off the measurements tend to be. The average of this error is your linearity. That's the margin of error you can confidently expect your scale to give you each time you weigh something. Comforting knowing that bit of information is now isnt it? Most manufacturers of milligram scales will advertise a linearity of +- .004g. Although, when you get a scale you might find the linearity to usually be +- .001g or +- .002g. Thats because they dont want to be sued. They would rather err to the larger number and have you be happy to find that the scale performs "better than you expected" after you get it. If a manufacturer refuses to quote a linearity for a scale, find another product to buy.
Strain guage scales can have very good linearity. Dont doubt that just because its a cheap scale. But you have to take the tray off the scale each time you want to fine tune the mass of stuff you are weighing as I understand it anyway.
Another quality to be mindful of when buying a scale, is to check the readability of the scale. I understand what that means but can't describe it well. So here's an example. On milligram scales you will usually find a readability of .001g or .002g. This means that the number in the window will move in increments of .001g or .002g or what ever the readability is engineered to be. Obviously, most of us will want a readability of .001g.
After all this talk, what scales do I have? I first got myself a Diamond Professional-Mini for $10. Max weigh capacity 10g and the manufacturer doesnt advertise a linearity for it whoever the manufacturer is. After testing it myself, I would say the worst linearity it will give is +-.004g on average. But a linearity of +-.003g is typical. The more I try to weigh at one time the worse the linearity is. I find that the best linearity is between .020g and 1g. After a year, I decided to invest in something I could trust better and read up on milligram scales to learn everything I could within reason and settled on a Gempro-250 for about $150 and it comes with a limited lifetime warranty (sweet!). It has a max weigh capacity of 50g and an advertised linearity of +-.001g. After testing it on my own, I find that the typical linearity is indeed about +-.001g and at worst +-.003g usualy. But it is a bit quirky when using calibration weights and placing the windscreen down. I havent figured it out yet but lowering the wind screen when I have a calibration weight on it makes the scale give a lower measurement. But it only does that with the heavy calibration weights. Otherwise, I think its a very good scale. I find that my scales will disagree by upto .005g obviously because the diamond has a greater linearity but usually the disagreement is only .003g or less. Neither scale can accurately weigh anything less than .005g and its not reasonable to expect any scale to imho.
I hope this helps people to understand why their scales dont work the way they think their scales should and to understand how to properly use their scales to get a measurement they can be confident with. Getting a weight measurement that you can be confident with is very important if one is to use substances safely. Obviously if you are dosing stuff thats active at less than .005g, you should be using volumetric dosing or pay a couple thousand for a truely bad assed scale worthy of doing some science with.
Last edited:
the toad
Bluelighter
Very nice post @moss on a rock... I've used very high quality balances in chemistry labs in college but never felt the need for anything more than a cheapo mg version... I purchsed a set of calibration weights and they find the readout matches their designations quite well... perhaps 3mg variances at most with the larger masses...
I find that I can "pour" add to my cheapo as long as I keep the flow continuous and steady until right at the mark and stop only once...
Thanks for the info
I find that I can "pour" add to my cheapo as long as I keep the flow continuous and steady until right at the mark and stop only once...
Thanks for the info
Had a question about this particular scale;
http://www.oldwillknottscales.com/jennings-jscale-jsvg40.html
The price and style attract me, the site selling it claims its very accurate but I wanted to get a second opinion. Anyone have experience with this series from Jennings scales?
http://www.oldwillknottscales.com/jennings-jscale-jsvg40.html
The price and style attract me, the site selling it claims its very accurate but I wanted to get a second opinion. Anyone have experience with this series from Jennings scales?
sn23
Bluelighter
- Joined
- Dec 31, 2010
- Messages
- 239
Very good and informative post, Moss on a stone, thank you!
You may want to look into buoyancy-related phenomena, as the geometry of the weighed object and the dynamics of the air flow surrounding it can have a measurable impact on the registered weight (if the scale is sensitive enough). That could be the culprit with the windscreen, I'd suppose.
You may want to look into buoyancy-related phenomena, as the geometry of the weighed object and the dynamics of the air flow surrounding it can have a measurable impact on the registered weight (if the scale is sensitive enough). That could be the culprit with the windscreen, I'd suppose.
the toad
Bluelighter
I do not have personal experience with that scale however I would like to offer my opinion on the matter...
For the price that doesn't seem all that great to me... I got my gemini-20 for about half the cost of that one shipping included from amazon... and works as well as I would expect a 100 dollar one to...
