Make a differential pressure reading and/or liquid height with an anlog sensor
The MPXV5010DP sensor from NXP is used to measure a differential pression. Basically, it contains a membrane with 2 inputs and a specific sensor measuring the membrane distortion. The distortion allows to determine the difference of pressure between the 2 inputs.
By exemple, one input is left without connection (so it takes the athmospheric pressure) and the second one connected to a silicon tube placed at the bottom of a container. This way, we can measure the liquid pressure and determine the liquid height in the container.
This sensor is designed to be used with hospital bed, cooling system, manufacturing process, whassing machine (water height), pressure measurement or liquid height measurement device.
If you need it, we do propose silicone tube compatible with this sensor.
This is a SMD component which is quitte bigger. It will be easy to solder on some prototyping board.
How it works ?
The basic principle is quite simple, the sensor measure the distortion of a piece placed between the two sections.
The distortion does indicates the difference of pressure and is converted to an analog output.
- Vout = Vs x (0.09 x P + 0.04)
- Vs : supply voltage (5V)
- P : the pressure difference in kPa
So, it is possible to measure the difference of pression P (in kPa) from the output voltage of the sensor (Vout)
- P in kPa = ( ( Vout / Vs ) - 0.04 ) / 0.09
At the end, it is possible to measure the height of water (in mm) from the kPa pressure.
The 1000 coefficient is used to transform the meter unit to millimetres.
- H2O mm = P * 0.1019 * 1000
How to use
To use this senor, you only need to power it up and measure the output voltage.
Not that decoupling capacitors are required for a better precision and stability of the output signal.
Be aware that Pressure P1 > P2.
Next, you only need to wire the sensor output (VOut) to an analog input of the microcontroller.
- Max error: 5.0% in the range of 0°C to 85°C
- Suited to be used with microcontroler
- Durable Epoxy case and thermoplastic
- Temperature compensation from -40°C to +125°C
- SMD component (quite easy to solder on a prototyping board)
- Power supplu: 5V
- Currant: 5mA in typical usage (up to 10mA max)
- Output: analog from 0 to 5V
- Pressure range: 0 to 10 kPa (0 to 1019 mm of water)
- MPXV5010DP datasheet (pdf, NXP/FreeScale)