Syringe Lines Not Accurate

I did an experiment today on the amount of drops in various measurement lines on a BD 3ml syringe with a 23g 1.5" needle . I did each test 3 times - 1.5ml averaged 182 drops . 1ml averaged 134 drops ; .5ml averaged 61 drops ; .3ml averaged 34 drops ; .2ml averaged 22 drops - based on this if the 1ml line yields 134 drops - then .5 line should be 67 drops -and .25ml should be 33.5 drops .

so the conclusion to my experiment is the number 3 small line is actually .25ml of liquid . Btw I used water for experiment . Another interesting finding was after the plugger reached the bottom , if I pushed hard on it , 3 more drops came out . Another interesting finding was my Watson brand 10ml bottle seemed to be only about 8.5 - 9ml - but this was just doing a rough calculation doing 2 shots per week . Maybe the amount left in the syringe tip accounts for the lower number yielded .

Since this effects all of us ( who inject ) I could use another persons opinion or someone else to do a test of what amount we are actually getting into our body . I know it is minute and kind of anal , but when injecting several times a week it adds up . I though of using a smaller barrel with a 23g 1.5 needle but don’t know if they are exchangeable . However after I adjust the 3cc barrel lines they can be used effectively and accurately .

The lines will be linear and the diameter is constant. So I can’t see that things would be off by much. Accuracy will be better with insulin syringes and that eliminates the waste space issue. Also around ~$13.00 per 100 at Walmart with their Relion house brand.

Yes it SHOULD be same - the point was it was not according to my test . What would be perfect is if someone else could try this test by counting drops and report their findings

Nobody else concerned that perceived dose my not be actual dose ?

Anyone do experiment yet to count drops

Drops depend in needle gauge and the liquids surface tension. So problem is not well defined. For a given syringe and liquid, any perceived non-linearity suggests an error in the method.

Just count the drops and you will see -

delta V = delta d * area

Another method would be to weigh the amount coming out of syringe - but this would take having a very accurate scale

Tod:Why do you require such accuracy? I would recommend the Pen used to inject Hgh,that Pen measures to the internation Unit. I.E. I use 3-i.u’s of that’s say 21-calibration’s/click’s of the pen. I imagine you require exact,as you are injecting Liquid tomoxifine,or some other hormone,peptide or viamin see ya john

The point is that if you go off the lines on the 3ml syringe - the liquid in the lower amounts ( ie. .30 , .50 ml ) is not consistent with the amount of liquid in the larger amount lines ( 1ml , 1.5ml ) -but the good thing is now that I know that I can adjust for it - in other word when I was injecting 1/4 cc ( 50mg) I used the second line plus 1/2 line - in actuality 1/4cc is 3rd line - if you count the drops ( based on 1cc being most likely to be the accurate part of syringe .

Dont bash me for being OCD - this is just a fun experiment . I tried original experiment again - apparently all drops are not same size - as to know the needle tip is tapper cut . If you hold syringe horizontal so tapper opening is up than drop is smaller than if you hold it with opening down . This variable as not taken into consideration - I will do experiment over with needle and syringe held vertical . I could also measure by transferring liquid from 3ml syringe to a micro syringe barrel to see how much fills up .