Watts, Amps, Volts, what is "U"?

[Circlotron]

On my Rigol DS2072 there is a setting to change the vertical units. See pic. What is "U"? Arbitrary units?
 

[Fungus]

"Unspecified" - you're doing something that doesn't have a name.

[mairo]

I believe U and V is the same thing - potential difference. In some countries in Europe U is potential diference - example: U = I*R, units are still in 'V'

[Neganur]

I believe U and V is the same thing - potential difference. In some countries in Europe U is potential diference - example: U = I*R, units are still in 'V'

Not in this case. It's units, the scope doesn't list I, P it lists W, A, V so clearly units. U is not a unit in Europe either.

[DG5SAY]

On my Rigol DS2072 there is a setting to change the vertical units. See pic. What is "U"? Arbitrary units?

Perhaps "User defined" and another menue item is shown when "U" is selected?

[MosherIV]

Hi

I was going to be flippant and say 'read the manual' but then I just checked the manual and it really does not say 

Total Fail 

[newbrain]

What U decide, of course.

  Now I feel silly. But someone had to do it

[technogeeky]

It's U for Units. As in, Arbitrary Units.

[tautech]

It's U for Units. As in, Arbitrary Units.

OK, so how does that work with 1, 2, 5 attenuation steps on the vertical axis and why is it needed? 

[gamalot]

Don't look at me, I am Chinese, but there is nothing different in Chinese version of user manual!   

[raptor1956]

I noticed when using a Rigol DP832 power supply to charge an 18650 cell that when the cell voltage was relatively low the display indicated CC for constant current and shortly after reaching the voltage setpoint the display then switched to CV for constant voltage.  In the few seconds between them it displayed UR which the manual calls "critical mode". 


Brian

[technogeeky]

It's U for Units. As in, Arbitrary Units.

OK, so how does that work with 1, 2, 5 attenuation steps on the vertical axis and why is it needed? 

Well, an oscilloscope measures voltage of course, so it's really volts. But just like the Amps setting, if you are measuring something (say, millivolts) which is proportional to something else (say, amps), you can change the unit.

Same with U, but for any kind of units. Temperature. Height. Speed. Etc.

[JFJ]

What is "U"? Arbitrary units?

It's just a label that, according to the DS2000 series Programming Guide, stands for "Unknown":

[dom0]

I noticed when using a Rigol DP832 power supply to charge an 18650 cell that when the cell voltage was relatively low the display indicated CC for constant current and shortly after reaching the voltage setpoint the display then switched to CV for constant voltage.  In the few seconds between them it displayed UR which the manual calls "critical mode". 

Likely stands for unregulated. Maybe a transient oscillation in the CC-CV crossover region, or just a software glitch.

[MK14]

I believe U and V is the same thing - potential difference. In some countries in Europe U is potential diference - example: U = I*R, units are still in 'V'

I agree.

U = Voltage, due to some foreign languages use U instead of V (I believe). Somehow I thought it was German (U), but it seems it was different countries. (I'm probably wrong here, it seems it is more likely that the U is because Physics uses it for Potential Energy (U), Source: http://whatis.techtarget.com/definition/potential-energy-U).

DEFINITION
potential energy (U)

The potential energy is stored when an elastic is stretched, and converted to kinetic energy when the elastic is released. Other types of potential energy include chemical, which is related to the formation of chemical bonds and electrical, expressed as voltage

The following article explains it in more detail, but I knew about it anyway.

https://en.wikipedia.org/wiki/Voltage

Voltage, electric potential difference, electric pressure or electric tension (formally denoted ?V or ?U, but more often simply as V or U

But there are other sources as well, such as:
http://www.thefreedictionary.com/potential+difference

potential difference
n
(General Physics) the difference in electric potential between two points in an electric field; the work that has to be done in transferring unit positive charge from one point to the other, measured in volts. Symbol: U, ?V or ?? Abbreviation: pd Compare electromotive force

Third/Fourth and hopefully last source needed:
http://www.utm.edu/staff/cerkal/potential.html

Electric Potential Energy (U) and Electric Potential (V): (Notes from C. Erkal’s lectures PHYS 221)

I hope I have included enough sources, but there are more, if wanted.

EDIT: But Rigol, may intend the U to mean something else, such as Umbrella, Unijunction Transistor or Unwell . It is possible that Rigol use the U to mean something else, but I would suspect it is just an alternative to 'V'.

[dom0]

Don't confuse symbol and unit. U is (esp. in Europe and even more esp. in Germany) the symbol of a (specific: like between two points in a circuit, or the output of a circuit) voltage, but the unit is V(olts) regardless. Similarly I is often used as the symbol for a current, while the unit is still A(mperes). IOW symbols (=variable + unit) are variables or names for physical quantities (=number + unit).

[Circlotron]

So I is expressed in Amps
and U is expressed in Volts.