Automatic Transformer Turns Ratio Tester for Accurate Winding Ratio & Polarity Testing

The TRM-200 Precision Transformer Turns Ratio Meter is a fast, accurate, and reliable digital transformer turns ratio tester (TTR) designed for rapid measurement of transformer turns ratio, winding ratio, polarity, voltage, and current in single-phase transformers. Developed for transformer manufacturers, transformer repair facilities, production testing, quality control, laboratories, and field service applications, the TRM-200 provides a simple and dependable method for verifying transformer winding ratios and identifying incorrect connections or winding-related problems.

With 5-digit measurement resolution and a turns ratio measurement range up to 1:1200, the TRM-200 provides precise transformer ratio measurement across a wide range of applications. Its automatic operation, Fast and Precision test modes, 36 V test excitation, automatic HT/LT detection, polarity verification, overcurrent protection, and wrong-connection detection make transformer ratio testing quick, safe, and straightforward.

The compact and portable design makes the TRM-200 suitable for both transformer production lines and field transformer testing, providing technicians and engineers with a practical TTR meter, transformer ratio meter, turns ratio meter, and transformer winding test instrument.

Transformer Turns Ratio Testing

The transformer turns ratio (TTR) is an important parameter used to verify whether the primary and secondary transformer windings have been manufactured according to their intended design ratio.

The TRM-200 applies a controlled AC excitation to the high-voltage (HT) winding and measures the corresponding voltage on the low-voltage (LT) winding. The instrument automatically calculates and displays the transformer turns ratio, allowing the operator to quickly compare the measured ratio with the expected transformer ratio.

Transformer turns ratio testing can help identify:

• Incorrect number of winding turns
• Incorrect winding connections
• Winding faults
• Manufacturing errors
• Shorted turns
• Incorrect tap connections
• Polarity errors
• Abnormal transformer winding conditions

A transformer turns ratio test is commonly performed during transformer manufacturing, routine quality control, commissioning, maintenance, repair, and troubleshooting to verify the relationship between transformer windings. Competitor TTR systems similarly position ratio testing as a way to verify winding condition, ratio accuracy, polarity and connection configuration.

Digital TTR Meter for Transformer Ratio Measurement

The TRM-200 is a digital TTR meter designed to replace slow and complicated manual transformer ratio measurement methods with an automatic digital test procedure.

The instrument provides a direct numerical display of the measured ratio, reducing operator calculation and improving test efficiency.

With its 5-digit resolution, the TRM-200 provides detailed measurement of the transformer winding ratio and allows operators to identify small variations between the expected and measured ratio.

The instrument is suitable for testing:

• Small power transformers
• Control transformers
• Distribution transformers
• Single-phase transformers
• Industrial transformers
• Instrument transformers within the applicable measurement range
• Transformer prototypes
• Production transformer samples
• Repaired transformer windings

Transformer Polarity Testing

In addition to transformer turns ratio measurement, the TRM-200 provides transformer polarity testing.

Correct transformer polarity is essential when connecting transformer windings and when transformers are used in electrical systems requiring correct phase relationships.

During the test, the TRM-200 analyzes the relationship between the applied HT excitation and the corresponding LT response and verifies the polarity of the transformer winding.

The instrument therefore combines turns ratio measurement and polarity verification in one test procedure, helping reduce incorrect transformer connections and improving production-test reliability.

Transformer Ratio Measurement up to 1:1200

The TRM-200 provides transformer turns ratio measurement up to 1:1200, making it suitable for a wide range of single-phase transformer applications.

The wide ratio measurement capability allows manufacturers and service technicians to test transformers with substantially different primary-to-secondary voltage ratios without changing to a separate measuring instrument.

The high-resolution digital measurement makes the TRM-200 suitable for transformer production testing, quality inspection, laboratory verification, repair and maintenance.

Transformer Turns Ratio Tester for Quality Control

The TRM-200 is particularly useful for transformer manufacturing quality control.

During production, the transformer turns ratio can be checked after winding and assembly to verify that the manufactured transformer corresponds to the intended electrical design.

Routine TTR testing can be incorporated into production inspection procedures for:

• Winding verification
• Transformer assembly inspection
• Final product testing
• Incoming material verification
• Batch quality control
• Production process verification
• Repaired transformer inspection

The fast automatic measurement process helps manufacturers perform repeated transformer ratio tests while reducing manual calculations and operator-dependent errors.