By the use of multipliers the range of voltmeters may be increased to any practical limit.
The sensitiveness of this instrument is such that it may be substituted in numerous cases for the non-portable reflecting type of galvanometer; as for instance, in the checking of ammeters and voltmeters to an accuracy of .
A multiplier is of considerable value in that it does away with the necessity of having a number of voltmeters of different ranges.
Milli-ammeters or milli-voltmeters are instruments in which the scale is graduated to read directly in thousandths of an ampere or thousandths of a volt respectively.
According to the principle of operation, ammeters and voltmeters are classified as: 1.
As actually constructed, most voltmeters are simply special forms of ammeter.
The voltmeters and wattmeters are provided with a contact key which may be locked in position, enabling the instruments to be left constantly in circuit.
The voltmeters and wattmeters are constructed on the dynamometer principle and the ammeters, on the magnetic vane principle.
Ammeters to measure the volume, and voltmeters to determine the pressure of current supplied to the baths, should also be provided.
The attraction (or repulsion) in electrostatic voltmetersis proportional to the square of the volts.
Three voltmeters are required, and accordingly the method is sometimes called the three voltmeter method.
When both voltmeters read the same, that is, when the virtual pressure of the alternating current is the same as the direct current pressure, the heating effect is of course the same.
Magnetic vane movement of a Wagner instrument; it is used both forvoltmeters and ammeters.
When wound with fine wire~ and used in connection with properly wound resistances, it is equally useful for measuring alternating pressures, and may thus be employed to calibrate alternating current voltmeters as well as ammeters.
It is desirable, in any system of distribution, to read the active voltage at the point of distribution, by means of the voltmeters in the station.
That is why voltmeters of this kind are made out of a long piece of fine wire or else have a coil of fine wire in series with the current-measuring part.
Footnote 11: If you can afford to buy, or if you can borrow, ammeters and voltmeters of the proper range you should take the characteristic yourself.
The ammeters and voltmeters which we use for the measurement of audion characteristics and the like are usually electromagnetic instruments.
The hardened steel pivots used in all high grade voltmeters are ground and polished with extreme care so as to secure and maintain a high degree of sensitiveness.
One voltmeter is sufficient on the board if a proper switching device be employed to shift its connections across either of the two circuits; otherwise, two voltmeters will be necessary, one bridged across each of these respective circuits.
How are station voltmeters usually attached to the switchboard?
How many voltmeters are required for the two phase system?
Voltmeters are removed and the armature short circuited with the ammeters in circuit.
The necessary ammeters, voltmeters and wattmeters for adjusting the loads on the motors and generator are shown in above figure.
The difference between the design of direct currentvoltmeters of different capacities lies simply in the high resistance joined in series with the fine wire coil.
What attachment is sometimes provided on station voltmeters used for constant pressure service?
Why do station voltmeters indicate a voltage slightly lower than actually exists across the leads?
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "voltmeters" in a variety of sentences. We hope that you will now be able to make sentences using this word.
