Application/Use of 200mV scale in voltmeter

[williame.newtist]

I was wondering what are the uses of 200mV scale in voltmeter? I mean isn't it too small for most applications? but it seems to me every meter has such small scale ,so I was wondering what is their actual usage?

 

[crutschow]

It may be to small for some applications but not all. Many sensors have output voltages much less than 200mV. Offset voltages in op amps are often in the mV region. There are many signal conditions where you need to measure voltages below 200mV. They even build microvolt meters for certain very low signal level applications.

 

[KeepItSimpleStupid]

One useful application is to go to your car when it's working properly and run the engine with all the major accessories on. Light high beam, AC on, Fan on high and measure the voltage from the battery cable at the alternator and the battery cable at the battery.

You just created an uncalibrated current shunt whose voltage is proportional to current. When you suspect the alternator being bad you can perform that test again.

The scale is also useful for determining the voltage drop across connections. e.g. see if a crimp is bad.

Currenr shunts have a millivolt output. 1 mV per amp is common.

Some accessories such as a pressure meter or a thermometer use the mV scale so -30 deg to 212 degrees is easily read in engineering units.

 

[Diver300]

I was wondering what are the uses of 200mV scale in voltmeter? I mean isn't it too small for most applications? but it seems to me every meter has such small scale ,so I was wondering what is their actual usage?

They are often used with a voltage divider. For example, if you want to read +/- 20 V you need a 100:1 voltage divider.

 

[Nigel Goodwin]

I was wondering what are the uses of 200mV scale in voltmeter? I mean isn't it too small for most applications? but it seems to me every meter has such small scale ,so I was wondering what is their actual usage?

Just like analogue meters you use shunts and attenuators to make them read whatever you desire. This way one meter type is all you need, and it can be used for anything you want.

 

[Dean Huster]

On the ACV function, it can be good for checking low audio levels, especially in low-impedance circuits.

I have an active clamp-around current probe that normally uses the 2V range (AC or DC) and is 10 times more sensitive on the 200mV range for reading low currents with better precision.

 

[MrAl]

Hi,


Many 200mv digital meters actually come with voltage divider resistors so you can make your own voltmeter that reads up to 20v, 200v, etc. They used to sell them this way not sure if they do anymore though.

 

[williame.newtist]

Hey guys
you guys are very helpful, Thank you so much!
William