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Discussion => Drug safety => Topic started by: sl1pknot on July 09, 2012, 12:10 am

Title: Which scale do you trust to accurately measure out 1 milligram?
Post by: sl1pknot on July 09, 2012, 12:10 am
I currently have an ammunition scale but it is only accurate to +/- 5mg. A scale such as this would be terribly inaccurate and possibly very dangerous at measuring out 1/2 milligram  doses of drugs such as the NBOMes, alprazolam, etc.

I would like to invest in a quality scale that's accurate to +/- a milligram or so.

The Gemeni 20 on Amazon just seems... too cheap? In my experience with equipment like this, you get what you pay for... The reviews look good but I feel like this thing would break in a week or two:  http://www.amazon.com/American-Weigh-Gemini-20-Portable-Milligram/dp/B0012TDNAM/ref=sr_1_1?s=home-garden&ie=UTF8&qid=1341792316&sr=1-1&keywords=milligram+scale

I would think I could trust this one more because it seems a bit nicer, however the reviews don't seem so great... Is the price difference seriously because it can weigh 50g rather than 20?
http://www.amazon.com/American-Weigh-Minipro-50-Compact-Precision/dp/B002SVOXHK/ref=sr_1_7?s=home-garden&ie=UTF8&qid=1341792316&sr=1-7&keywords=milligram+scale

It would be much appreciated if somebody could help point me in the right direction or share their thoughts/experiences.

Thanks,
Sl1pknot
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: ilovelsd69 on July 09, 2012, 12:43 am
scales like the ones you're looking for typically cost $1,500+ and come with their own very heavy weighing table

The gemini 20 should be enough for Nbome and must RC i think, No?
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: sl1pknot on July 09, 2012, 12:51 am
The gemini 20 should be enough for Nbome and must RC i think, No?
This is what I have heard about the 20 and the 50, however because of their low prices I just wanted to get some opinions/experiences from other members.

By the way the quote under your username is one of my favorites. Thompson FTW.
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: ilovelsd69 on July 09, 2012, 12:55 am
1500-2000 $ is a lot of money for a scale, i don't think RC vendors there own such a scale .. but i can be wrong of course..
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: ilovelsd69 on July 09, 2012, 12:58 am
There the specs of the Gemini 20:

    6 different weighing modes

    Tare’ button – weigh items in a container – the tare button will subtract the container weight from the total reading

    Spacious weighing platform

    Backlit LCD screen

    3 minute auto power off saves battery life

    Low battery alarm

    Cover and pouch protect scales when not in use

    Maximum weight: 20g/0.001g, 0.7055oz/0.0001oz, 100.00ct/0.005ct, 0.6430ozt/0.0001ozt, 12.860dwt/0.001dwt,

    308.65gn/0.001gn

    Display: 5 digit blue backlit LCD

    Auto power off: 3 minutes

    Operating temperature: 10 - 30°C

    Scale dimensions: 9 x 10 x 3cm (3.5 x 4 x 1.2 ”)

    Screen dimensions: 3.2 x 2.2cm (1.2 x 0.5 ”)

    Weighing platform diameter: 2cm (0.7")

    Powered by: 2 X AAA batteries ( Not included )
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: ilovelsd69 on July 09, 2012, 01:02 am
Doses of 25i can be weighted with that i mean 1000 micrograms = 1 milligram, No ?
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: MasterS on July 09, 2012, 01:09 am
I own the made in china AWS brand DIA-20. I've found it to be very consistent so far to +/- 2mg. I can take an item weigh it, write down the measurement, weight a bunch of things and do the same, then go back to the item it always weighs the same. However in a different instance the same items may be a couple mg's different but still consistant in the same weighing session. $25 mg scale, I honestly cannot complain in the slightest. I own Tanita scales which rock and this one weighs the same on my .01 Tanita scale of course I can't tell the difference in the .001 level but I've been very happy. When weighing things smaller than 5mg you'll need a magnifier if you want to split a 4mg crystal in half by powdering it and cutting with a razor
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: ilovelsd69 on July 09, 2012, 01:12 am
I own the made in china AWS brand DIA-20. I've found it to be very consistent so far to +/- 2mg. I can take an item weigh it, write down the measurement, weight a bunch of things and do the same, then go back to the item it always weighs the same. However in a different instance the same items may be a couple mg's different but still consistant in the same weighing session. $25 mg scale, I honestly cannot complain in the slightest. I own Tanita scales which rock and this one weighs the same on my .01 Tanita scale of course I can't tell the difference in the .001 level but I've been very happy. When weighing things smaller than 5mg you'll need a magnifier if you want to split a 4mg crystal in half by powdering it and cutting with a razor

