accuracy of syringes

[Heabob]

Correct me if I am wrong but if you are using a syringe with a needle and pull up the liquid until it is at the exact measurement you want (say 1ml), there will be slightly more liquid drawn up total because of the space in the tip. However, when you depress the plunger fully you would still be left with the liquid in the tip, therefore making the measurement exact (or as near as humanly possible). Am I wrong on this?

I am truly interested since my husband had asked me the same thing about the measurements not being exact with the syringes and this is basically what I told him.

True, syringes are not perfect, and drops are not perfect, but measuring by weight should be perfect.

But I guess I'm not perfect, so I just use drops and syringes, good enough for me, lol.

It's about whatever "you" like best, in the end, anyway, right...

 

[Exchaner]

I use a thin straw for anything over .5ml.... I dip one in liquid and mark the level for 1ml, 1.5ml 2ml. It doesn't work for tiny measurements but otherwise it is accurate for round amounts.

 

[zoiDman]

True, syringes are not perfect, and drops are not perfect, but measuring by weight should be perfect.

But I guess I'm not perfect, so I just use drops and syringes, good enough for me, lol.

It's about whatever "you" like best, in the end, anyway, right...

I think this is what People who do DIY need to Ask themselves. How Good does it Need to be?

Because sooner or Later you can Reach a Point where you Can't Taste the Difference of Smaller and Smaller Measurements. And at that Point, a Person should Stop Striving for Higher Perfection. Because it Isn't Needed Anymore.

 

[Spazmelda]

One other thing to consider when striving (over-striving, IMO) for accuracy and/or precision, is the consistency of your starting materials. Do you need to be able to measure your nicotine to 2-3 decimal places when the nicotine content in your base can be +/- 1-2%? Does it matter much if you are vaping 11.5 mg/ml nicotine or 12.76 mg/ml nicotine? How precise and accurate does your measurement need to be when measuring propylene glycol or vegetable glycerin that comes 99.5% pure but probably absorbs some amount of water every time you open the bottle? What about flavors, how consistent are batches of flavors from one to the next? Do the flavors degrade as they sit around and if so, by how much? How much water has your flavor absorbed, since it's carried usually in propylene glycol?

It's my opinion that, depending on the amount you are making, fractions of a ml here and there don't make much difference. You don't want to be vaping nicotine that's too high, definitely. And you want your recipes to be fairly reproducible, but this isn't rocket science or molecular biology. You simply don't have to (and can't be) perfect.

 

[zoiDman]

Correct me if I am wrong but if you are using a syringe with a needle and pull up the liquid until it is at the exact measurement you want (say 1ml), there will be slightly more liquid drawn up total because of the space in the tip. However, when you depress the plunger fully you would still be left with the liquid in the tip, therefore making the measurement exact (or as near as humanly possible). Am I wrong on this?

I am truly interested since my husband had asked me the same thing about the measurements not being exact with the syringes and this is basically what I told him.

No... You are Correct.

As long as you Draw up to a Line, and then just Depress once, you are Precise and as Accurate as the Line is.

Where people get Measurement Problems is when they Attempt to get the Liquid that Remains in the Needle Out. Because the Volume of the Needle will Vary with it's ID and its Length.

 

[Boletus]

I do mostly VG mixes, so I like to have a bit of water in it. I use the same syringe for everything (not ideal, but it's what I have right now), so I draw water into the syringe until I can see it in the barrel, and then I push the plunger all the way back in, expelling most of the water into the sink. Now the "dead space" in the needle and tip of the syringe is filled with water. Then I do all of my measurements except the water, putting the VG in last. Then I draw my desired amount of water into the syringe, shake it a bit to mix the residual VG with the water, and put that in the mix. When I am done, I have the about same amount of water in the syringe tip as when I started (plus a trace of VG, which I ignore), which gets squirted into the sink as I rinse the syringe.

Just another way of doing it that may not be better than any other, but it works for me. It's not extremely precise, but it is repeatable. I will get a scale eventually though.

