Cheap mg scales any good? ($100)

[ISBN]

What is the opinion of low priced .001-.002g scales? Such as the </span>American Weigh DIA-10 Digital Carat Scale 50x0.01ct?



That same scale is also sold under different brand names (J Precision, and another I can't recall).



Has anyone had the opportunity to compare the accuracy of these scales
with others? They look a little bit iffy to me, but who knows.






Edited by: ISBN

[BlueMystic]

Don't know about that one, but the Gem-Pro 50 has had great accuracy for many without any problems.

[mattp]

look for Tanita gem scales on ebay. you will probably find one for
100ish. I have had problems with the Gem pro 50 and recently upgraded
to a tanita. with the gem pro, i would weigh 1 sample, reweigh it, and
get a difference of almost .1 g which can make a big difference
depending on what you are weighing out.

[HippieD9]

SWIM got a cheap one off e-bay, and it' surprisingly good! I've seen it under a few different names, so it may be the one you're thinking of.





Peace,


D.

[GDxCAT]

ive had too many problems with gem pro.

I never know how much im taking anymore. Its always + or - 5mg.

which, as stated earlier, is pretty dangerous depending on the substance.

[Metamountain]

Hey I have a Tanita which i got for like less than $100......amazing
for the price and totally accurate...the Japs know how to make
precision electronics..imho

[ISBN]

SWIM is going to go with a Tanita 1210-50. Those with the Tanita, was
it $100 on ebay? I've only seem them at $200 in the past few days.
Should I hold out for a deal, or is $200 just about the best I can get?





These harvested comments from alt.drugs.psychedelics helped me make up my mind
(even though they concern the GemPro, not the
DigiWeigh/Am.Weight/JPrecision/etc scales). Figure they'd help anyone in the same predicament:



"Seriously though, for the purposes of psychedelic drug dosage,

an $80 scale with claimed accuracy of +/- 1mg should not be used

to measure any amount smaller than 20mg."



"The only two milligram scales worth a damn which are affordable for the

average person would be the Tanita 1210 or the Acculab PP-2060D. Both are

around $250-350 depending where you buy them from. Both are accurate to

2mg and have 1mg readability."



"I wouldn't even think of using anything less than these for measuring

anything with a dosage under 100mg. If you cant afford one of these, use

volumetric liquid measurement technique. "



"gempro works, i've heard the tanita

1210 for $50 more is worth it. "



"Personally, I've seen the gempro 50

and the tanita 1210. The gempro is a pile, but it works OK. The tanita

is great. "</font>


Edited by: ISBN

[mariecurie]

A friend of mine has the precision which is a ten gram scale that
claims to be accurate to a milligram. I trust that thing to about five,
but if the wind switches from north to west it definitely drops a few
milligrams. Or goes up. Or turns off. Ad infinitum.

[ISBN]

I found this page from one of the cheapie manufacturers,
which describes some interesting tips for insuring scale accuracy. Among them:


"Please only operate and display scales at normal room temperature of 65
to 85 degrees Fahrenheit. If a scale is cold or hot, allow it to adjust
to normal room temperature for 12 hours if possible (this sounds
drastic but a load cell / sensor is like a metal sponge. &lt;span style="font-style: italic;"&gt;It takes many
hours for the temperature of the entire load cell to adjust&lt;/span&gt;. When a
scale is cold it can and will "drift". This is when a scale starts
increasing or decreasing its displayed number (0.1g, 0.2g, 0.3g, etc)."

"HERE'S A TEST: Turn on your scale and place a weight on it. Then call
a friend on your cell phone and hold the phone near the scale. The
display on the scale will change dramatically as it picks up the radio
signal from your phone. This happens to every brand electronic scale to
different degrees depending on design. Scales will pick up this
interference from up to 15 feet away! &lt;span style="font-style: italic;"&gt;Do not operate a cell or cordless phone within 10 feet of an in-use scale!&lt;/span&gt;"

"Low Batteries, bad battery connections & Faulty AC Adaptors are
the #1 cause of scale malfunction and inaccuracy...Please replace the
batteries often (and only use good quality batteries)...Please test
your scale with a good set of batteries (instead of the AC adaptor) to
determine if perhaps the AC adaptor is faulty."

"I hope you understand the importance of calibrating and operating in a
stable, vibration and interference free environment. We just can't
stress it enough."

Edited by: Micklemouse

[yajw]

A balance is an investment. For myself, a balance gets used for a
number of purposes, and accuracy and repeatibility are extremely
important. I had 3 gempro-50, and none of them were worth a damn. The
tanita line seem to be enjoyed by a number of people, as well as the
acculab series. But for around the same price (or a little more), you
can get a 1mg or 1mcg scale off ebay, lab-x or from a number of
university surplus auction sites. The majority are due to equipment
upgrading, and the scales are kept in good condition. I acquired an
electronic, internal calibration microgram scale for $200. It could
probably use a servicing, but checking with calibration weights allowed
me to see the small discrepancy, and allow for that.

