AWS Gemini-20 Milligram Scale 20g x 0.001g–Digital Jewelry/Lab Scale for Powder, Gold, Gems – Includes Calibration Weights, Tweezers & Tray–Tare, Cal, 6 Units (Gemini - 20 - Silver)

A great bargain for a cheap scale. It will perform reasonably well if used carefully. Do not expect it to compete in accuracy or durability against laboratory scales, such as those by Mettler or Sartorius selling for $5-10K. This is a nice little scale with a 4 by 4 inch footprint, about 1-1/2 inch tall, including the clear and colorless hinged draft shield. It fits into a neat magnetic-latch box. Batteries are included, two 10g reference weights, and cheap tweezers. The weighing pan is non-magnetic stainless steel. I have two of these scales to save trips to the weighing room. The first one has been in use for 6 months with no problems. The scale is not quite ready to use as delivered. First, the weighing pan has adhesive residue. It is that sticky gum that can only be removed effectively with citrus oil or a citrus oil cleaner, such as Goo Gone. Second, and as others have noted, the pan sits too low on the scale body, and often touches the body of the scale during weighing. This, of course, will not work. The remedy is to glue a 10 mm diameter by about 0.5 mm thick non-magnetic metal washer to the underside of the pan. See my photograph at top of the Amazon listing. Although this will reduce the weighing capacity of the scale by the weight of the washer, it is insignificant. The washer I used weighed about 530 mg. Third, the tweezers are crude. If you have any serious weighing to do, you really should buy some quality tweezers with about tip #2. Dumont (Swiss) and others make good stuff. Of course, a single quality tweezer can easily cost more than this scale. You can economize by buying their epoxy coated electronic tweezers. NOW, REAL TESTING. How accurate? How precise? To test, I used a set of laboratory reference weights, and an older Mettler Toledo AG204 DeltaRange scale in the lab. This is an expensive machine (about $5-10K depending on features) that measures to 0.1 mg. First off, on the Mettler, the two 10 g AWS calibration weights weighed in at 9.9991 g and 10.0001 g. Not bad; they were within a milligram. How about precision? Took a 1000 mg lab reference weight and weighed it on the AWS ten times, with a complete on/off/tare between each weighing and a closed draft hood, in mg: 999, 1003,1001, 1001, 1000, 1000, 998, 998, 1000, 998. Not too bad. Variation of 5 mg. Perhaps with careful placement, a solid surface, and a quiet environment, this variation could be reduced. How about accuracy? Here are side-by-side measurements of reference weights on the Mettler and the AWS. The scales were not tared each time. Just put the weight on the pan. The AWS was not calibrated first trial, calibrated on the second trial. Accuracy could surely be improved with taring, stable environment, etc. Calibration weights, in mg - Mettler - uncalibrated AWS (calibrated AWS) 5 - 5.0 - 5 (5) 10 - 10.0 - 10 (10) 20 - 20.0 - 19 (19) 50 - 50.0 - 48 (50) 100 - 100.0 - 100 (100) 200 - 200.1 - 200 (199) 500 - 499.8 - 501 (499) 1000 - 1000.3 - 1001 (999) 2000 - 2000.0 - 2001 (2000) 5000 - 5000.2 - 5005 (5000) 10000 - 9999.6 - 10011 (9999) 20000 - 20000.0 - 20022 (20002) Again, this is impressive. With calibration, the measurements were off by no more than a milligram or two. My recommendation is that if you need an inexpensive scale to measure within a few milligrams, and are willing to calibrate manually, buy this scale. If you must have absolute accuracy, set aside at least $10-20K on a laboratory scale, stand, and accessories, and dedicated weighing room. And if you need real accuracy, get an equal-arm balance. Update 30 May 2012 These two scales have been in use for over a year. Still perform well. They have been repeatedly tested. The measurements continue to be at least as accurate and precise as given above. Measurements have been published in peer-reviewed scientific journals. Depending on the project needs, and with reference weights and quality scales to verify performance, you can use this scale for scientific research. And remember, when you are weighing to the milligram and below, even the best scale will perform poorly with bad technique. This is not some yard-dog scale at a metal recycling plant. Have a clean, stable environment. Eliminate vibration and movement. Place the scale on a stable bench (if possible, granite is used in labs). You should be sitting, not standing. Arms off the bench. Eliminate air currents. No magnets. Keep magnetic steels away. Do not breathe directly