 

[cbabbman]

.......
I measure out the amount of PG I need in a recipe, and then I set a bit of it to the side. I use this PG to prime the needle and syringe; I draw up some PG, flip the syringe upside down, expel all of the air and just a drop or two of the PG, then flip it back over and flush the rest of the pg back into the amount I've set aside.

Since the needle is now full of PG, drawing flavors up from 0 to whatever measurement I need means I get that amount of flavoring, plus a needle full of PG. I expel that flavor into the mix, wipe the outside of the needle with a PG soaked paper towel, and then move on to the next flavor. Since the needle is still full of fluid, there's no need to start the process over again unless I accidentally draw some air into the syringe. (ETA: If I'm using some really strong or contrasting flavors, I'll flush the syringe with a round of PG, or even change syringes. That's pretty rare though; I usually only do this with potent tobacco flavors, or when I'm using espresso, etc.)

At the end of the recipe, I draw the remaining PG I've set aside, and then put it into the mix. Finally, I draw a syringe full of air, allow the little remaining liquid to pool at the needle end of the syringe, and then blow it out into the mix.

...............
.

good lord... that's far too much work and potential for error/cross contamination of flavors IMHO...

I use a 300g/0.001g scale from tmart that I got for $95. I have a 200g calibration weight. I calibrate about once a week and the scale never drifts more than .002g or so. I have about 30 droppers and 2 squeeze bottles for PG & VG.

My mixing routine is:

Put bottle to mix in on the scale, tare
Add PG, tare
Add VG tare
Add Nic, tare
Squeeze in flavorings or use a dropper for flavors that don't have a dropper built in, tare

Clean droppers

Done.

fantastically easy, repeatable and quick... and at minimum, as accurate as anyone trying to calibrate drops or eyeballing syringes

I just don't see how it could possibly be any easier... Of course, each to their own and whatever fits their style, but I would have given up DIY months ago if I had to go through procedures like this every time I mixed something up...

No disrespect intended

 

[Spazzer]

good lord... that's far too much work and potential for error/cross contamination of flavors IMHO...

I use a 300g/0.001g scale from tmart that I got for $95. I have a 200g calibration weight. I calibrate about once a week and the scale never drifts more than .002g or so. I have about 30 droppers and 2 squeeze bottles for PG & VG.

My mixing routine is:

Put bottle to mix in on the scale, tare
Add PG, tare
Add VG tare
Add Nic, tare
Squeeze in flavorings or use a dropper for flavors that don't have a dropper built in, tare

Clean droppers

Done.

fantastically easy, repeatable and quick... and at minimum, as accurate as anyone trying to calibrate drops or eyeballing syringes

I just don't see how it could possibly be any easier... Of course, each to their own and whatever fits their style, but I would have given up DIY months ago if I had to go through procedures like this every time I mixed something up...

No disrespect intended

I too use a scale for mixing and my procedure is the same except I add the nic first just in case I make a mistake. Then it can be corrected before the PG and VG are added.

Couldn't be easier or quicker!

 

[Steelgirl]

I have a question along these lines too. Hope it doesn't come off as sounding dorky. Inside the syringe is that thick rubber stopper thing. Do you take the measurement from the bottom of the rubber (kind of pointy bottom) or do you use the top of the rubber thing to spot the number printed on the syringe. It's a difference of about one ml isn't it? I've been using the bottom edge to mark the spot number printed on the syringe.

Thanks.

 

[zoiDman]

I have a question along these lines too. Hope it doesn't come off as sounding dorky. Inside the syringe is that thick rubber stopper thing. Do you take the measurement from the bottom of the rubber (kind of pointy bottom) or do you use the top of the rubber thing to spot the number printed on the syringe. It's a difference of about one ml isn't it? I've been using the bottom edge to mark the spot number printed on the syringe.

Thanks.

You should be Gauging where the Plunger makes Contact with the Liquid.

 

[Steelgirl]

You should be Gauging where the Plunger makes Contact with the Liquid.