Do you really think you're brain will make a difference between a 1000 microgram or a 990, 980 microgram dose ???
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: opi on July 09, 2012, 01:15 am
the issue comes to how accurate the scale is.. for all you know it has an error of +- 1mg or it could be +- 10mg which would be a HUGE difference..

I think your best bet would be to make an solution and make sure you mix it very very well and just use a oral syringe to dose with accuracy.  So you could make it so 1 ml = 1 mg. So dissolve 10 mg of powder into 10 ml of solution so you just measure up a ml into the syringe and dose. But before you take your dose out of the bottle make sure you mix the solution very well so its evenly dissolved and there are no 'hot spots'.
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: ilovelsd69 on July 09, 2012, 01:20 am
the issue comes to how accurate the scale is.. for all you know it has an error of +- 1mg or it could be +- 10mg which would be a HUGE difference..

I think your best bet would be to make an solution and make sure you mix it very very well and just use a oral syringe to dose with accuracy.  So you could make it so 1 ml = 1 mg. So dissolve 10 mg of powder into 10 ml of solution so you just measure up a ml into the syringe and dose. But before you take your dose out of the bottle make sure you mix the solution very well so its evenly dissolved and there are no 'hot spots'.

How you would lay that on blotters without a syringe?
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: Ben on July 09, 2012, 01:21 am
Interesting update on this: I recently got to play with a very inexpensive balance, for sale here:

http://www.dealextreme.com/p/digital-precision-scale-20g-max-0-001g-resolution-10515

It only costs $22, but testing it with reference weights it proved to be extremely acccurate for that price. The error measuring a 10 gram reference weight was about 0.1%. For a proper analytical balance that might not be considered top notch, for for something available at that price, its surprisingly good.

I've only tested one single specimen of these scales however, so i cannot judge if some may be off. The order does include a reference weight of its own though. It is supposed to weigh 10 grans, and i could not determine its deviation from that down to the milligram using other scales.
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: ilovelsd69 on July 09, 2012, 01:22 am
Interesting update on this: I recently got to play with a very inexpensive balance, for sale here:

http://www.dealextreme.com/p/digital-precision-scale-20g-max-0-001g-resolution-10515

It only costs $22, but testing it with reference weights it proved to be extremely acccurate for that price. The error measuring a 10 gram reference weight was about 0.1%. For a proper analytical balance that might not be considered top notch, for for something available at that price, its surprisingly good.

I've only tested one single specimen of these scales however, so i cannot judge if some may be off. The order does include a reference weight of its own though. It is supposed to weigh 10 grans, and i could not determine its deviation from that down to the milligram using other scales.

This is exactly the scale we are talking about ..
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: ilovelsd69 on July 09, 2012, 01:24 am
http://www.ebay.ca/itm/New-20g-x-0-001g-AMW-Gemini-Digital-Milligram-Gram-Pocket-Scale-Balance-Weight-/261054504550?pt=US_Pocket_Digital_Scales&hash=item3cc80f9e66
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: opi on July 09, 2012, 01:29 am
haha I just orderd that one from ebay for 16$ straight outta china!
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: ilovelsd69 on July 09, 2012, 01:30 am
haha I just orderd that one from ebay for 16$ straight outta china!

ordered the same too  ;)
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: Ben on July 09, 2012, 01:38 am
I suppose its available through many channels...

