Just thought this would help people that don't know how to properly use milligramme scales

1) Turn on the unit, and calibrate it using the instructions included with the device. After callibrating, check again that the 10g calibration weight gives a reading 10.000g. If it doesnt, then re-calibrate, making sure there are no drafts or vibrations that are effecting it.



2) Next, place the "scale pan" (for want of a better term) on the weighing platform and make a note of this weight of the pan - it should be in the zone of 1.197g with the HA-20's pan but check what the reading is for your pan. And weigh it twice to double check the figure.



3)Take the pan OFF the weighing platform and then add some of the chemical onto it. This is the key bit of information - do not add material to the scale pan when it is on the weighing platform, it will most likely not register the weight accurately as the chemical is added! Only after that, place the scale pan back on the weighing platform.



4) Make a note of the new reading and then subtract the weight of the scale pan, (e.g. in this example 1.197g) from the total weight shown. So for example, if the scale now shows a reading of 1.215g, then you know you have 18mg of material on the pan.



5) If this is too much and you wanted to weigh out less, say you only want to weigh 13mg, then take the pan off the weighing platform and remove some material. Then place the pan back on the weighing platform and take a note of the new reading. If it now reads 1.210g then you know you have the desired 13mg!



6) But suppose you really wanted 20mg. Ok, take the scale pan off the weighing platform, add a little more chemical and place it back on the platform. If the new reading is now 2.217g then you've likely got your 20mg. If not then take the scale pan off again and repeat until you hit the target.

Interesting. Do you have proof that adding the material to the "pan" when it's on the scales shows wrong amount?

I use (and I guess many others here) this kind of scales:

how about just taring the scale?
this is the proper method after calibrating, and putting a wiegh boat/paper on the tray.
a scale is basically like most other instruments...a voltmeter. the tare acts as an autozero.

to test the accuracy, obtain a micropipette (and some tips), and pipette various amounts of deionized or distilled water onto a weighboat on the tared balance; 20 ul should weigh out to 20 mg. (H20 d = 1 g/1 ml)

I find my readings come out exactly the same whether I take the pan off and add material or add it while the pan is on the scale.

One tip I can give (don't remember where I read this). Scales weigh more accurately towards the middle of their range. The scale pictured is the one I use and it weighs up to 20 grams. A US quarter weighs somewhere around 8 grams. So I put the quarter in the weighing pan, then put a small square cutout from a playing card on top. Tare the scale, then add material.

The playing card makes it easier to move the material after weighing without it all sticking to the pan. And it folds in half so I can slide it down inside my GVG so it doesn't spill at all.

This

1. Put the weighing platform on the scale
2. Tare the scale
3. Weigh your goods

voila

I had just copy and pasted this information from a website. Apparently it's more accurate weighing this way but if no one notices any difference then this post doesn't really matter

I don't think weighing dmt in this manner will make much difference but it may help if using ultra potent RC'S for example.

I must say I have good experience with the method mentioned by DeMenTed.. Even if you tare the scale, I find that as you get in the lower limits of precision, it is better to take it off and add back to the scale after the substance is added. It's as if the scale needs a bit more to "round up" the milligram if it's added in too small increments.

I just do repeatability trials with the aforementioned method using deionized water at 25 C
(this is standard procedure for calibrating micropipettes too).
the typical limit of accurate measurement is around 5 mg on these cheapy mg scales, although I was able to reproducibly measure out 3 mg (triplicate) on an AMW DIA-10.

I would love to see a picture of benzy's chem set

I would also suggest powering the scale for 10 minutes to let the electronics and the strain gauge stabilize in temperature. Temperature drifts caused by the scale electronics warming up will cause weight measurement to drift especially when first turned on. Although the displays of scales are digital, the front end electronics is analog and it does drift. Also be sure that the batteries are fresh, or if you can power it from AC then plug it in.

The scale must also be kept out of drafts and away from strong electromagnetic fields which can be generated by COMPUTERS, high powered lighting ballasts (especially electronic ballasts), transmitters, etc. Cell phones are transmitters by the way...

Another thing to note is that when you're calibrating your scale it's important to handle your calibration weights using pliers. That prevents any skin grease from sticking to your weight and increasing it's weight slightly, miscalibrating your scale. If you did handle your calibration weights by bare skin I advise to clean them with pure alcohol gently.

Thankyou DeMenTed! Thankyou endless, Benzyme, Snoz, Tele and all the fellow nexians for
this valuable post!

I've often wondered if I just couldn't afford decent equipment or if others had similar

problems with accuracy...I've even taken to weighting a heavier amount (say for eg.: 1

gram) and volumetricly (is that a word?! not sure...lol!) dividing it, visually, into ten

even (looking) piles of approximatly 100mg. Then dividing one of those piles of 100mg.

into ten even (looking) piles of 10mg. and weighting several of those piles to get a good

idea of what 10mg. of a substance looks like since I've used scales that where inaccurate

or insensitive to almost 20mg.

VoidTraveler and Rivea; I never thought of that and wouldn't have without someone to teach

me!

You people are my favorite people that I've never even met and don't even know!

This Nexus rocks! Again; thanks.

Thank you all for these tips i will test these.

As i have $180 scales and i notice sometimes yes that they do not move (sometimes) when i put on little crystals. plrrrrr