# what does mV/V mean?

• posted

Before I order some expensive pressure sensors, I have a trivial question (just to make sure):

The specs read: Excitation voltage 10Vdc,24Vdc(8-36Vdc) Output options: 1.5mV/V, 2mV/V, 2.5 mV/V, 3.33 mV/V,4-20mA,0-10V,0-5V,0-20mA

What does mV/V mean?

Thanks, Mike

• posted

Simple :) it is a 4 resistor bridge sensor. If you supply the bridge with 1 volt , it outputs the given number of millivolts for full range signal. So if the bridge allows 10 volt supply, you get 10 times the specified Millivolts.

• posted

Ok, you have 1V across the widgit, and you stress the widgit, and it gives you say a reading of 5mV

do the identical with 3v across the widget and it will give you 3 times ie 3/1 the voltage, so15mV

martin

• posted

You mean that for the 1.5mV/V option the sensor spits 15 mV at full scale pressure while on a 10V excitation? Isn't that a too noise-prone voltage for full scale?

Mike

• posted

Welcome to the world of sensors---15mV is a princely voltage here. The world would beat a path to the door of someone with a clever idea for a stress sensor (or temperature sensor or...) directly giving large voltages.

For example, a typical thermocouple voltage is 3-5 mV/K.

• posted

Yep, thats just it, and no, there is no noise problem,its a rather low impedance voltage floating differential output. So you need a differential amplifier for the bridge output. Better buy the sensor with a buildin amp, if they sell it.

• posted

Yep, thats just it, and no, there is no noise problem,its a rather low impedance voltage floating differential output. So you need a differential amplifier for the bridge output. Better buy the sensor with a buildin amp, if they sell it.

• posted

More like 10-50uV/K for the common types.

• posted

it means 1/1000 or 0.001 obviously.

In this instance it means that for an input voltage of X you get an output voltage of Y = X x scale factor in mV/V

Graham

• posted

Right.

Not with good signal conditioning and A/D conversion. A load cell can put out 30 mV full scale and weigh things to 0.01% accuracy and linearity.

John

• posted

Hello Mike,

That's why we analog guys will always have something to do :-)))

15mV is actually a lot.
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Regards, Joerg

http://www.analogconsultants.com```
• posted

"siliconmike" schreef in bericht news: snipped-for-privacy@m73g2000cwd.googlegroups.com...

15mV is plenty, and it comes from a pretty low impedance. Noise is not a big problem, there are not very high frequencies to be expected in a pressure sensor, so you can filter plenty.
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Thanks, Frank.
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• posted

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