How Current Coils Work in Calibration

What is a Current Coil?

A current coil is a component made by winding a conductive wire through which electric current flows. It is widely used in power measurement, control, and calibration systems. Its primary functions include carrying current, generating magnetic fields, or inducing current.

While its specific function may vary across different devices, the underlying principle remains the same: either generating a magnetic field from current flow or inducing a current from a magnetic field.

Current coils can function as standalone devices—used in conjunction with standard current sources—or be integrated into instruments such as energy meters, current transformers, and relays as critical functional components.

Working Principle and Applications

1. Generating Magnetic Field When Energized

According to Ampere’s circuital law, when current  flows through a coil, a magnetic field  is generated around it. The strength of this field is proportional to the current and the number of turns :

B ∝I×N

2. Magnetic Field Induction or Activation

In measurement devices: The magnetic field is sensed by other components and converted into voltage, current signals, or mechanical action.

In calibration or reference applications: The coil generates a known and stable magnetic field for reference measurement.

Introduction to TD1020 Current Coil

TD1020 is a series of multi-turn current coils designed based on the ampere-turn equivalence principle. It is used together with the TD18 series standard current sources to calibrate clamp meters with accuracy class 1 or lower.

Example Application

Imagine you want to calibrate a clamp meter rated for 1000 A, but your test setup can only provide 10 A. By using a 50-turn TD1020 coil, the clamp meter can sense an equivalent 500 A field due to magnetic flux multiplication:

Equivalent Current = Turns × Actual Current

For example:

·Actual current = 10 A

·Turns = 50

·Equivalent current sensed = 500 A

This allows high-current simulation under low-current conditions, improving safety, efficiency, and cost-effectiveness for lab or on-site applications.

Technical Specifications

Key Advantages

✅ Low-cost simulation of high-current conditions: Safe and efficient

✅ Portable and convenient for lab or field use: Compact and easy to transport

✅ High calibration efficiency: Ideal for batch calibration of various clamp meters

✅ Full portable calibration solution: Works seamlessly with the TD18 standard source series to provide a stable reference magnetic field

If you want to know more, please feel free to contact us.