on the scale. Use the draft shield. Gently place the object to be weighed on the pan. Don't drop it onto the pan. Don't use your fingers. Do not place the object directly on the pan. Use weighing paper or a disposable pan. After placing it on the pan and closing the draft shield, wait 10 seconds or so, for the scale to settle, before recording the weight. If you would like a fuller explanation of good weighing technique, Mettler has an excellent pdf user guide, "Weighing the right way," on their website. Update 4 Sept 2012 Some mention should be made of the pan. It is not the usual flat pan, but rather a dish with a spout. It gives the unfortunate impression that one can load a powder or some such in the dish and then pour it out. Not standard practice. For my use the pan is fine, but others should consider a substitute "pan" out of non-magnetic metal or even cardboard with a washer spacer below. The subject powder or object should be placed on weighing paper or weighing cup. Be sure that there is enough room to close the draft hood, because without the draft hood closed, all milligram and sub-milligram scales are unreliable. Update 9 Sept 2012 For those who have not worked in a lab, some mention should be made, after reading reviews on this scale, just what can be expected from any milligram or submilligram scale, whether it costs $25 or several thousand dollars. At this measurement level, subtle influences can greatly affect measurement. You cannot just throw a sample on the pan and hope for the best. Unfortunately, you need to know what follows. First off, these are scales, not balances. Balances compare a known, measured, mass against an unknown mass. They operate correctly anywhere there is gravity, no matter what the variation, even on the moon. In contrast, the AWS scale and even many expensive laboratory scales measure the force that gravity and centrifugal force of the earth's rotation exerts on a mass. Because gravitational force and centrifugal force vary slightly with the position of the scale on the earth, all these scales need to be calibrated after installation. Expensive scales do this automatically. With cheap scales, such as the AWS, you do this with a calibration weight. Unfortunately, the AWS calibration weight is too big, so you cannot close the draft shield when calibrating. Bad design. Use an inverted small beaker or such as a draft shield. Beyond that, there are several other significant sources of error affecting all scales: 1. Drafts. All drafts cause severe variation in recorded weight. Keep away from windows, doors, HVAC outlets, radiators, etc. Use the draft shield. 2. Vibration and movement. This will cause erratic readings and visible drift. Even absent outside movements, expensive scales take several seconds to settle down. 3. Temperature. Expensive scales measure and compensate for temperature, Cheap scales do not. If you have access to a set of milligram reference weights, you can check for this. 4. Humidity. Not too high, not too low. 5. Light. Light causes heat, which changes the measurement. Keep out of sunlight and bright artificial lights. 6. Leveling. Expensive scales have levels. Cheap scales do not. 7. Sample position on pan. Always place sample in the middle of the pan. 8. Electrostatic charge. A common and severe problem with low humidity and non-conductive weighing vessels, such as glass and plastic. Increase the humidity or change the weighting vessel. 9. Temperature gradients. Differences in pan, weighing vessel, and sample temperature causes severe problems because of convection air currents. 10. Magnetism. Obviously, any magnetic attraction between sample and something else will cause problems. Several materials commonly thought of as non-magnetic are somewhat magnetic. 11. Buoyancy. Because of the sample size, the AWS scale should not be affected much by this, unless one is weighing a large, low-density sample, which would be buoyed by air. 12. Oil and dirt. A common problem with beginners. Don't touch the pan or reference weights with fingers; use a tool, such as forceps or tweezers. Use weighing paper or some sort of weighing vessel on top of the pan. Generally, do not place a sample directly on the pan. If you make a mess, Windex is the usual cleaner for scales. So, for those reviews that claim without qualification that the AWS is accurate down to a milligram, it would take a lot of convincing. On the other hand, for those reviews that claim complete unreliability, assuming the item is not defective, it may just be one of the many inherent weighing problems. Still, a remarkable scale for the price.

