Why do static pressure measurements differ by 300 Pa on opposite sides of a 10 cm pipe?

[can12345]

Homework Statement

Is there any difference if I measure static pressure value from the down side of the pipe or up side of the pipe? I am getting an error just small as 300 pascal when I do zero measurement.
Here I draw the system also. The diameter of pipe is 10 cm. What could be the possible ideas to create 300 pascal differences?

Tranmission lines?
Air bubble?

Homework Equations

The Attempt at a Solution

 

[SteamKing]

Homework Statement

Is there any difference if I measure static pressure value from the down side of the pipe or up side of the pipe? I am getting an error just small as 300 pascal when I do zero measurement.
Here I draw the system also. The diameter of pipe is 10 cm. What could be the possible ideas to create 300 pascal differences?

Tranmission lines?
Air bubble?

Homework Equations

The Attempt at a Solution

It depends on what sort of tolerance your pressure measuring device is capable of obtaining.

A pressure of 300 pascals is nothing. Standard atmospheric pressure is 101,325 pascals.

 

[billy_joule]

Is there any difference if I measure static pressure value from the down side of the pipe or up side of the pipe?

Of course. You've actually measured less than you should expect..Apply pascals law.
I assume this measurement is near the bottom of the range of your device? The data sheet will likely state accuracy is poorer near the upper and lower limits of your devices range.