anecdotally, I have found that barely touching the scale's platform will get it to register small changes. Also make sure no ceiling fans are on they will make it fluctuate.

The scale that River Supply sells is not recommended. No, you should not have bought that one.

You want the AWS LB-501 from Amazon.

Some scales aren't completely accurate. Others just need some time to settle. The one I have I know fluctuates slightly the first 1-2 seconds and then settles on the number so I always prep juice with earphones on and as away as I can from my scale so that even my breathing won't disturb it (it's a sensitive one).

Try recalibrating it and mixing again, might fix up its issue. If not, try when adding drops and nothing changes to huff some air onto it a bit more intensly to make it jump around and then return. You could just also bounce your finger off of it and wait for it to figure out what's going on. Digital tech can be quite confused at times! Good luck!

This is an issue with many of the scales we use. This "jeweller" style scale uses a strain gauge to differentiate and measure weight, but not all strain gauges are equal. A 100 gram strain gauge has the same travel as a 500 gram strain gauge, but 500g on a 100g scale will overload it.

This is a long winded explanation to say the scale you have is good for mixing 60 to 250ml bottles but not very accurate for 10ml (you need a 100g scale for those small quantities).

Try putting something heavier on it then tare it out. Then start. Sometimes that will work with cheaper scales.

My scale registers every drop. I can blow on my scale and it will register it then go back to the weight it had measured. Like what u/4lan9 said, tap the platform or the bottle to kind of get it moving. Take note of the weight before you tap it. Put a drop in and if it doesn't register give it a little tap. Hopefully when it settles it will be one drop heavier than the weight you noted earlier.

Some scales won't register anything before 0.3g

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You can just add the 0.15g of whatever flavor, on top of another thing you're adding.

- Say you're adding 1.5g of Flavor A, then add Flavor B till it reads 1.65g

I've been using the GDEALER DS1 scale for my mixing and have had no issues with it. It's available on Amazon.

I use cheap scale I got from China for 10 bucks... It's not great but it does the job. Just pick up your bottle, swirl it a bit, then put it back down.

I only use the 'tare' function to zero the scale. When I mix, I have a spreadsheet that I fill in as I go along, and use the total weight at each step. That way if it auto-shuts off, I can just pick up where I left off.

I also use a coin as a reference. I have a quarter that weighs 5.67g. I'll usually tare until I get that to measure right, then measure my ingredient until I get close, then weigh the quarter again to see if there's any drift. It there is, I just compensate for it, rather than constantly trying to tare out until it's perfect. If it drifts much past +/- .02, then I'll tare it again.

If it seems to be bouncing all over no matter what, press the scale up and down a few times, and tare it again to your reference.

If it doesn't register a .02 change then that is pretty normal for a cheap non scientific scale. But for my cheapo home scale 3 or 4 drops will register about .06 to .08. For a scale to accurately measure a .01 then you will need to drop a few hundred dollars at least (some scientific lab scales cost thousands). The scale you describe is probably better suited to mixing 60-120ml at a time, for smaller test batches just try to get the amounts in the ballpark, and then do it more accurately in a bigger mix.

Usually .02 per drop

In my case, for tiny amounts, I remove the bottle, add a drop or two, put it back on the scale and check how much did I just add.

If I may offer my two cents: I only mix small quantities (under 150 mL) at a time and I only add the flavors by volume rather than mass. You can pick up a big pack of 1 mL syringes and blunt tip needles (16G, I think or 14G). I find this much more precise when making small, 20 mL tester batches when I have to add 0.1 or 0.05 mL of flavor. I just use the same syringe for the whole batch, wiping off the needle in between flavors and trying to add similar flavors next to each other in case there is a little contamination. Then you can either throw it out or wash it out with hot water and reuse a few more times. When I am adding the nicotine, I also use a syringe, but I use a fresh one so I don’t contaminate the nicotine bottle. I then use the scale for the VG and PG.