I ordered this scale to weigh capsules from a compounding pharmacy. My suspicion was that the drug-to-filler ratio was varying widely. Since one ingredient weighs more than the other, if some capsules in the batch weighed a lot more than others did, there was a good chance I was getting an inconsistent mix of filler to drug. When the scale arrived I followed the calibration instructions (easy-peasy!) and then started weighing the capsules. Yup--big difference. So I took the scale in it's sturdy box and some capsules down to the pharmacy. The pharmacist viewed me with an expression of polite and slightly condescending patience, an "all right, I'll watch--then I'll show you that your cheap little toy doesn't weigh correctly" look. I weighed some capsules and he wrote down the numbers, then took the capsules into the back room to weigh them on his very expensive and accurate scale. When he returned, his look had changed to stunned interest. He asked where I got the scale and how much I had paid for it. He said he was going to recommend it to his customers, who had asked him where they could get an affordable and accurate scale. Yeah, the little round weighing platform is small, but it will accommodate a small pill very well. I didn't have any troubles with the little dish as one person claimed they did-I bet they didn't point the dish's pointed spout towards the calibration weight. That makes a difference! This scale is the REAL DEAL, and does the job. Just read all the instructions and follow them step-by-step. TIPS FOR ACCURACY-- 0) Read the 4 star rating for additional good tips. 1) Calibrate often, as this is a delicate instrument. Calibration is pushing a button and adding 2 weights (included). 2) If you are weighing a capsule or powder to use the little dish (included). 3) Be sure to point the spout on the dish directly at the calibration weight which is stored in a little holder on top of the scale. This scale is VERY sensitive, so if the dish always sits the same way, it will weigh the same each time. 4) When weighing capsules, point one end towards the same stored calibration weight also. That way your capsules and dish will always be in the same position, giving you more "sameness" when weighing things. 5) Always put the scale and accessories (extra calibration weight--you need both to calibrate but one stores on the scale and one in the box--and long tweezers) in the box when done with them. This scale probably won't survive banging around or being dropped on the floor, so put the box where it won't get knocked off a shelf.

*********WHY I PURCHASED THIS SCALE*********** I purchased this scale so I could weight out various Nootropics supplements down to double digit MG. Here is a breakdown of what I needed to weigh and how much of each. I filled #00 gelcaps, for the most part, with the following, using the scale to weigh: 12.5MG of Tianeptine Sodium 300MG Adrafinil Powder 400MG Panax Ginseng Leaf Extract (42+% Gensenosides) 600MG Green Tea Extract (50% EGCG, 98% Polyphenols, PE) 1000MG Choline L-Bitartrate 600MG Phenibut HCL These are all part of the current Nootropics stack I'm trying, and in particular, I was unable to weigh out anything under 1g accurately with the scale I had. So, I purchased this scale to accurately weight 1mg - 1000mg accurately. ***********PERFORMANCE AND QUALITY************** This scale comes with 2 x 10g weights, which are both needed to calibrate the scale. My scale arrived perfectly calibrated, so this was unnecessary. However, at some point I will definitely need to calibrate it since all scales require service at some point, so having the price instruments needed to calibrate is very nice. The scale also came with a nice metal tray for weighing small powders, salts, and supplements out. I found it very convenient. Residue has a tendency to stick to it, but that not the tray's fault. The scan performed with STELLAR accuracy. I opened a couple preweighed gelcaps with ~20-200mg and was able to get an accurate reading down to the mg ever time. It was always spot on. Always make sure you scan is on a perfectly LEVEL, FLAT SURFACE. I can't stress this enough. At first my readings were slightly off, even though the scan was on a flat desk that should have been level. Come to find out the floor was off a couple degrees. When relocating to another surface that was flat AND level (on a level floor) I go consistent, perfect readings. *************Conclusion**************** Overall, I'm extremely happy with this scale. I was a bit upset because I selected Saturday delivery, when ordering it on a friday (I needed it ASAP. When the mail came on Saturday and their was no package, I went back to look at the order and the fee for saturday delivery was no where to be found. This is the second time Amazon ignored the fact that saturday delivery was selected (and both times my total had the $8.99 added which I placed the order, and both times the confirmation email had free shipping selected.......) I did, however, receive it the following monday, which is the next business day. The fact that the scale comes with 2 x 10g weights for calibration, a metal tray for weighing powders, as well as some nice tweezers, I think it's well worth the price. I'm very happy and feel I go exactly what I ordered. ####******######******Please vote if this review was helpful!!!!! Thanks and have a wonderful day!!!!*******#########*******########

