How can I use a differential sensor (Air pressure)?

Thread Starter

nayarasmontes

Joined Aug 18, 2018
3
Hello!

I need to verify a pump's air pressure continuously. Then, I've acquired the following sensor:

https://simstsensor.en.made-in-chin...ifferential-Pressure-Sensor-Chip-Psg010r.html

https://softroboticstoolkit.com/files/sorotoolkit/files/mps20n0040d-s_datasheet.pdf

Due to it's a differential sensor, it only provides a signal peak (output) when there's a pressure change in the system. After its signal peak, its output goes back to the referential signal (about zero). How can I use this sensor in my application?

Regards,

Nayara Montes.
 

MrChips

Joined Oct 2, 2009
31,076
Welcome to AAC!

That is not what a differential pressure sensor means.

Differential pressure means that the output of the sensor is with reference to some known pressure. That reference pressure will be the current atmospheric pressure at the location where the sensor is situated. For example, if the sensor is at sea level, the output might be 0V. If the sensor is moved to a higher elevation, the output will still be 0V.

The other type of pressure sensor is called absolute pressure sensor. This type gives an output that is proportional to the absolute pressure. In this case, the output will change depending on the elevation of the sensor.
 

OBW0549

Joined Mar 2, 2015
3,566
Differential pressure means that the output of the sensor is with reference to some known pressure. That reference pressure will be the current atmospheric pressure at the location where the sensor is situated.
Strictly speaking, what you've described is known as a gauge pressure sensor. Such sensors have one port, for the unknown pressure, and measure that pressure relative to current atmospheric pressure.

A true differential pressure sensor has two ports, one leading to each side of the pressure sensing diaphragm, and it measures the pressure difference between them independent of the surrounding atmospheric pressure (unless one of the ports is left open to the atmosphere, in which case it functions as a gauge pressure sensor).

An absolute pressure sensor is as you've described; these sensors have a small evacuated chamber on one side of the sensing diaphragm, so the unknown pressure is measured against a vacuum.
 

Thread Starter

nayarasmontes

Joined Aug 18, 2018
3
Welcome to AAC!

That is not what a differential pressure sensor means.

Differential pressure means that the output of the sensor is with reference to some known pressure. That reference pressure will be the current atmospheric pressure at the location where the sensor is situated. For example, if the sensor is at sea level, the output might be 0V. If the sensor is moved to a higher elevation, the output will still be 0V.

The other type of pressure sensor is called absolute pressure sensor. This type gives an output that is proportional to the absolute pressure. In this case, the output will change depending on the elevation of the sensor.
MrChipps, thank you for your reply! Ok, I mixed the concepts; however, do you have any idea of how I can use my sensor for my application?
 

Thread Starter

nayarasmontes

Joined Aug 18, 2018
3
Strictly speaking, what you've described is known as a gauge pressure sensor. Such sensors have one port, for the unknown pressure, and measure that pressure relative to current atmospheric pressure.

A true differential pressure sensor has two ports, one leading to each side of the pressure sensing diaphragm, and it measures the pressure difference between them independent of the surrounding atmospheric pressure (unless one of the ports is left open to the atmosphere, in which case it functions as a gauge pressure sensor).

An absolute pressure sensor is as you've described; these sensors have a small evacuated chamber on one side of the sensing diaphragm, so the unknown pressure is measured against a vacuum.
Thank you for replying, OBW0549! Do you know if there's a way I can use my absolute pressure sensor for my application? I need to close a pneumatic loop and use the current value of pump pressure for it.
 

OBW0549

Joined Mar 2, 2015
3,566
Thank you for replying, OBW0549! Do you know if there's a way I can use my absolute pressure sensor for my application? I need to close a pneumatic loop and use the current value of pump pressure for it.
I should think it will suffice for the job, provided its pressure range is appropriate for the pump pressure.
 
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