The REAL difference between a Galvanometer and an Ammeter

[jaumzaum]

Hello guys.
I'm having some trouble to understand the real difference from the Galvanometer and the Ammeter.
The best comment I saw in some forum was:
Ammeter: ANY instrument used to measure electrical current
Voltimeter: ANY instrument used to measure voltage difference
Galvanometer: a PARTICULAR instrument that uses the deflection of a magnet in a electric field to move a needle and measure low current and voltage.

I would agree to that explanation if the only type of galvanometer that exists was the D'Arsonval type. But, searching online, I found that there are other types of Galvanometer, like the Astatic, the Mirror, the Ballistic, the Thermo, the Vibation and the String Galvanometer. So my question is, what ALL these devices have IN COMMON that make them all be called for the name Galvanometer.

Also, I know some Ammeters are made from a Galvanometer and a Shunt resistance, connected in parallel to the Galvanometer and in series with the circuit, and some Voltmeters are made from a Galvanometer and some big resistance that is connected in series with the Voltmeter and both in parallel to the circuit. The second question is: What are some other types of Ammeters and Voltmeters that are not build from a Galvanometer?

 

[BvU]

the real difference

It's not concrete (the building material variety), it's language. Galvanometers are harder to calibrate, less rugged and I 've never (well, not for a few decades) seen one outside an educational environment.

What are some other types of Ammeters and Voltmeters that are not built from a Galvanometer?

The digital variety comes to mind

 

[berkeman]

What are some other types of Ammeters

There are Hall Effect clamp-on probes for measuring AC and DC currents (they are connected to a voltmeter device or oscilloscope for readout):

https://images-na.ssl-images-amazon.com/images/I/71VHrqdgMLL._SL1500_.jpg

And there are Current Transformers for measuring AC currents (they generally are connected to a "burden resistor" and a voltmeter device for readout, or connected a an ammeter if there is no burden resistor):

https://i1.wp.com/sentrancorp.com/wp-content/uploads/2019/03/LN2F-Front.62.jpg?fit=404%2C323

 

[Tom.G]

An excerpt from https://en.wikipedia.org/wiki/Galvanometer. There are several hotlinks, images, and variations in the original article.

Galvanometers developed from the observation that the needle of a magnetic compass is deflected near a wire that has electric current flowing through it, first described by Hans Christian Ørsted in 1820. They were the first instruments used to detect and measure small amounts of electric currents. André-Marie Ampère, who gave mathematical expression to Ørsted's discovery and named the instrument after[1] the Italian electricity researcher Luigi Galvani, who in 1791 discovered the principle of the frog galvanoscope – that electric current would make the legs of a dead frog jerk.

See also https://en.wikipedia.org/wiki/Luigi_Galvani

Cheers,
Tom

 

[sophiecentaur]

real difference from the Galvanometer and the Ammeter.

The word "real" should make you suspicious - particularly if you happen to be reading an eBay advert. As far as I am concerned, Galvanometer implies 'sensitive'. If I wanted to be sure that an instrument was an actual galvo (as I would recognise it), then I would want to read the spec.
The words used to describe things can vary with fashion and with salestalk.

 

[jaumzaum]

An excerpt from https://en.wikipedia.org/wiki/Galvanometer. There are several hotlinks, images, and variations in the original article.

See also https://en.wikipedia.org/wiki/Luigi_Galvani

Cheers,
Tom

Thanks Tom, I actually had already read the first article entirely, and in part it's because of it that I'm posting this question. Even wikipedia does not give a satisfactory real distinction from a Galvanometer to an Ammeter, or a satisfactory definition of what a Galvanometer is. They also gave me a lot of examples of other Galvanometers (in "realted links") that for me does not have anything in common.

@sophiecentaur thank you for the response. I am not trying to buy a Galvanometer. It's only for didactic purposes. I want to know if there are a real definition that ALL the previous types of Galvanometers I mentioned above would have IN COMMON, or if it's just a historical/language thing.

 

[sophiecentaur]

I am not trying to buy a Galvanometer. It's only for didactic purposes.

Yes, I realize that but my post was an attempt to see this in the right proportion. It really is not very important what you call a galvo and there are more useful things to teach students, when the situation seems to be that there is no actual official definition of the word. If that's made clear to students and if they learn to look at the spec of a piece of equipment then they can't go far wrong.
Uncertainty in naming or defining a galvanometer is only one example of regional / cultural and historical uses of words. Lesson - when in doubt give extra qualification in any description. Engineering has gone beyond 'the naming of parts', so don't worry.