First off, one of the only reasons I ordered this scale in the first place is because of how cheap it was for a .001 scale. I use a degital lab balance scale at work but I was also starting to need one in my office. I really didn't want to spend the money or take up the space in my office with a balance scale so I figured I'd give it a try. Little money lost if nothing else it was worth a shot. For the first week after I received the Gemini-20, the scale worked like a dream. I kept good care of it. Cleaned it up after each use. Handled it with special care when moving it. Calibrated it before I used it for the first time everyday and sometimes would do it later in the day just in case. These are all important things for such a small somewhat fragile item. Didn't give me a single problem for exactly 7 days. On the 8th day it wouldn't balance out right with the test weights all of a sudden. I tried to calibrate the scale and it would pass through it and the test weights would be off right after the calibration was done. In just one days time, it seemed to start doing the exact thing I had read about in a few of the reviews. For Example: you add a 10mg weight, it shows 10.005, take that weight off, and put a different 10mg weight and all of a sudden it would read 9.995, take that weight off and let it drop to 0 then put the same weight back and it would be 10.003?!!?!?! I had taken very good care of this cheaper priced scale but it almost didn't pay off. I tried moving it into another corner of the office. I tried new batteries. Even got a level out to make sure it was positioned on a completely level surface. I almost just cut my losses until I saw a small container in the kitchen at my house that just happened to be the about same circumfrance of the weighting tray. I tried it out several times and I was able the check the scales accuracy by simply weighting the tray, filling the container up, emptying it out, reverse those steps or repeating. This was more accurate and consistant with mg's than just the tray When I had doubts I would have to take the scale to 0 with whatever I needed to weight on the scale and work from the -negitive, most of the time having to write it all down over and over to double check. Plus a little annoying having a tray and container you have to try to line up and level off.. I wasn't happy with the product. But that all changed when I got on this site to make a complaint about it working in my office as a hero and quickly turned into a ZERO. Here is where I read a review of a person that glued a small piece of metal to the bottom of the tray to keep it from touching the raised edges where the tray is suppost to set perfectly without touching the sides and only the weighting point. I knew this was part of the problem but was just so frustrated with it I didn't even think about such a small modification! It actually was the only problem with the scale. why it changed on day 8 I don't know. SOOO, now I got a .001 scale that still works pretty well. Always within 3mg accurate give or take I believe. Now that I know the tendencies of this scale, I believe I can get it on the mg 98% of the time. Take good care of it, handle it like a new born, proper storage and just a slight modification and this isn't a bad deal at all. It didn't take me 3 minutes to find and super glue that metal piece on.

I purchase a $19 scale I can't remember which one there's so many of them at that price range and then this one came a couple hours later. The first one that was $19, calibrated fine but it wasn't stable it wasn't linear couldn't measure anything less than 1 gram w accuracy. And then this AWS Gemini 20 showed up a few hours later and it is solid like a rock I mean I'm amazed had no issues calibrated everything down to the thousands of a gram it is a very good scale of course you pay 15 dollars more than the inexpensive ones but it's definitely worth it especially if you're needing measurements accurate under 1.0 g

