Digital multimeter in LabVIEW?

[butterwaffle]

I am wondering if it is possible to design a digital multimeter using LabVIEW. If so are there any pointers here that anybody can give me? Such as how to convert voltage into current and other things?

[Bob_Schor]

Try asking Google "How does a Multimeter Work?".  You will probably find how a "voltage-meter" can be converted into a "current meter" with an extra part, and how it can also be turned into a "resistance meter" with some additional components.  There are a number of gadgets that interface nicely with LabVIEW (USB 6009, myDAQ, others) that have A/D converters that report voltage.

[butterwaffle]

I know how a multimeter works.. But is it possible to convert voltage to current through LabVIEW? I know how to convert a voltmeter to an ampmeter already. I'm quite confused how you would do it using LabVIEW however.

[RavensFan]

LabVIEW doesn't convert voltage to current or vice versa.  LabVIEW is a software program that has a library of drivers that can read the signals collected by data acquisition devices.  It is the data acquisition device that reads either voltage or current.  What DAQ device do you have?

[butterwaffle]

I have a USB6353

[RavensFan]

That device reads voltage.  You can look in the Example Finder to find an example of how to read a voltage as an analog input.

If you want to measure a current, place an appropriately sized resistor in the current loop and measure the voltage across that.

[moderator1983]

This DAQ card will always gonna read voltage, so if you want to measure the current, probably you can use a resistor (precise and of known value) and allow the current to flow across it and use DAQmx to read the voltage across the resistor and in LabVIEW you can determine the current equivalent to the voltage across resistor (Ohm's law).

There is another option wherein you can use internal shunt resistance (inbuilt in 6353) and LabVIEW will directly give you current readings.

Similarly to calculate Resistance value you need to build an additional circuit arrangement (may be wheatstone bridge or something else)...!!

[butterwaffle]

Oh bummer. So I can't use LabVIEW to make a software program of a DMM then?

[moderator1983]

---

@butterwaffle wrote:

Oh bummer. So I can't use LabVIEW to make a software program of a DMM then?

---

Definitely you can use LabVIEW to make a software application, what you can't do using LabVIEW (alone) is acquiring voltage/current... For voltage/current you need a data acquisition card along with LabVIEW.