Also in looking at the specs I noticed specs listed only incarats and not milligrams... I'm sure it does weigh metricly but its readability figures are unpublished as I could see...
And lastly, I wouldn't buy a balance from a company called "Old will knott scales"
"Old, will not scale"
Moss on a rock
Greenlighter
- Joined
- Feb 15, 2011
- Messages
- 4
Thanks for the feedback yall. I admit my info is just what I understand regarding this very technical topic and admit its possible I could be talking out my ass.
Chemically Insane: I agree. After getting my Gempro-250 and comparing it to the $10 el cheapo I had, Im quite impressed with the el cheapo's linearity. As you found with yours its off by 3mg typically. Its not great but thats really not bad.
BTW: I figured out the deal with the windscreen. Its static electricity buggerin up the works. I put some dry peppermint leaves in the expansion tray. Lowered the windscreen and then rubbed my finger tip all over the top of the windscreen. Almost instantly, leaves were jumping up off the expansion tray and sticking to the underside of the windscreen. Bad, very bad....
Im going to ask the retailer and manufacturer (if I have to) to see what can be done about it. Until then, I'll be holding my breath when taking measurements. Its pretty easy to tell if wind currents are buggerin up your measurements. Either the number stays the same or its moving all over the place.
Quasimodo, did you read my post above? It points out the important info to look for when buying a scale imho. If you can't get that info from the retailer, find another scale to buy or buy from another retailer. I bought my scale from these guys: hxxp://balance.balances.com/scales/9
Look at how they list the specs on their scales. They even include videos on using the scales, comparing the scales to other scales, and even rip apart the scales and show you pics of the inards of the scales. Who else goes to that much trouble to gain your confidence in their products? Im not trying to encourage you to buy from them but I like how they present their products. Thats why I bought from them and I encourage you to check them out.
Chemically Insane: I agree. After getting my Gempro-250 and comparing it to the $10 el cheapo I had, Im quite impressed with the el cheapo's linearity. As you found with yours its off by 3mg typically. Its not great but thats really not bad.
BTW: I figured out the deal with the windscreen. Its static electricity buggerin up the works. I put some dry peppermint leaves in the expansion tray. Lowered the windscreen and then rubbed my finger tip all over the top of the windscreen. Almost instantly, leaves were jumping up off the expansion tray and sticking to the underside of the windscreen. Bad, very bad....
Im going to ask the retailer and manufacturer (if I have to) to see what can be done about it. Until then, I'll be holding my breath when taking measurements. Its pretty easy to tell if wind currents are buggerin up your measurements. Either the number stays the same or its moving all over the place.
Quasimodo, did you read my post above? It points out the important info to look for when buying a scale imho. If you can't get that info from the retailer, find another scale to buy or buy from another retailer. I bought my scale from these guys: hxxp://balance.balances.com/scales/9
Look at how they list the specs on their scales. They even include videos on using the scales, comparing the scales to other scales, and even rip apart the scales and show you pics of the inards of the scales. Who else goes to that much trouble to gain your confidence in their products? Im not trying to encourage you to buy from them but I like how they present their products. Thats why I bought from them and I encourage you to check them out.
the toad
Bluelighter
You could try wiping off the windscreen with a soft cloth and some white vinegar or lemon juice then water... sometimes its a contaminate dust or film causing ionization... vinegar is good at removing this sort of thing...
biffhenderson
Bluelighter
Forgive me if this has been already answered but I've been scrolling through this tread for awhile.
I've decided to buy the Sartorius AY123 50 X .001 and learn how to do this right. Holy cow these calibration weights are expensive and confusing with all these classes I don't understand. Can someone slip me a cheat sheet of what calibration weights I need. I can spend what is needed but I don't like to waste money.
Edit: It comes with a 50 gram calibration weight. Do I need the little ones like a 1 gram or 10 gram calibration weights to get accurate results?
I've decided to buy the Sartorius AY123 50 X .001 and learn how to do this right. Holy cow these calibration weights are expensive and confusing with all these classes I don't understand. Can someone slip me a cheat sheet of what calibration weights I need. I can spend what is needed but I don't like to waste money.
Edit: It comes with a 50 gram calibration weight. Do I need the little ones like a 1 gram or 10 gram calibration weights to get accurate results?
Last edited:
the toad
Bluelighter
There should be instructions included... if it comes with a calibration weight then you dont need to buy any more...