I only have experience with one single unit, and that proved to be very good. I have no idea how they manage to produce it at this price, nor if all of them are equally accurate, but based on the single experience i'm amazed by how accurate it is.
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: ilovelsd69 on July 09, 2012, 01:41 am
I suppose its available through many channels...

I only have experience with one single unit, and that proved to be very good. I have no idea how they manage to produce it at this price, nor if all of them are equally accurate, but based on the single experience i'm amazed by how accurate it is.

There is another thread on this forum saying this model was good enough for 25i, i just can't find it now, i'm too sleepy right now ... my brain has not had sleep for 36 hours..
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: sl1pknot on July 09, 2012, 06:31 am
Maybe that was this thread:
http://dkn255hz262ypmii.onion/index.php?topic=27356.msg296860;boardseen#new

Someone from that thread also pointed this scale out: http://www.amazon.com/My-Weigh-GemPro-250-Compact/dp/B004C3I3AA

Ben, what were you weighing out with that scale?

As I said I would like to be able to accurately measure out 25I-NBOMe doses and Alprazolam doses from powder, but much over $200 is a bit more than I'm willing to spend.

I suppose I could also do the dilution method and use gelcaps, but I would rather avoid this... although if it comes down to it maybe that is safest. I don't want to be giving anyone what they think is a reasonable dose of alprazolam and have them pass out like a rock in 30 minutes.

Opinions/Input?

Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: stolea2269 on July 09, 2012, 06:42 am
Having owned that scale and having recently upgraded to a new one, I suppose I'll offer my thoughts on it.

I wasn't happy with it - you can definitely tell that it's a $20 scale. While it served it's purpose fairly well, it just felt cheap and I was always doubting the numbers it displayed. I measured things mostly in the 18-32mg range, and the 120-200mg range. It worked exponentially more well at the higher. To be completely honest, I wouldn't feel comfortable measuring anything sub-10mg and even that would be pushing it. Hell, the scale rarely actually showed that there was anything in the weigh pan until it exceeded 5 or 6 mg. Sometimes an 18mg dose would weigh 20mg or 22mg on the next read, which is fine for the 2c-x chemicals or any 4-sub tryps, but can be a life/death situation with the NBOMe family.

If you're laying it on blotters, my guess (and sorry to make assumptions :P, correct me if I'm wrong!) is that you're going to be selling them? Or dealing with large quantities? Go for a nice scale. You won't regret it, and your customers will be happy. You'll make up the extra $$ in time saved fiddling around with this cheap little thing and in confidence in the doses you've weighed out.

The only other feasible option is to, like another member said, weigh out a large quantity and dilute it. But that's really only viable for personal use.

If you have any more questions about that scale, just let me know!! I'll do my best to help you however I can!
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: sl1pknot on July 09, 2012, 03:46 pm
Having owned that scale and having recently upgraded to a new one, I suppose I'll offer my thoughts on it.

I wasn't happy with it - you can definitely tell that it's a $20 scale. While it served it's purpose fairly well, it just felt cheap and I was always doubting the numbers it displayed. I measured things mostly in the 18-32mg range, and the 120-200mg range. It worked exponentially more well at the higher. To be completely honest, I wouldn't feel comfortable measuring anything sub-10mg and even that would be pushing it. Hell, the scale rarely actually showed that there was anything in the weigh pan until it exceeded 5 or 6 mg. Sometimes an 18mg dose would weigh 20mg or 22mg on the next read, which is fine for the 2c-x chemicals or any 4-sub tryps, but can be a life/death situation with the NBOMe family.

If you're laying it on blotters, my guess (and sorry to make assumptions :P, correct me if I'm wrong!) is that you're going to be selling them? Or dealing with large quantities? Go for a nice scale. You won't regret it, and your customers will be happy. You'll make up the extra $$ in time saved fiddling around with this cheap little thing and in confidence in the doses you've weighed out.

The only other feasible option is to, like another member said, weigh out a large quantity and dilute it. But that's really only viable for personal use.

