I wanted to use a sensor to measure pressure in a reactor. I was advised to use the HX711. I can get raw readings. But after that have no clue how to convert the readings to hPa. Could anyone help me with that?
https://forum.arduino.cc/t/differential-pressure-sensor-code-and-calculation-problem/
the final idea is to use two HX711 sensors and measure the difference between the two (in hPa)
Thanks in advance!
Take some raw sensor data readings at various known pressures, and calibrate the sensor by following the approach outlined in this excellent series of tutorials: Why Calibrate? | Calibrating Sensors | Adafruit Learning System
Besides what @jremington said, you'll have to deal with the different dimensions involved. A HX711 is typically used to report a force measurement from a load cell. So, units of force. However, pressure is a measurement of force / unit area.
There is no need to use a HX711, as that pressure sensor module already has a HX710B fitted.
Not needed if one pressure it atmosphere.
The board measures the differential pressure between the sensor housing and the tube.
As @JohnLincoln says, the board already has a HX chip fitted. The HX710, the smaller version of the HX711. Google for a HX710 library.
Leo..
the two sensors will be placed within two stages of a system, I will compare them to a BMP/BME pressure sensor.
The values i get from HX711 is a bit strange to me. I have no clue what the given values are. mmhg? Pa? hPa? N? N/Pa? kPa? etc etc
So I was wondering how I could get the values to represent (air) pressure
The values are in ADC counts. You need to calibrate them to engineering units.
Simply follow the calibration tutorial linked in post #2. It is not at all difficult.
Incidentally, the calibration process automatically converts units of measurements. Raw sensor values have no units.
This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.