While I agree with you in principle the syringes are not made to dispense a volume from one volume mark to the other. You will always either have to less or to much volume. You are suppose to draw the volume needed and then dispense the whole volume drawn. So as I tried to explain in my earlier post draw more volume then need with tip attached. Invert get rid of bubbles pushing up plunger while the syringe is inverted. Than turn the tip down and slowly push in plunger until you hit the wanted volume mark. Dispense wanted volume. Discard tip or wash with dead volume or suck in additional air to push out volume in the tip.It doesn't matter if the green cap is on or off. When you start with the syringe all the way pressed out and then suck it back to the 1mm mark, you will have more then 1mm. But when you then push it out (aka displacement), not all of it will go out. You will have some left in the tip of the syringe. Only 1mm of solution leaves the syringe.
When you fill up the syringe and pull it back to 1mm like the picture above, the red area fills up first and then the blue area. So, you have more then 1mm of solution in the syringe. But when you push out the solution, you are only displacing 1mm of solution (from the 1mm mark to the 0mm mark.) The red area will still have solution in it even though the syringe is pushed all the way.
If it helps to understand the principle, think of pulling the stopper back to the 2mm mark.
If you only want 1mm of solution, you would push the stopper from the 2mm mark to the 1mm mark (blue area). You displace 1mm of solution. The rest of the red area remains full of solution.
I'm afraid you're mistaken. That's why vets and doctors can and do put different sized needles on the same syringe. Even though the needles are different sizes and hold different amounts in them, they can still give an accurate measurement by the displacement of the solution.
you wont get your correct dosage if you go to the top of the plunger, its bottom of plunger where the plastics connect. just before the dome.
No question is a dum question only those with small minds and big egos would see it that way. It’s better to be safe than sorry. Thanks for asking something someone might be too afraid to because they are more worried about what others would think of them. On your way to successful Reefing!
I apologize that as a grown man I can’t read a syringe— but here’s the embarrassing question:
I need 1ml. I assume that in the top photo I have the plunger pulled back correctly— the widest part (first ring) of the plunger is at the 1ml. mark. But what about the fact that this syringe comes with the green attachment? Is it only 1ml. when when the green attachment is OFF? In the top photo, with the green attachment on, am I getting more than 1 ml.? (If so, how do I know where to situate the plunger in order to compensate?)
Help please
but yes as many mentioned with the tip or without the tip if you pull up to the bottom end of the syringe you will get 1 ml. The one rule is though if you are going to use the tip you must have the tip on before taking your sample to ensure accuracy. What are you testing here? Let’s say you pull your sample first and the. You place the tip what’s going to happen is when you are pressing down your filling the tip before your actually dispensing the reagent into the test. I hope this makes sense haha
No question is a dum question only those with small minds and big egos would see it that way. It’s better to be safe than sorry. Thanks for asking something someone might be too afraid to because they are more worried about what others would think of them. On your way to successful Reefing!
