What is Galvanometer: Definition and 56 Discussions

A galvanometer is an electromechanical measuring instrument for electric current. Early galvanometers were uncalibrated, but improved versions, called ammeters, were calibrated and could measure the flow of current more precisely.
A galvanometer works by deflecting a pointer in response to an electric current flowing through a coil in a constant magnetic field. Galvanometers can be thought of as a kind of actuator.
Galvanometers came from the observation, first noted by Hans Christian Ørsted in 1820, that a magnetic compass's needle deflects when near a wire having electric current. They were the first instruments used to detect and measure small amounts of current. André-Marie Ampère, who gave mathematical expression to Ørsted's discovery, named the instrument after 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.
Galvanometers have been essential for the development of science and technology in many fields. For example, in the 1800s they enabled long-range communication through submarine cables, such as the earliest transatlantic telegraph cables, and were essential to discovering the electrical activity of the heart and brain, by their fine measurements of current.
Galvanometers have also been used as the display components of other kinds of analog meters (e.g., light meters and VU meters), capturing the outputs of these meters' sensors. Today, the main type of galvanometer still in use is the D'Arsonval/Weston type.

View More On Wikipedia.org
  1. J

    Galvanometer Spring Weakness and Current Adjustment

    Hi; Could someone please help me with the following question: If the restoring spring of a galvanometer weakens by 26.4% over the years, what current will give full-scale deflection if it originally required 36.8uA? Thanks for your help.
  2. S

    Finding Magnetic Field in a Square Coil with Tangent Galvanometer

    Hey, I was wondering how would you find the value of the magnetic field inside a square coil? My books talk about finding the value of the mag. field at the center of a circular coil and everytime I search google for galvanometers made with square loops, I only find information on circular...
  3. S

    Rectangular coil in a galvanometer

    Good day everyone, I was wondering how would you determine the magnetic field within a square coil? My colleague and I are trying to write a lab up on tangent galvanometers, but all we can find are models with circular coils, and ours is square. Any help is appreciated.
  4. C

    Tangent Galvanometer and others

    Why is it that in a tangent galvanometer the aluminium pointer is fixed perpendicular to the magnetic needle and not parallel? Anyways , why is the aluminium pointer used after all can't we just measure the current by the defletion of the needle ? There is a statement that says "In a...
  5. U

    How Does Moving a Magnet Near a Coil Demonstrate Lenz's Law?

    In physics class today, we did a project that I don't quite understand. We layed a small 50-turn coil flat on the table and held a magnet in a vertical position near the coil. We had the Galvanometer hooked up to make a clockwise current. The class then moved the magnet close to the coil and...
  6. E

    Troubleshooting Galvanometer Problems and Calculating Resistance | Expert Tips

    I figured out the capacitor/charging problem that I last posted. Here's my latest cause of worry: 1)The Resistance of the coil of a pivoted-coil galvanometer is 7.92 Ohms and a current of .0194 A causes it to deflect full scale. We want to convert this gavanometer to an ammeter reading 10 A...
Back
Top