hi, am writing to ask about the mpx2100ap sensor , since it is an absolute pressure with 0kp to 100kp , i want to know what is its output at rest when no pressure is applied because the atmospheric pressure is 100kp so will it be at its maximum rating or the atmospheric pressure is negligible . actually i need this since am using in shcool project. thanksss
By no pressure, do you mean 0kPa or atmospheric pressure
Reading the first few paragraphs in the MPX2100 datasheet would have answered your question right away.
The absolute sensor has a built-in reference vacuum. The
output voltage will decrease as vacuum, relative to ambient,
is drawn on the pressure (P1) side.
The 'A' in MPX2100AP stands for absolute.
You seem to have a vacuum sensor.
Leo..
I mean when i don't apply any pressure, so the atmospheric pressure is the only pressure that exists .
In my project i want to measure the pressure of a liquid that is supposed to be in a small tank of 2 litres, so if at rest the sensor is sensing 100kpa which is the maximum value for the sensor, how it will work if an added pressure is applied!!, is it useless for me ??
Then as you suspect, it will read 100kPa
The output will be full scale (40mV) and fall as you apply vacuum (suck) on the port.
Yeah But it still confusing me , how can i use this sensor if it's already sensing its maximum value
Yes.
Did you not read post #3? Allow me to repeat the salient part.
The absolute sensor has a built-in reference vacuum. The
output voltage will decrease as vacuum, relative to ambient,
is drawn on the pressure (P1) side.
You have a 0-100kPa sensor. With a built in vacuum reference. Reduce pressure on the sensor's port, and the output decreases. That's it. It can't measure higher than 100kPa absolute. What part of this is unclear?
Why not simply say what you are trying to do? Then someone can suggest how to do it.
Sir , the unclear part is that the atmospheric pressure is always exists , so this sensor is useless or it has some applications the pressure is under 100kpa
It measures pressure RELATIVE TO THE BUILT-IN VACUUM REFERENCE, not relative to ambient. How many different ways does this have to be said before you get it?
It's a vacuum sensor.
In my project i want to measure the pressure of a liquid that is supposed to be in a small tank of 2 litres, so if at rest the sensor is sensing 100kpa which is the maximum value for the sensor, how it will work if an added pressure is applied!!, is it useless for me ??
What maximum pressure do you expect?
It's a VACUUM sensor. As others have already said. It's already maxed out at atmospheric pressure. What you WANT it to do is irrelevant. You've chosen the wrong sensor for your application. You need a differential sensor with one port exposed to atmospheric and the other port capable of being submerged in whatever liquid you're using.
Can you post a simple drawing or photo of your apparatus?
Thanks for your clarification, actually my teacher propose this sensor to me , so am trying to figure out how it works since i have no idea about this sensor