Which sensor output is better when length of signal wire reaches upto 2 meters?

[Megahertz]

I have a choice between 2 sensors, one outputs voltage 0.5-4.5v and one outputs current 4-20mA. The cable carrying the signal could reach upto 2 meters. Which output type would be better in this case?

Also not related to the above question, if a sensor has 4-20mA output, how does a MCU reads it, as far as I know MCU can read voltages easily. How can current be measured my MCU?

[mackrackit]

Two meters should not be a problem with either one.

Here is how to do the conversion.
http://www.omega.com/techref/das/4-20ma.html

[Heckler]

Mackrackit is correct and the weblink he provided give a good example of how to convert current to voltage.

I would just like to add...

The reason that current loops are used (like 4-20ma) is to remove the uncertanty of wire resistance in long runs.

example: let's say the sensor is measuring temperature (or flow, or mass or light level, etc. etc.) and that 20 deg equals 10ma.

If the connecting wire is short the sensor uses what ever voltage required to push 10ma through the loop.
If the connecting wire is 2,000 feet long and thus more resistance (assuming the same wire gauge) then the sensor increases the voltage just enough to maintain the 10ma of current through the loop.

Sensors of this type will list a maximum resistance for which they can drive the 4-20 ma current through.

regards

[Megahertz]

Thanks a lot.