MPX2202GP Pressure vs Vacuum

[PhilipSTT]

Hello!

I have a question regarding Sensor MPX2202GP:

Is it possible to use this sensor for positive and negative pressure (vacuum)?
Or will it damage the sensor if vacuum is applied?

We have an application which pumps and sucks and we need to know the pumping
pressure, but after the pumping is completed we pump in the other direction but the
sensor will still be connected.

Do we need a valve to make sure only positive pressure is applied to the sensor?

We do not necessarily need the negative pressure to be measured, but it would be a
nice feature.

Thank you!

Best regards
Philip

[PhilipSTT]

Hi Tomas,

another question, does NXP also do analyzing defective sensors?
(or in our opinion defective sensors)
So is it possible to send you some sensors to check?

We are using this MPX2202GP sensors now already 4 years in our products and we have sometimes defective sensors.
We actually don't know what is the cause or what happened to them.

Direct water/fluid contact as not given at any time, but I am not sure about moisture.

Thank you
BR
Philip

[TomasVaverka]

Hello Philip,

Yes, such an analyze is usually possible.

Our standard procedure for this is to submit a CQI (Customer Quality Incident) request through a distributor you bought the parts from. 

Best regards,

Tomas

[PhilipSTT]

Hi Tomas,

ok thank you very much, we will try that!

Best regards
Phiilp

[PhilipSTT]

Hi Tomas,

thank you for the prompt answer, helped a lot!
Ok so I can confirm this part in our usecase, as we only measure positive pressure, but negative pressure is
applied during use of our product.

Other thing is: How about water pressure, I can see that the MPX2202GP is not confirmed for use with fluids,
is there any way to adopt it? Or do you have sensors for use with fluids?

Thank you!
BR
Philip

[TomasVaverka]

Hello Philip,

We can only warranty that the MPX2202GP will work as long as the internal die of the sensor is not in direct contact with the water.

Other media than dry clean air has the potential to dissolve, or be absorbed by the gel and corrupt the die surface or lead to wire-bond breakage. Some types of media will take longer to corrupt the die than others, so a disposable application is possible.

I would like refer you to the application note AN3728: “Media Compatibility for IPS PRT Pressure Sensors” that would be worth to be considered in addition to the provided information.
AN3728: Media Compatibility for IPS PRT Pressure Sensors
http://www.nxp.com/files/sensors/doc/app_note/AN3728.pdf

We normally recommend that if customers want to use the pressure sensor with a different media than “Dry Clean Air”, they must validate the product performance in their application and assume all risk and liability. A determination must be made if this impact is acceptable for the application.

Possible solutions to use our sensors in applications with other media than dry air:

NXP uses two different types of gels in order to isolate the die from the environment:

The Fluorosilicone Gel (Type FE-53) is being used for all our standard type of pressure sensors, including the MPX2202GP.

Media Resistant Gel (Sifel) is being used for our pressure sensors that are used e.g. in high temperature environments, mainly in automotive applications. All pressure sensors with the designator Z (MPXAZ, MPXVZ, MPXHZ) are those using Media Resistant gel.

Best regards,

Tomas

[PhilipSTT]

Hi Tomas,

thank you for explanation!
So we will test for our application if the sensor is good or not.
Problem with normal SMD Type is that the fixation is not very reliable,
so we had chosen MPX2202GP as it has THT Pins.

We will have a look on your suggested types, thank you very much!

Best regards
Philip

[TomasVaverka · Accepted solution]

Hello Philip,

Our pressure sensors are intended to measure pressure in one direction only (except the MPXV70xx family). Our datasheet characteristics and specifications are reflecting this official way of operation only.

Being said that, when using the MPX2202GP, it is possible to apply a negative pressure up to 200 kPa and you will get a negative differential voltage on the output. The sensor will not be damaged.

Best regards,

Tomas