[DrugPhreak]

For gram scales you can see how accurate they are by placing a US nickel on the scale… if it shows 5gm than it’s accurate (it's also easy to remember... 5 cents weighs 5 grams). There's no need to buy any of those weights to test it. When it comes to cheap milligram scales the less they are capable of weighing the more accurate they will be.

[moeBius]

i can only recommend to take a look at ebay for second hand analog lab-scales.

i found really good mettler and satorius scales there for less than 70€.

with a little search you get a calibrated scale, weighting precisely from 0.1mg to 100g.

but keep in mind that you have to transport it, it's defenitely a bad idea to do this via the post.

[Dualpower]

Apparently Tanita's have been subject to a lot of knock offs and forgerys. What you pay is what you get.



For those who had accuracy problems with the gem pros, did you use it
properly? Have you ever dropped it? Were you using it beside an
electromagnetic field?



Honestly most people probably don't take care of their scales properly,
if it can measure .002g its damn easy to break without even noticing.

[yajw]

Originally Posted by Dualpower

For those who had accuracy problems with the gem pros, did you use it
properly? Have you ever dropped it? Were you using it beside an
electromagnetic field?

Yes. No. No.



The first was defective and there was no consistency in readings.
Multiple battery changes were tried. The manufacturers replacement
would attempt to calibrate, then seem to lose the calibration inbetween
weighings. This presented a problem with one experiment, yet luckily
the compund was forgiving. Always used on a vibration dampener pad, it
a concrete floored room. While it is supposedly a 2mg capable scale, it
had a range of +/- 2mg. Far too much allowance for my personal taste.
These scales are great for weighing out a large mass of compounds that
can be dissoled into a known concentration for testing. But for
individual or repeated small measurements, they are more trouble than
they're worth. YMMV



I use my balance for a number of things and like precision and
accuracy. Luckily those university years provided a nice set of
calibration weights that sit around.

[ISBN]

Originally Posted by DrugPhreak

For gram scales you can see how accurate they are by placing a US
nickel on the scale… if it shows 5gm than it’s accurate (it's also easy
to remember... 5 cents weighs 5 grams). There's no need to buy any of
those weights to test it. When it comes to cheap milligram scales the
less they are capable of weighing the more accurate they will be.

Good idea, but I'd like to note the mass of coins fluctuates with
their age and condition quite a bit. While a perfectly produced, brand
new 2005 nickel should weigh 5 grams, it may not. I wouldn't rely on
using just one nickel to judge a scale. Using an array of brand new,
clean, nickels to find an average would seem to be a better route.




Another way to judge accuracy at a lighter mass would be to measure
a prescription pill, which are also produced under strict control.
e.g., a 10mg Claritin will weigh out to 100mg (fillers). While it may
be hard to find out the mass the pill should be, they usually adhere to
common increments (so if a pill weighs out to 97mg...it's probably
supposed to weigh out to 100mg). But, this has the same problems of the
above mentioned method. The pills may vary +/-2mg.




All calibration weights are not created equal.

ASTM
Class 0: used as primary reference
standards for calibrating other reference
standards and weights. </font>
<ul>[*]UltraClass:
Available exclusively from [proprietor]
. Developed to meet the most demanding
calibration needs with the ability to
be adjusted - avoiding the costly replacement
issues of one piece weights. UltraClass
weight tolerances are 40-50% better
than ANSI/ASTM E617 Class 1 and are
equal to or exceed OIML R 111 Class
E2 standards. UltraClass weights and
weight sets are available in a full
range of weight denominations </font>[*]ASTM
Class 1: Can be used as a reference
standard in calibrating other weights
and is appropriate for calibrating high
precision analytical balances with a
readability as low as 0.1mg to 0.01mg.
</font>[*] ASTM
Class 2: Appropriate for calibrating
high-precision top loading balances
with a readability as low as 0.01g to
0.001g.</font>[*] ASTM
Class 3: Appropriate for calibrating
balances with moderate precision, with
a readability as low as 0.1g to 0.01g.</font>[*]ASTM
Class 4 -For calibration of semi-analytical
balances and for student use. </font>[*]NIST Class
F - primarily used to test commercial weighing devices by
state and local weights and measures officials, device installers
and service technicians. Class F weights may be used to test most
accuracy class III scales, all scales of class III L or IIII,
and scales not marked with a class designation. Calibrated according
to NIST Handbook 105-1</font>[*]OIML
Class E1 - Used as primary reference
standards for calibrating other reference
standards and weights. </font>[*]OIML
Class E2 - Can be used as a reference
standard in calibrating other weights
and is appropriate for calibrating high
precision analytical balances with a
readability as low as 0.1mg to 0.01mg.
</font>[*]OIML
Class F1 - Appropriate for calibrating
high-precision toploading balances with
a readability as low as 0.01g to 0.001g.</font>[*]OIML
Class F2 - For calibration of semi-analytical
balances and for student use. </font>[*]OIML
Class M1, M2, M3 - Economical
Weights for general laboratory, industrial,
commercial, technical and educational
use. Typically fabricated from cast
iron or brass. Class M2 commonly used
for student brass weights. </font>

</font>[/list]