If you have any more questions about that scale, just let me know!! I'll do my best to help you however I can!
+1 Thanks! -Oops, seems I have to wait a bit to give karma.-  Which scale did you upgrade to? I think you're right, I'll probably save a bit more money and invest in a better quality one, I don't want to be putting anyone in danger.
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: stolea2269 on July 09, 2012, 03:50 pm
Having owned that scale and having recently upgraded to a new one, I suppose I'll offer my thoughts on it.

I wasn't happy with it - you can definitely tell that it's a $20 scale. While it served it's purpose fairly well, it just felt cheap and I was always doubting the numbers it displayed. I measured things mostly in the 18-32mg range, and the 120-200mg range. It worked exponentially more well at the higher. To be completely honest, I wouldn't feel comfortable measuring anything sub-10mg and even that would be pushing it. Hell, the scale rarely actually showed that there was anything in the weigh pan until it exceeded 5 or 6 mg. Sometimes an 18mg dose would weigh 20mg or 22mg on the next read, which is fine for the 2c-x chemicals or any 4-sub tryps, but can be a life/death situation with the NBOMe family.

If you're laying it on blotters, my guess (and sorry to make assumptions :P, correct me if I'm wrong!) is that you're going to be selling them? Or dealing with large quantities? Go for a nice scale. You won't regret it, and your customers will be happy. You'll make up the extra $$ in time saved fiddling around with this cheap little thing and in confidence in the doses you've weighed out.

The only other feasible option is to, like another member said, weigh out a large quantity and dilute it. But that's really only viable for personal use.

If you have any more questions about that scale, just let me know!! I'll do my best to help you however I can!
+1 Thanks! -Oops, seems I have to wait a bit to give karma.-  Which scale did you upgrade to? I think you're right, I'll probably save a bit more money and invest in a better quality one, I don't want to be putting anyone in danger.

Ahaha, I appreciate the thought mate.

Let me go find a link, one sec...

http://www.amazon.com/American-Weigh-GPR-20-Gemini-PRO-Milligram/dp/B003STEJD4/ref=sr_1_2?s=home-garden&ie=UTF8&qid=1341848959&sr=1-2&keywords=mg+scale

^That's the one I went with. While it still isn't lab-grade, it's a huge improvement over the other one. It feels solid, things weigh accurately, and I have a lot more faith in my measurements!
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: Delta11 on July 09, 2012, 06:04 pm
Having owned that scale and having recently upgraded to a new one, I suppose I'll offer my thoughts on it.

I wasn't happy with it - you can definitely tell that it's a $20 scale. While it served it's purpose fairly well, it just felt cheap and I was always doubting the numbers it displayed. I measured things mostly in the 18-32mg range, and the 120-200mg range. It worked exponentially more well at the higher. To be completely honest, I wouldn't feel comfortable measuring anything sub-10mg and even that would be pushing it. Hell, the scale rarely actually showed that there was anything in the weigh pan until it exceeded 5 or 6 mg. Sometimes an 18mg dose would weigh 20mg or 22mg on the next read, which is fine for the 2c-x chemicals or any 4-sub tryps, but can be a life/death situation with the NBOMe family.

If you're laying it on blotters, my guess (and sorry to make assumptions :P, correct me if I'm wrong!) is that you're going to be selling them? Or dealing with large quantities? Go for a nice scale. You won't regret it, and your customers will be happy. You'll make up the extra $$ in time saved fiddling around with this cheap little thing and in confidence in the doses you've weighed out.

The only other feasible option is to, like another member said, weigh out a large quantity and dilute it. But that's really only viable for personal use.

If you have any more questions about that scale, just let me know!! I'll do my best to help you however I can!
+1 Thanks! -Oops, seems I have to wait a bit to give karma.-  Which scale did you upgrade to? I think you're right, I'll probably save a bit more money and invest in a better quality one, I don't want to be putting anyone in danger.

Ahaha, I appreciate the thought mate.

