Frustrated Red Sea with titration syringe

[wildwilly1]

thank you very much .time to do some testing tonight

 

[Randy Holmes-Farley Verified Community Expert]

You're welcome.

Happy reefing. :)

 

[PeterG]

I think you may have a misunderstanding of how syringes work.



It actually makes NO DIFFERENCE what the air gap is. You could put on a three foot tip, and the liquid would NEVER even enter the barrel, and yet the movement of the plunger will exactly draw in and dispense the amount of fluid that is measured by the travel of the plunger in the barrel. It is the difference in position of the plunger (often most easily measured by the movement of the end of the plunger) after movement that is the only thing that matters.

Thanks Randy. Been wrestling with this question every time I do my RS Foundation testing. Don't know why I didn't look here sooner.

 

[Reef Puncher]

You know, if I stop and think about it... you are right. The Gap would only make a difference if you where using the entire contents of the syringe. The distance that the plunger moves is the amount of fluid used. Makes total sense now lol

im still confused. if i pull the ml to the 1 ml mark. and the syringe moves down the the .2 line. does that mean i used .8ml or liquid? or did i use .7 because there was .1 of air in there? its so danged confusing.

 

[Js.Aqua.Project]

@Reef Puncher
You used .8. 1-.2 = .8.

You do not need to account for the air gap, only mark/measure the distance traveled by the stopper on the syringe.

 

[BeanAnimal]

I too had trouble with this . what I do is draw reagent into syringe with tip on . then remove tip empty syringe and draw back into syringe 1ml . then put tip back on seems to work good that way I have exactly 1ml in syringe and tip is full at start of test and end of test so only have to read what was actually used from the syringe. hope this helps

You can’t do that, the scale on the syringe is off by the volume of the tip then.

 

[Reef Puncher]

@Reef Puncher
You used .8. 1-.2 = .8.

You do not need to account for the air gap, only mark/measure the distance traveled by the stopper on the syringe.

ah ok i thought so, just wanted to be certain. thanks. basically pretend the air is also titration. you count movement of syringe, not just the liquid only.

 

[Randy Holmes-Farley Verified Community Expert]

im still confused. if i pull the ml to the 1 ml mark. and the syringe moves down the the .2 line. does that mean i used .8ml or liquid? or did i use .7 because there was .1 of air in there? its so danged confusing.

I show exactly how to read a syringe using a picture here;

https://www.reef2reef.com/threads/reef-chemistry-question-of-the-day-161-using-a-syringe.226267/