Does anyone have any tips or tricks for handling RC's?</font>
SWIM got his scale today and has been practicing measuring and filling
with broken up aspirin. He's hoping there is some magical method
because he has really poor fine motor control. He tried breaking up on
a smallish square of paper, folding it in half, and pouring onto the
weighing platform. What a mess he made. Anyone have any ideas of what
he could use as a little spoon?




update: Thanks nagonog. </span>He built off of your ways. Basically, it's a little tripod
funnel setup that hovers over an open gelcap. The overly detailed
description: The gelcap is help upward by taking a 5cm X 1cm portion of
the sticky side of a post-it note. The cap is placed in the middle of
this strip, and the strip is folded closed. So, imagine a coffee mug
without a bottom, and with a long flat handle extension. Then he made a
funnel with a rather steep slope (like, 5cm tall, 2cm diameter at the
top). The funnel is made from glassine paper (a smooth paper that is
sometimes sold as "powder paper" to pharmacists. He found it from an
old glassine envelope/bag that held some natural artists' charcoal
sticks he bought a while ago. Glassine paper is commonly used for
dainty invitiation/stationary enelopes. It is slightly transparent). He
then made a non-clay clay triangle from paper clips. The triangle was
then supported over the scale with a tripod made from paper clips
(google image: clay triangle tripod). The legs of the tripod rest on
the table that the scal sits on. For the spoon, a Speedball Linoleum
Cutter No.1 works perfectly (google image: linoleum cutter). It's a
little piece of metal about 3.5cm long. The cutting end is sharp and v
shaped, the fixture side is dull and u shaped. So he can make a
largeish initial deposit with the U side, and then make another deposit
with a few gentle taps to the V side. He's still practicing with
crushed up OTC pills. A possible problem may be that the long thing
particles of some RCs may clog or get stuck to the funnel.



Edited by: ISBN

[Nagognog2]

I pre-weigh an empty gelatin capsule while wearing disposable latex gloves. Then I transfer the (x) into same using a fine stainless-steel surgical spatula until the desired amount has been reached. However, I do have very steady hands. If your friend doesn't, perhaps you know someone who does?

[allyourbase]

you should look into a spoon instead.I have various tiny metal and glass spoons, some can hold an entire gram of a given material, while others cannot handle more than about 10 milligrams.


if you know the weight per volume of your material, spooning can bevery efficient.


if you dont know such things the next best thing to do is liquid dosing. start with a known amount, then WITH A CALCULATOR divide the known amount by your desired amount of doses and add a drop of distilled alcohol to the material for every dose.


milligram scales are not only expensive but theyre very delicate. they break very easily. a balance might be better.Edited by: allyourbase

[discobloodbath]

anyone know if the JPrecision 10 is a good scale?

[MrJenkins]

I have the Jprecision 10x.001g scale, it works pretty good for
it's price but i wouldnt trust measuring anything below 5-10mg with
it. It fluctuates a lot especially if you arent in a completely
windless stable environment.
Edited by: MrJenkins

[paradies]

I have a Gem-Pro 50 which has been very reliable for me. I've taken very good care of it...I actually put it back into it's cover and then even the cardboard box it fits into. I've also not taken it around...it stays right here. That also means the temperature is always even so it doesn't need long times to warm up or cool down. Also, I always calibrate it each time I use it...just to be sure it is set right. Either I've got a really good Gem-Pro (which could be the case...mass produced anythings will have a wide range of qualities), or the fact I take excellent care of it and don't cart it around helps I'm sure.

[radiometer]

Here's another vote for the Tanita 1210. They can be had new for very
close to $200 if you search.

I recommend getting a set of calibration masses such as this one:

http://www.itinscale.com/calibration_weights.htm#6

Otherwise, there's no way to know that your relatively cheap scale is
accurate.

With this I was able to verify that my scale was indeed accurate, what it's
limitations and quirks are, as well as the best methods for getting
accurate, repeatable measurements. The small extra investment made
for a large amount of peace of mind.

I'd feel uncomfortable buying a used one on Ebay unless I had the
calibration masses to assure me the scale had not been damaged.

I recognize what was said above about the relative quality of different
calibration masses. However, the fact that my scale and calibration
masses are in perfect agreement leads me to believe that both are
working according to spec.Edited by: radiometer

Reputation Comments on this post:

thank you nice calibration weights

[nanobrain]

Tanita 1210 is def. worth the additional money.

the thing is ultra cool to look at / play with too.

[Mezza]

Keep an eye on on Ebay - I picked up my Tanita 1210/20g on Ebay for $120 shipped.





Mezza

[William_Again]

I have a JPrecision GemPro 10, it has a 10gm capacity and it is
accurate up to .001g...or so they claim...No matter how many times I
calibrate it it is always off by at least 5mg up to 20mg (you would
think that after claibrating the scale it would think its own
calibration weight weighed correctly...but alas no...) I paid about 130
for it.



Though one thing that is nice is the website where I ordered it from,
after i recieved it I fucked up the claibration weights (dont ask) and
I emailed the owner and he sent me free ones...the shippin gon both was
extremely quick.



Beware of this scale!

[sg43]

Damn, I just ordered a JPrecision GemPro 10...only payed about $80 for it off of ebay, Hopefully ill have better luck.