Let me go find a link, one sec...

http://www.amazon.com/American-Weigh-GPR-20-Gemini-PRO-Milligram/dp/B003STEJD4/ref=sr_1_2?s=home-garden&ie=UTF8&qid=1341848959&sr=1-2&keywords=mg+scale

^That's the one I went with. While it still isn't lab-grade, it's a huge improvement over the other one. It feels solid, things weigh accurately, and I have a lot more faith in my measurements!
I have the same scale and it's pretty accurate, a method to measure RC's more accurately is to weigh out a gel cap and to scoop up your powder using the gelcap and then subtract the initial weight until you hit your desired weight.
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: ilovelsd69 on July 09, 2012, 11:08 pm

Ahaha, I appreciate the thought mate.

Let me go find a link, one sec...

http://www.amazon.com/American-Weigh-GPR-20-Gemini-PRO-Milligram/dp/B003STEJD4/ref=sr_1_2?s=home-garden&ie=UTF8&qid=1341848959&sr=1-2&keywords=mg+scale

^That's the one I went with. While it still isn't lab-grade, it's a huge improvement over the other one. It feels solid, things weigh accurately, and I have a lot more faith in my measurements!

Thanks, i have by mistake mixed the two models :o Strangely on eBay (CA) or Amazon (CA) he sold it 140-170 $ and on amazon (US) they sold it at 68.95 $, considering i will pay customs fee of maybe 20-30 $ it is still cheaper on amazon (US) lol
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: Prawl42 on July 09, 2012, 11:19 pm
your planning on measuring 25i on a scale that cost >$50?

please use volumetric measurements for this.


those kinds of scales are only just accurate enough for substances like 2c-b where +5/+10mg isnt a huge issue but still effects the trip some what.

Being 5mg out  on 25i is a whole different game.

volumetric is the way forward here.

i see there was already someone posting a short guide, if u require further assistance just ask!
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: Ben on July 10, 2012, 12:51 am
Maybe that was this thread:
http://dkn255hz262ypmii.onion/index.php?topic=27356.msg296860;boardseen#new

Someone from that thread also pointed this scale out: http://www.amazon.com/My-Weigh-GemPro-250-Compact/dp/B004C3I3AA

Ben, what were you weighing out with that scale?

As I said I would like to be able to accurately measure out 25I-NBOMe doses and Alprazolam doses from powder, but much over $200 is a bit more than I'm willing to spend.

I suppose I could also do the dilution method and use gelcaps, but I would rather avoid this... although if it comes down to it maybe that is safest. I don't want to be giving anyone what they think is a reasonable dose of alprazolam and have them pass out like a rock in 30 minutes.

Opinions/Input?

I tried a couple of things.

First of all, there was a reference weight included with the scale. I weighed that on a know-good scale, and it was accurate to 10.00 grams (10 mg resolution on that scale). On the scale from dealextreme it measured 10.011 grams, which is within 0.1%, more then is to be expected of most scales.

Another thing i tried to measure was a tablet with a design weight of 60 milligrams. Surely this measured 0.06 grams on the reference scale, but it had no further resolution. On the dealextreme scale this weighed in at 61 milligrams - very close to the expected value again.

The only further test i can do is bring the sacle to the university laboratory, set it up side by side with a calibrated professional one on a vibration-stabilized and perfectly level table, and compare the readings for objects of various weights between 10 mg and 20 grams. I'll try to do that whenever i have time and opportunity.

For now, i would conclude about the unit i studied:

- it is accurate to 1% or better
- its resolution is reliable apart from the variation of the last (1 mg) digit

I would not use these scales to measure out single amounts of <10 mg each, but if you wanted to measure out 50 mg of something, that measurement would be accurate within 10% of the displayed value. On 1 gram amounts the reading is accurate to better then 1%, easily outclassing any scales you can buy at your average big box store.

