# Help with syringe pressure and Students T test

1. May 7, 2007

I am a doctor with limited mathematics knowledge. I am trying to prove to my medical fraternity that for a given force of aspiration, a smaller syringe generates a higher "negative pressure". I did a small experiment. I hung an one kilogram weight on a 5 ml and 10 ml syringe and connected it to a Digitron electronic manometer. I got the following neg pressure readings (cm Hg).
The 5 ml syringe: 57.3;55.8;56.7;56.6;55.9;56.6;57.4;56.1;56.1;56.6 The 10 ml syringe gave the following: 32.8;32.3;30.7;31.9;31.9;32.6;30.6;33.3;32.1;30.5
I would like to"scientifically" say that the smaller syringe creates a bigger negative pressure.
Would a "Students t" test be an appropriate one to use ? Can I use MS excel do do the test ?

With regards to the posting by light_bulb: for each reading , i gave a 30 second time period for the readings to settle. Hopefully that will look after the time aspect of things ?

Last edited: May 7, 2007
2. May 7, 2007

### light_bulb

you'll be using more force in the same amount of time to compensate for filling more volume, so unless your juggling the amount of force or time the larger syringe will create a higher negative pressure.

i'd just put it down like ml / seconds * 0.19336779 = psi a second at 0 degrees c

Last edited: May 7, 2007