FREQUENCY METER [SURDHI]

The Surdhi is an analogue vibrating reed-type frequency meter manufactured by SURDHI . It is designed for flush-mounting on industrial control panels, generator sets, and switchgear to monitor power supply frequencies.
A frequency meter is an electronic or electromechanical instrument used to measure the frequency of a periodic electrical signal, typically expressed in Hertz (Hz) (cycles per second). They are critical in alternating current (AC) power networks to ensure power grids, generators, and industrial machinery run at stable, safe speeds.

• Frequency Range: Must match the system frequency. Standard power grid models operate. Laboratory RF models can measure up to gigahertz.
• Operating Voltage: The internal coils or digital circuits must withstand the system voltage, commonly AC.
• Accuracy Class: Indicated as a percentage of the full-scale value (e.g., Class \(0.5\) or Class \(1.0\)). Lower numbers indicate higher accuracy.
• Burden (Power Consumption): Measured in Volt-Amperes representing how much electrical load the meter puts on the system it is monitoring. Low burden is preferred.

• How it works: These utilize balancing circuits, such as electrodynamometer or ratiometer systems. They balance the current passing through a purely resistive circuit against a frequency-dependent inductive or capacitive circuit. The resulting pointer deflection indicates the exact frequency on a dial.
• Key advantage: Provides a continuous, real-time reading across the scale.