I am looking for sensor that is the simplest, cheapest or most reliable to detect air flow inside closed pipe.
So there are 2 pcs air pumps / blowers / aerators (220v 1100 watt each) for fish ponds.
These air blowers are connected with 2" PVC plastic pipes.
I will use:
- 2 channel relay 5 volt
- and also contactor.
Day 1, 3, 5, 7 = Pump A will operate.
Day 2, 4, 6 = Pump B will operate.
So at one time, only 1 pump will operate.
Then there are 2 sensors installed near the output/mouth of air blowers to detect the air flow.
I don’t need to measure the speed/pressure of these air blowers.
I just need to know that air blowers are blowing air (or have air going thru the pipes).
They will have 1-way valve so that we are sure which one of the blowers is malfunctioning.
If sensor A cannot detect any air from air blower A, the Photon/Electron will turn on blower B and also do some notification/email. And same applies for sensor B.
Google told me to use:
flex sensor and water flow sensor.
— expensive and continuous hard blowing air will damage/bend it permanently
BMP280 barometric pressure sensor
— I assume air blowing = increase pressure
— not sure how to install it inside the PVC pipes so that it won’t obstruct the airway
— looks suitable but is there any other sensor that I should know?