Looking to read the internal pressure of a vessel. Essentially have a steel pressure vessel with a removable lid. I'll be placing the entire project inside and taking readings via bluetooth. No openings to run wires or probes. I'd be measuring pressure from the 0-30 psi range with .5 resolution needed. Higher range and accuracy is fine but i'd like to keep costs down overall.
I am wondering on the sensor to use. I (think) that an absolute pressure sensor is what I need. I've tried the following and can't seem to get it to work. Wondering if either my code/wiring is off or its not right for this application.
Which i presume would work if i could get the mpx working. Anyone have any thoughts or sensor suggestions? Cheers!
EDIT: Everything else works fine as need with regard to the vessel and the signal. The issue is the proper sensor (or configuration) for reading pressure. Thanks!
RF communication isn't going to work.
The only way of getting data though steel is using acoustic/vibration or a radioactive source.
Perhaps use a solenoid to vibrate the interior surface at a frequency proportional to the pressure. Use a microphone on the outside to detect the frequency.
If your device is battery powered you should first check to see if the battery is designed to work at elevated pressures, and how it behaves when the pressure is released and gasses dissolved in the electrolyte try to come out of solution. Worst case scenario - the battery expands and vents or just explodes.
shogun007:
So the question is how to read the pressure properly, not on getting the signal out, which already works as needed. Sorry for the confusion.
What gases or liquids are inside your pressure vessel?
The MPX sensor you link to has a max output of 40mv which could benefit from amplification when used with an Arduino otherwise you're operating at the bottom end of the A to D converter range.
It's possible that you are successfully reading a signal, but the data is masked by noise and quantisation errors.
Air or CO2 are both options. I'll look into amplifying the signal, im quite new to this so I appreciate the suggestion. i'm also open to different sensors if that makes things easier. Thanks!
The sensor from digikey only goes to 29 PSI so that won't work for 30 PSI. It's heading in the right direction. Use their parametric part search to find an Absolute sensor that covers the range and has a 5V SPI or I2C interface to make it easy to use with an Arduino.
