I bought this sensor because I thought it could be used for measuring both static and differential pressure. I see that it automatically finds differential pressure, well at least I think it does, I ran the example code in the AMS5812 library and the values were very close to 0 (no tubes are hooked up to the sensor). Is it possible to use it to measure the static pressure in an air chamber? and if so how would I do that? Thanks
Could you explain your setup and exactly what measurements you want to perform?
When I use the “-D-B” (Bidirectional, Differential) Sensors;
Port 1 is left open to the atmosphere- to account for changing Barometric Pressure over time
Port 2 is used to perform the pressure measurements.
The setup above would allow you to measure the pressure differential between the air chamber and the current ambient air conditions. This removes the barometric conditions from your measurements.
It all depends on what you want to reference your measurements to. You can always “plug” port 1 but you will be taking measurements biased from the local barometric pressure when it was plugged.
If neither is what you want, you may need the Absolute “-A” variant of the AMS sensor.
The air chamber has air blowing through it. There is a nozzle in the center of the air chamber and I want to measure the differential pressure across the nozzle. Can I hook up the tubing from the front of the nozzle to port 1 on the sensor and the tubing on the other side of the nozzle to port 2 on the sensor?
Let me add more details. I have the AMS5915 0010-D-B sensor that I was planning on using to measure differential pressure across the nozzle in the chamber. Then I have the AMS 5812 0003-D-B that I wanted to use to measure static pressure at the front of the chamber. So for measuring static pressure it makes sense to leave port 1 open to the atmosphere.
So I guess I just want to check if it is possible to hook up both port 1 and port 2 to tubing from the air chamber?
What you explained in Post #4 seems valid to me.
The 5915 will give you the headloss across the nozzle.
The 5812 will give you the operating pressure inside the test chamber (essentially the same as the bias measurement from port #1 of the 5915).
As you probably already seen in the Datasheets, both sensors are temperature compensated to correct for Air Density Changes.
Just for my curiosity, is your Goal to measure Air Flow Rates through the chamber (air speed), or are the nozzle characteristics what’s being analyzed ?
If the goal is Air Flow Rate, you might consider using the Pitot tube from an Air Speed Indicator ($33 on Amazon) that we use on UAV’s (“Drones”), even if it’s for redundant measurements to validate your preliminary results.
The top tube is “active” (measures air pressure from the pitot tube that is open at the front and has air driven into it by airspeed) and the bottom one is “static” (measures ambient air pressure from tube with intakes on the side).
The goal is to just collect pressure measurements and calculate volumetric flow rate. I’m using the sensors so this data can be collected automatically, I’m programming a microcontroller to read the sensors at certain times. Thanks for the help!