Hi, I have this sensor OEM MPM281 Water Pressure Sensor
link: http://www.alibaba.com/product-detail/7kPa-70MPa-Precision-OEM-MPM281-Water_1986447374.html
Just wonder can this sensor be connected to arduino uno?
It seems to produce a voltage between 2mV and 70mV. You would probably need to amplify that before it could be measured by an Atmega328 - the low range is 0 to 1.1v. However most of the other Atmel chips (such as in the Mega and Leonardo) include an onboard amplifier for analog input.
You can provide an external voltage reference but I don't know what is the lowest acceptable value - if it could be 100mV it should make it possible to read the device directly.
You need to study the relevant Atmel datasheet. This is a bit outside the standard Arduino stuff.
...R
Many of the OEM devices are raw devices. they require the use of some sort of signal conditioning board.
this OEM sensor looks like it could be used with a signal conditioning board to amplify the output.
but you may need to add an industrial op-amp to get an output that is stable enough to be used reliably.
if you are beginner, then I would say to find a device that has the signal conditioning on-board built in.
mechanically, you would need to machine a hole for this to fit into in order to hole it, then add some sort of clamp to make sure it does not move.
you should be able to find a pressure sensor with a threaded connection, and output you can use without modification.
Robin2:
You can provide an external voltage reference but I don't know what is the lowest acceptable value - if it could be 100mV it should make it possible to read the device directly.
On the ATmega328P the minimum is 1.0V.
That's one reason the built in voltage reference is "1.1V". Since it is only +/-10% accurate if they specified it as "1.0V" it might have gone as low as 0.9V which is below the minimum.
Hi, thanks for the quick reply..
My design concept is to assemble pressure sensor, arduino uno and battery. Then put them inside a sphere ball. The ball will roll inside the pipeline and detect leakage based on pressure differential across pipeline. Like what dave-in-nj say, I will need to drill a hole on the surface of sphere ball and place the waterproof pressure sensor outside.
since this sensor is not really suitable for arduino uno. Is there any pressure sensors in the market that fit my concept?
Hi,
Power supply: ≤2.0mADC
Electric connection: diameter0.5mm Kovar pin or 100mm silicon rubber flexible wires
Common mode voltage output: 50% input (typ.)
Input impedance: 3kΩ~8kΩ
Output impedance: 3.5kΩ~6kΩ
Response (10%~90%): <1ms
Insulation resistor: 100MΩ, 100VDC
Overpressure: 1.5 times FS
I would say that it is a typical pressure sensor, the have strain gauge bridge output.
Hence the 2mADC Power Supply???
And the quoted Input and Output Impedances.
They will need a strain gauge amplifier module.
Please note, DO NOT TOUCH THE FOIL PRESSURE SENSING FRONT , the strain gauge is right behind it and any damage will render it useless.
I make industrial depth sensors with these devices, although for industrial use they can be up to 50 times the price,but just as sensitive to mechanical damage.
Tom... 
wclee:
Hi, thanks for the quick reply..My design concept is to assemble pressure sensor, arduino uno and battery. Then put them inside a sphere ball. The ball will roll inside the pipeline and detect leakage based on pressure differential across pipeline. Like what dave-in-nj say, I will need to drill a hole on the surface of sphere ball and place the waterproof pressure sensor outside.
since this sensor is not really suitable for arduino uno. Is there any pressure sensors in the market that fit my concept?
the device you listed was a differential pressure sensor. it has to have a second pressure to use as a reference.
as you probably know Boyle's law will dictate that your 'ball' will need to remain at a constant temperature for the pressure to remain the same.
also, if you expect a lower pressure in the area of a leak, you need to make sure you are applying the correct formulas. Bernoulli's would offer that the speed of movement in the line and the area of the pipe will play an important part in the pressure.
Reynolds numbers will also come into play as the speed increases.
further, since pressure travels at the speed of sound, if there is no flow in the pipe, then the pressure would become nearly constant. large pipe and small hole may not have any pressure changes.
I would offer that with a higher pressure in the pipe, any leakage or flow through the opening would contain all the components of flow, including a sound wave. un-controlled openings are rarely smooth and certainly will not resemble an ASME nozzle, so it will have a component of sound. a second sensor, one for sounds in the frequency range of the fluid viscosity would double your chances of leak detection.
As for a sensor, I would offer that doing the math to see the expected Delta Pressure would be needed in order to find a sensor that can respond to the expected changes. at first guess, I would suspect in the sub 'inch of water' range I would assume less than 0.2 kpa full scale sensor, with a possible leak having a pressure that can be measured in the sub 0.05kpa ranges.
Can the sensor at the link below be used to measure water pressure? Does it compatible with arduino uno? Where can i find the arduino programming code?
wclee:
Does it compatible with arduino uno?
Not directly compatible:
"Output Type: Wheatstone Bridge"
For compatibility get one with a digital interface like I2C(TWI) or SPI like this one:
visit freescale and read some of the documentation they have about their pressure sensors
.http://www.freescale.com/products/sensors/pressure-sensors:DRSNSPRSSR
if your device will be totally enclosed and not have the ability to reference a second pressure, then you cannot use a differential pressure sensor.
read about absolute pressure sensors.
wclee:
Can the sensor be used to measure water pressure?
a 'wet' sensor means that the sensing element may be in contact with a liquid. in all cases, to sense pressure, the sensing element has to be exposed to the thing it is measuring. in some applications, they will add a buffer. a diaphragm or filled cavity so that the harsh environment will not contaminate the sensing device.
make sure your selection is compatible with the fluids it would encounter.
Thanks again for the reply.
Will this sensor as shown in link below fit my criteria?
I just want to measure the the amount of water pressure across the time.
What's the difference between analog and digital output? which one easier for us to read the data?
Can anyone provide the sample arduino code for the sensor (as shown in above link)?
wclee:
Thanks again for the reply.Will this sensor as shown in link below fit my criteria?
I just want to measure the the amount of water pressure across the time.
What's the difference between analog and digital output? which one easier for us to read the data?
Can anyone provide the sample arduino code for the sensor (as shown in above link)?
That sensor can only be used with gases. Figure 4 on page 13 of the datasheet shows you what the various characters in the model number indicate.
v
SSCDANN150PG2A3
^
The "N" in the position shown above, needs to be a "T" or a "V" to be used with liquids.