230V/240V Question

[EFLImpudence]

The OED appears to given definitions of both "at this moment" (the "no. 1" definition) and " a little time ago", without any references to Scotland.

Do you think they are correct?

 

[stillp]

In Wenglish it sometimes means "soon".

 

[stillp]

No, because if the frequency were not mentioned, the voltage tolerance could not be measured precisely and repeatably.

I'm afraid that I don't understand.

Neither do I. I have equipment here which can accurately measure AC voltage from a few Hz up into the GHz range. What's so difficult about measuring voltage a little way either side of 50Hz?

Nothing.

 

[stillp]

John, PBC, what is the boiling temperature of water?

 

[PBC_1966]

Nothing.

Then I'm still confused as to what you meant by this:

No, because if the frequency were not mentioned, the voltage tolerance could not be measured precisely and repeatably.

 

[EFLImpudence]

John, PBC, what is the boiling temperature of water?

Please Sir, I know.

 

[PBC_1966]

John, PBC, what is the boiling temperature of water?

212 deg. F / 100 deg. C at standard (sea-level) atmospheric pressure.

 

[EFLImpudence]

...but the pressure varies even at sea-level.

 

[stillp]

Thank you PBC. How would you ensure repeatable measurements if the pressure were not specified?

 

[JohnW2]

The OED appears to given definitions of both "at this moment" (the "no. 1" definition) and " a little time ago", without any references to Scotland.

Do you think they are correct?

I really don't know. It's not an expression I personally use, or often hear - other than from Scottish people in which case it seems to have the 'Scottish' meaning you have indicated.

Kind Regards, John

 

[JohnW2]

Thank you PBC. How would you ensure repeatable measurements if the pressure were not specified?

This really has nothing to do with what we are discussing. By asking about the boiling point of water you are talking about something which is dependent on something else (pressure). The AC potential difference measured between two points (such as the two conductors of a supply) is in no way dependent on the frequency of that voltage - so it can be measured as accurately and 'repeatably' as one's equipment allows without any knowledge of, or reference to, the frequency - even if that frequency is varying.

Kind Regards, John

 

[PBC_1966]

Thank you PBC. How would you ensure repeatable measurements if the pressure were not specified?

Repeatable in what sense? The water will boil at some specific temperature whatever the pressure, even though that temperature will vary with pressure. The fact that the pressure has altered doesn't affect the accuracy of the temperature measurement taken, it's just that the water is boiling at a different temperature.

In the same way, while a badly bogged down network which results in a severe drop in supply frequency might well also have the consequences of below-normal voltages, the change in frequency doesn't affect the accuracy with which those voltages may be determined.

 

[JohnW2]

...but the pressure varies even at sea-level.

It does, but "Standard Atmospheric Pressure" (indeed, also "Standard Temperature and Pressure", STP) is defined, and does not vary. However, as I've just written the boiling point of water is totally non-analogous with electricity supply voltage measurements.

Kind Regards, John

 

[JohnW2]

Then I'm still confused as to what you meant by this:

No, because if the frequency were not mentioned, the voltage tolerance could not be measured precisely and repeatably.

Me too.

Kind Regards, John

 

[EFLImpudence]

...but the pressure varies even at sea-level.

It does, but "Standard Atmospheric Pressure" (indeed, also "Standard Temperature and Pressure", STP) is defined, and does not vary. However, as I've just written the boiling point of water is totally non-analogous with electricity supply voltage measurements.

So PBC was wrong, then.