Slick looking small milligram scale. This could technically be a pocket scale but is better suited to carrying in its provided box, the lid of which is retained by magnets to allow quick easy opening but keep it closed otherwis. The measuring surface by itself is not very large and is better suited to using the saucer that comes with it or something like SEOH Plastic Hexagonal Weigh Boats Micro Dish 100pk which I have bought myself. The Seoh boats provide a larger container then the provided metal saucer. I compared this to an older Ohaus digital scale I had that only goes to .1 grams and they both seemed to match. The provided calibration weights seem fairly cheap. They are not solid and the bottoms seem to be poorly glued on which retains the fine material inside that apparently allows them to tune the weights before shipping. You can pick up and shake the weight and hear the bits bounce around inside. Actually upon opening my box the piece of scotch tape on the plastic bag holding the scale had a few metal bits stuck to it.I was confused where these came from until I pulled the calibration weight stuck in the box out to see the bottom missing. See my photos The real problem to this is when the scale first arrives you will probably need to calibrate it. However to properly calibrate requires BOTH 10 gram weights. So this left me in a bit of pickle where sure I can compare the first 10 gram weight to the 2nd damaged 10 gram weight but since I could not properly calibrate the scale to begin with I am unsure if this comparison is accurate.... I glued the pieces in and it looks like I may be off around +/- .003 grams or so. I considered requesting an exchange or a new set of weights but it seemed like a lot of trouble. I may end up picking up some higher quality calibration weights later but they would likely cost more then the scale itself. Another issue I have is I wish the scale would stay on a little bit longer or have an option to stay permanently on or at least an extra minute or two. You really have to have everything setup and ready to go as soon as the scale is turned on and your weighing container is tared. Conclusion Pro: Cheap, accurate, nice looking scale. Including calibration weights, weighing pan, tweezers Con: Poor calibration weights - one of mine arrived damaged, weighing pan fairly small - recommend purchasing plastic weighing boats

For info: I bought this scale to measure powder for reloading rifle cartridges. So, if you want the scale for something else, a lot of these gripes won't apply to you. There is a lot of fail packed into this cute little device: 1. The little holding pan included with the unit does not properly fit into the recessed weighing platform. More specifically, it touches the sides of the housing if you don't place it perfectly on the weighing surface - just a tiny bit off-center, or tilted, will result in incorrect readings. I tried picking up and replacing the pan with exactly the same amount of powder about 15 times and got significantly different results every time (> 50% deviation). 2. The pan is too flat to hold powder effectively. Trying to get powder from your powder measure into the pan *will* result in a granule covered workbench. Every time. Because of #1 and #2 above I had to find a different container in which to place the powder for weighing. But, trying to find something that would properly fit in the recess, and balance on the weighing surface (which has ridges on the outside), and have sides to properly hold powder, was an 'fun filled' exercise. I finally found plastic glue bottle cap. 3. The accuracy is questionable at higher loads. I compared the accuracy of my initial loads (19-24 grains of powder) to that of my RCBS balance scale and it was perfect. But when charging to loads in the 42-47 grain range this thing was off by .7-1 grains (again, compared to the RCBS balance scale). I trust the RCBS scale. 4. The auto-off feature is designed to make a prostate exam seem like a fun event by comparison. By 'fun' I mean watching puppies being set on fire type of fun. In other words, it is really awful. My workflow is: - Place measure of powder in container, - Weigh powder (and correct weight if needed), - Place powder in cartridge, - Insert and seat bullet, - repeat... Upon conclusion of this workflow I am often *just* in time to see this absurd little troll switch itself off. I had to add 'switch unit on, wait to power up, recalibrate' to my workflow. Yay. 5. There is a gap between the recessed weighing platform and the body of the scale. I strongly suspect that this gap is to reloading powder granules what the Bermuda Triangle is to unsuspecting boats -> a mysterious force that lures them in never to be seen again. Seriously, if you mess any powder near the scale, chances are some of the granules will find their way onto the weighing platform (which, being recessed, is an almost certainty), and any attempts to get the granules out will result in the powder finding its way into the internals of the unit (because of the gap). It's not all doom and gloom though, there is a plus side, the box it comes in is really cool.

This scale is exactly what I needed. If you want the short version of this review then simply put, BUY IT. If you want the longer version then just keep reading. This product came exactly as described and is a very easy product to use and is very accurate from what I understand. The way the product works, is you open it up and turn it on, then press the tare button which will set the scale at 0 calibrating it for whatever is on it. An example would be if you used a small cup style thing to put a product in to weigh it and it not get all over the place. So you tare it off with that product on top and it will show zero and not count the weight of the product holding the powder etc. Then you put it in and weigh it off. The look of this product is beautiful and exactly what I am wanting and looking for. It is very very small and compact and I keep it inside of the little box that it came in for protection. This could be a useful tip if you plan on traveling with it. When I put the 10 gram weight on it just to test and see what the scale would read, it would say around 9.9 so I would assume that It is just saying that it is only.001 off of what it needed to be or something along those lines. I would read into this a little more for a better understanding. But if you are looking for a quick and easy weight that you can use to measure some things out, this is for you. If you are some nit picky scientist that is looking for exact down to the wire no margin for error weighing then you may want to pay for a scientist quality scale. But for the average user weighing out nootropics to put on a pill then that is all you need. Good luck and thank you for reading my review. This is a great product for a new or average user looking for something quick and easy.

