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Differential pressure sensor

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hemnath

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I have mpxv7002dp differential pressure sensor. And processed and displayed the values on the LCD. I have no problem with it. But the thing is, regarding the maintainence of the sensor. The dust particles is entering into the sensor and blocks the passage for air. How can I avoid this problem and use the sensor for many years without problem . Is there any filter, so that I can avoid the dust particles to enter into the sensor and clean just the filter itself.
 

c_mitra

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If you use any filter it may cause the pressure readings to be unreliable because the filter will offer a variable pressure (drop). I guess an electrostatic precipitator will be more suitable because it will not offer any significant resistance to air flow.
 

KlausST

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Hi,

I don't agree.
A pressure drop will be generated only if there is a (continous) air flow through the filter.
No air flow, no pressure drop.

It's like a resistor in an electrical circuit: No current, no voltage drop.

Klaus
 

c_mitra

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It's like a resistor in an electrical circuit: No current, no voltage drop.

You are right. If one wants to measure a pressure that is varying slowly in time, then the filter does not matter. If you want to measure a pressure that varies rapidly and you want an accurate time stamp then you should worry about the pressure drop across the filter.

Oftentimes you will see that many professional microphones are covered with a foam or even a thin cloth that can block some low frequencies. They act more or less like a high pass filter that block some of the low frequencies.

For non-critical applications, a foam filter (even a HEPA) can be used. If one is using in conjunction with a microprocessor, the calibration and phase shifts can be easily carried out.
 

KlausST

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Hi,

Oftentimes you will see that many professional microphones are covered with a foam or even a thin cloth that can block some low frequencies. They act more or less like a high pass filter that block some of the low frequencies.
I don't think this is compareable to the static air flow problem.

If this acts like a high pass filter ... then it should block low frequencies, do you agree?

But in my eyes, they don't. I may be wrong, but I think the foam mainly reduces noise caused by wind (wind as air flow, not necessary beeing a contiously changing air pressure, like sound). Not the low frequencies, but the audible noise caused by the turbulences around the microphone. Simple low frequencies could be filtered out with electric filters, but the turbulence's noise can't be filtered, it needs to be avoided.
True low frequencies, like the subsonic ones when the door of the studio is opened, can'tbe suppressed by the foam)

But I agree that a filter may have influence on frequency response (moving mass). Thus it would be a good idea for the OP to tell us the frequency range of interest.

Klaus
 

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A lot of speculation considering that the actual application hasn't even been indicated.

The said sensor has to be connected through tubes, it's more likely that they will be blocked by dust particles before any reach the sensor. Even more likely the primary pressure measurement port where the tubes connects.

If actually needed, any of the filter options mentioned above can work for one or another application, depending on the yet undisclosed requirements.
 

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