Perfect. Thank you very much for quick answer and for making it so clear.

 

[jpasint]

Correct me if I am wrong but if you are using a syringe with a needle and pull up the liquid until it is at the exact measurement you want (say 1ml), there will be slightly more liquid drawn up total because of the space in the tip. However, when you depress the plunger fully you would still be left with the liquid in the tip, therefore making the measurement exact (or as near as humanly possible). Am I wrong on this?

I am truly interested since my husband had asked me the same thing about the measurements not being exact with the syringes and this is basically what I told him.

Exactly. I have tested this over and over with very expensive and accurate glass syringes so I know it for a sure.

 

[cjcaddy]

pretty much what zoiDman said is correct-found this link on another thread:
Murphy's Machines - How To Use A Syringe

 

[kas122461]

I just wanted to say, that I did my measuring this way last weekend, and it worked great. With all my mixes before this, when I was done I always had more than I was supposed to, this time it was right on the money. I thought I was doing something wrong, I could not figure out why, I kept getting to much in the end, when I was being so careful.

Thanks for the tip Mr. Zoidmad

KAS

Sounds like you didn't do a "Between the Lines" measurement.

To Dispense 1ml, try drawing 1.5ml into the Syringe and then Purge any Air in the Barrel until you have 1.2ml in the Barrel. (The 1.2ml Doesn't matter and it can be Anything Greater than 1ml). Now Dispense the Flavoring until you get to .2ml on the Barrel and Stop.

1.2ml - .2ml = 1ml

A Syringe may be Calibrated for a Given Needle Length and Gauge. But if a Person uses a Bigger Gauge and or Length, they are going to get More than 1ml if the go from 1ml on the Barrel to Full Depression of the Plunger. And Vica Versa if the Needle is a Smaller Gauge or Length.

---

BTW - I Love your Avatar!

 

[zoiDman]

...

Thanks for the tip Mr. Zoidmad

KAS

Hey No Problem.

Glad to here that things went Smoothly.

BTW - I'm really not a Mad. Slightly Crazy... Sure. 17 Degrees Off Center? Probably. But Definitely Not Mad.

LOL

 

[holimakaru]

I about 1/4 bubble off plumb too ,
Got a scale couple of days ago and checked my syringes and was surprised how accurate they really were.
Had to get the scale cause some flavors melted the syringe before I could get the flavor out.

 

[zoiDman]

I about 1/4 bubble off plumb too View attachment 369440 ,
Got a scale couple of days ago and checked my syringes and was surprised how accurate they really were.
Had to get the scale cause some flavors melted the syringe before I could get the flavor out.

Just curious.

Which Flavorings do you have that can Melt your Syringes?

And do the Flavorings Melt the Body of the Syringe? Or perhaps the Plunger?

 

[Steamix]

If you mix liquids by the bucket , am ml up or down won't matter much.
Small quantities aren't so forgiving on mistakes...

Cobbling together bottle by 10 ml bottle, a precision scale works better, as I'm mixing for others too, some of them have a sensitivity to PG and the band between throat hit and adverse reaction is fairly narrow. Flavours, bases, everthing gets measured out as precisely as possible and weighed to account for the variations of densities. Once I have decent number on the density, all is done by weight. Plunk the empty bottle on the scale, enter the tare weight into a l'il homegrown spreadsheet, and it tells me next reading on the scale for the next ingredient.
Repeatable. Precise.
Biggest hassle is keepin track of all the recipes. :/

 

[holimakaru]

Just curious.

Which Flavorings do you have that can Melt your Syringes?

And do the Flavorings Melt the Body of the Syringe? Or perhaps the Plunger?

Inawera Wera Garden Orange. Sucked up about .2 ml and the plunger stuck in the syringe.
What a mess I made! I have a 1ml glass syringe but my lousy eyes cannot see the graduations

 

[holimakaru]

I Think it melted the body cause the plunger only gets stuck where the flavoring was.