Es justo lo que buscaba para pesar gemas pequeñas y conocer cuántos kilates pesan hasta 3 decimales de precisión. Anteriormente compré otras básculas de precios mucho más económicos pero nunca me sirvieron, aprendí mi lección de que es mejor invertir en algo bueno. No se descalibra seguido, pero es recomendable siempre corroborar con una de las pesas de 10 gramos que trae antes de usarla. Trae unas pinzas y un platito para usarlo en modo Tare, en fin, muy recomendable para quienes buscan calidad y excelente precisión.

It met my needs for weighing small amounts of powder, primers, or projectiles as I am a target shooter and find it necessary for reloading ammunition, projectiles, powder etc as well as checking certain ammunition for anomalies. These days one can't rely on some manufacturers when one is chasing perfection.

This scale has been very reliable and easy to use. In terms of accuracy and capability, I would place its skills right between medical grade and standard kitchen grade equipment. It offers great precision without being overly complicated. Definitely a solid choice if you need something more accurate than a food scale.

High precision and easy to use.

**Headline: Precision at Your Fingertips: The AWS American Weigh Scales Portable Milligram Scale** As someone who frequently works with small quantities of materials, having a reliable and precise scale is absolutely crucial. After doing some research, I decided to purchase the AWS American Weigh Scales Portable Milligram Scale with a stainless steel platform from Amazon. Here’s my detailed experience with this product. From the moment I unboxed the AWS Portable Milligram Scale, I was impressed with its sleek design and compact size. The stainless steel platform adds a touch of durability and sophistication, which is reassuring for a tool that's meant to provide high precision. The overall build quality feels solid, and the compact design makes it incredibly portable, fitting easily into my pocket or a small compartment in my bag. One of the standout features of this scale is its accuracy. It can measure down to 0.001 grams (1 milligram), which is perfect for my needs. I use it for measuring small amounts of herbs, spices, and sometimes even tiny components for electronics projects. The precision is outstanding, and it consistently delivers accurate readings, which is something I can't say for other scales I've tried in the past. The backlit LCD display is clear and easy to read, even in low light conditions. This is particularly useful when I’m working late at night or in dimly lit environments. The display shows the weight in several units, including grams, ounces, carats, and grains, making it versatile for different applications. I find myself switching between grams and carats often, and the scale handles these changes seamlessly. Another feature I appreciate is the tare function. This allows me to zero out the weight of any container I’m using, so I only measure the content. It’s a simple feature but incredibly useful, especially when working with powders or liquids that need to be in a container. The operation is straightforward – just place the container on the scale, press the tare button, and the display resets to zero. The scale also comes with a protective cover, which doubles as a weighing tray. This is a thoughtful design choice, as it keeps the scale safe when not in use and provides an additional surface for weighing when needed. I’ve found this especially handy when dealing with loose materials that might spill or scatter easily. In terms of battery life, the scale is powered by two AAA batteries, which are easy to replace and widely available. The scale has an auto-off feature that helps conserve battery life when not in use, which is great because I often forget to turn it off manually. After several weeks of use, I have not encountered any issues with calibration or accuracy. The scale comes with calibration weights, which is a nice inclusion, although I haven’t needed to recalibrate it yet. The initial calibration out of the box was spot on, and it has remained consistent since then. Overall, I am extremely satisfied with the AWS American Weigh Scales Portable Milligram Scale. It offers exceptional precision, a user-friendly interface, and a durable design, all at a reasonable price point. For anyone in need of a reliable and accurate portable scale, whether for professional use or hobbies, I highly recommend this product.