​How to Calibrate an Energy Meter on Site?

When conducting on-site current testing of an energy meter, it usually requires waiting for a power outage during maintenance to disconnect the circuit and connect a standard ammeter in series for testing. Alternatively, the meter under inspection can be removed and taken back to the laboratory for testing using a standard source method. Due to the absence of actual strong electromagnetic fields and thermal effects, certain errors that may occur in real-world conditions—such as errors caused by magnetic saturation in current transformers or errors due to self-heating of the electricity meter—may not be fully revealed in such a calibration method.

Therefore, to better evaluate the actual performance of an energy meter and to calibrate it more flexibly without waiting specifically for a power outage during maintenance, you need the device that supports live-load calibration of energy meters. Let me proudly introduce to you Tunkia's Portable Three-phase Energy Tester, TD3250.

Work Principle of TD3250 Portable Three-phase Tester

Real Load Method
TD3250 Portable Three-phase Energy Tester obtains voltage signals through direct parallel connection and utilizes a clamp meter to acquire current signals in a non-contact manner. This enables the synchronous collection of real voltage and current waveforms that are completely consistent with those of the operating electricity meter under test, all without disconnecting the measured circuit. Internally, the instrument functions as a reference meter to calculate standard energy values and performs real-time comparison with the pulses output by the meter under test. It directly computes the relative error of the meter under the actual load conditions, achieving genuine online live-load calibration.

Virtual Load Method

Of course, the TD3250 also supports direct current measurement and is suitable for calibrating single-phase/three-phase voltage sources, current sources, and power sources (specifically 0.05-grade equipment) of class 0.2 or below, both in the laboratory and on-site.

Features of TD3250 Portable Three-phase Tester

• Accuracy: Class 0.02 or 0.05.

• 3PH voltage measurement: 0~576 V.

• 3PH current measurement (direct) : 50 mA~ 12 A.

• 3PH current measurement (clamp) : 100 mA~ 1kA.

• Support electric energy pulse optical/electrical pulse input.

• LCD touch screen.

• Support AC 100 V~264 V wide range supply.

• Support large capacity lithium battery.

• Internal memory, and quickly record test data.

• USB and RS232 interfaces.

• Compact, lightweight, and easy to carry

Function of TD3250 Portable Three-phase Tester

Main Test Items of TD3250 Include:

• Voltage Fundamental Error

• Current Fundamental Error

• Power Fundamental Error

• Energy Fundamental Error

• Wiring Configuration

• Harmonic Distortion

• Waveform Analysis

In addition, TD3250 is also capable of calibrating online AC sampling devices and current transformers (CTs).

Advantages of TD3250 Portable Three-phase Tester

Super Convenience

• Large LCD screen: Color LCD with high brightness, supports touch operation, offering comprehensive functionality that is simple and convenient to use..

• Front panel wiring: convenient for the user to replace the test lead.

• 220 V mains power supply or the lithium battery mode available.

• Built-in large-capacity memory for quickly recording test data of the equipment being tested on-site, capable of storing up to thousands of entries. After calibration is complete, the data can be transferred to the accompanying computer management software.

• The volume is equivalent to the conventional tool box, weighs about 8 kg.

Connection Mode Identify and Graphical Display

• Accurately measure/display the amplitude and phase of voltage and current of each phase.

• Accurately measure the phase between voltage and current of each phase, and visually display them in the form of phasor diagram.

• Automatically identify the actual results of voltage and current, including phase sequence display.

• The trend chart display function of the measuring channel can display the trend change of the measured electricity quantity with time.

• Users can customize single or multiple power waveforms for display.

Data Management

• The equipment can store and manage the test data on site.

• The selected data can be saved to the mobile USB flash disk.

Professional Test Software

• Optional computer-specific testing software can organize and generate test reports from data exported via USB drive, improving testing efficiency.

• Software functionality can be customized according to customer needs, with support for future software upgrades to accommodate new testing requirements.

If you are interested in Tunkia's TD3250 Portable Three-phase Tester, please feel free to contact us.