**Galvanometer Type Recorders**

Galvanometer type recorders are used in various applications to measure and record electrical quantities. These recorders utilize a galvanometer, which is an instrument used to detect and measure small electric currents. The galvanometer type recorders can be classified into different types based on the type of galvanometer used.

The correct answer is option B - D Arsonal galvanometer. Let's explore this in detail.

**D Arsonal Galvanometer**

The D Arsonal galvanometer, also known as the D'Arsonval galvanometer, is a type of moving coil galvanometer. It is widely used in galvanometer type recorders due to its high sensitivity, accuracy, and linearity. The D Arsonal galvanometer is named after its inventor Jacques-Arsène d'Arsonval.

**Working Principle**

The D Arsonal galvanometer consists of a rectangular coil suspended between the poles of a permanent magnet. The coil is wound with a large number of turns of fine wire, which makes it very sensitive to small currents. When a current flows through the coil, it experiences a torque due to the interaction between the magnetic field of the permanent magnet and the magnetic field produced by the current in the coil.

The coil is connected to a pointer, which moves over a calibrated scale. The angular deflection of the pointer is directly proportional to the current passing through the coil. This allows the D Arsonal galvanometer to accurately measure and record the magnitude of the current.

**Advantages of D Arsonal Galvanometer**

1. High Sensitivity: The D Arsonal galvanometer is highly sensitive and can detect even small currents.
2. Accuracy: It provides accurate measurements due to its linear response.
3. Low Power Consumption: The D Arsonal galvanometer has low power consumption, making it suitable for long-term recording applications.
4. Wide Frequency Range: It can measure a wide range of frequencies, making it versatile in various applications.

In conclusion, the correct answer is option B - D Arsonal galvanometer. These galvanometers are widely used in galvanometer type recorders due to their high sensitivity, accuracy, and linearity.

A galvanometer is an electromechanical instrument used for detecting and indicating an electric current. A galvanometer works as an actuator, by producing a rotary deflection (of a "pointer"), in response to electric current flowing through a coil in a constant magnetic field.