All this is based on the observation of one single unit however. Considering the idiotically low price i would not dare speculate that all of them perform this well. But provided the supplied calibration weights are all identical, you have a way of tell if yours is vastly off. If you have no reference you trust, i suggest verification by weighing coins. The 1 euro coin, for example, has a design weight of 7.5 grams. While this weight is not -that- reliable for a circulated coin, most of them actually do weigh between 7.4 and 7.6 grams, so measuring a couple is a good indication to tell if your scale is off by more then a few percent (i.e. defective).
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: gambino on July 10, 2012, 01:16 am
your planning on measuring 25i on a scale that cost >$50?

please use volumetric measurements for this.


those kinds of scales are only just accurate enough for substances like 2c-b where +5/+10mg isnt a huge issue but still effects the trip some what.

Being 5mg out  on 25i is a whole different game.

volumetric is the way forward here.

i see there was already someone posting a short guide, if u require further assistance just ask!

^this
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: Ben on July 10, 2012, 01:38 am
If you want to weigh and divide doses as snall as 1 mg each, i'd suggest dissolving the product, aliquotting it and then drying it again.

Measuring weight in the 1 mg range is very diffcult, and even analytical balances the price of  a car will not be that much help. These scales will not be any good telling 10 mg from  8 ir 12 mg. They were never designed to do that reliably, and nothing under $1000 used will.
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: ilovelsd69 on July 10, 2012, 01:44 am
Have you some examples guys of good volumetric scales for sale?
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: Prawl42 on July 10, 2012, 05:09 pm
Have you some examples guys of good volumetric scales for sale?

you dont get volumetric scales per se, its more the act of dissolving 10 mg of substance x in 20ml of liquid Y (water,acholol, a mix of the two)

then you will have 1mg of substance x for every 2ml of liquid or 500ug for every one ml.

Then you can buy some 1cc insulin syringes snap off the top or get some 1cc oral syringes and dose away!

you could allow a dose to dissolve to give you the substance back in powder form but you will lose some in the process.


But when doing this ALWAYS note down what you are doing step by step and label the shit out of everything there is nothing worse then dosing up what you think is 500ug of a substance from your solution bottle and finding out its really from your conc bottle!

I apologies for any typos/mistakes i am very tired!
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: Ben on July 11, 2012, 12:31 am
Making solutions is a good way to divide up substances you want in single milligram (or lower) quantities.

LSD blotters are a common example of this approach: weighing out the 0.1 mg quantities per dose required just isn't feasible, so people choose to dissolve a known amount and equally divide it over some paper resulting in a know concentration per square centimeter.

The solvent required depends on the substance being divided - methanol is generally a good choice if you're not all that sure. As the solvent is evaporated before the product is sold, it doenst matter if the solvent itself has undesired effects. Chloroform is also very good for more apolar drugs, and since it will all evaporate will pose no harm to the end user.
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: redalloverthelandguyhere on July 11, 2012, 12:42 am
ALWAYS calibrate the scales!

The cheap Chinese ones have this capability so if you buy a set of accurate weights of 50mg, 25mg, 10mg, 5mg and 2mg and 1mg weights, and if you calibrate and if the scales weigh accurate then its a winner.

I got a cheap set off a mate and they were labelled as 1mg accuracy but would not register powder until 5mg went on. That would be risky.

Tanita rock but the old sets were not designed to weigh anything less than 10mg increments. They were jewelry scales.

Later
Title: Re: Which scale do you trust to accurately measure out 1 milligram?
Post by: 00OOIlI00lO1O0 on July 11, 2012, 01:53 am
ALWAYS calibrate the scales!

The cheap Chinese ones have this capability so if you buy a set of accurate weights of 50mg, 25mg, 10mg, 5mg and 2mg and 1mg weights, and if you calibrate and if the scales weigh accurate then its a winner.

Quoted for truth.

Cheap scales are fine if their reviews check out okay, but always get a set of reference weights, which are usually rather cheap too. The scale could always be dropped, or not like being on an uneven surface. Every time you set up your scale, test it out with some of the reference weights to validate it and convince yourself of its accuracy.

Don't just depend on the 10g weights that they come with, that's not good enough for measuring in the milligram range.

Don't bother weighing less than 20mg of something, as they're not accurate enough at low weights.

As many have said, use a volumetric technique for dividing substances active at 10mg or less.  No scale is accurate enough for that.