multi-phase flow meassuement

I have a small project which I plan to use an Arduino board. I have selected the Arduino Uno type. The system will be measuring air flow rate, water flow rate and pressure in a closed-loop flexible pipe. Air and water will be mixed to flow in a single pipe, two-phase. I want to record the flow rates before they mix and then to measure the system pressure after the two fluids mix.
I want to know the water, air and pressure sensors compatible with the Arduino Uno
Flexible Pipe size is 1/2 inch, the flow rate range is 0-30l/min, the pressure is 0-1bar.
Can you please suggest for the sensors to use?
Thanks and regards
Jeremiah

Anything with a 4-20mA, voltage or pulse output can easily be connected to an Arduino. This covers the vast majority of industrial type sensors.

How much money are you allowed to spend?
What resolution, accuracy and frequency response do you need?

To further complicate matters, all mechanical flow sensors suffer from poor accuracy at the lower end of their working range. Some may not even register a flow until it is above some minimum level.

doctorjk:
I want to know the water, air and pressure sensors compatible with the Arduino Uno

Most sensors can be read by an Arduino - basically anything that's meant to be read by something else, sensors that come complete with display and so are generally not easy or even impossible to read out with an Arduino.

Tell us which sensors you have set your eyes upon, and we'll be happy to comment on how to read them with an Arduino (or let you know when it's not possible).