Megger TOS1 Transformer Ohmmeter Standard

Overview

The Megger TOS1 is a high-accuracy reference resistance standard used to calibrate and verify transformer ohmmeters and winding-resistance test instruments. It gives test laboratories and field engineers a dependable way to confirm that a resistance tester is reading correctly, either as a bench calibration reference or as a rugged, portable check standard carried to site alongside the instrument being verified.

With a specified accuracy of ±0.1% and a four-terminal (Kelvin) connection that removes the need for lead compensation, the TOS1 provides a stable, traceable resistance value that is independent of test-lead resistance. It is designed as a universal standard for use with any ohmmeter and accepts large test clips or banana-jack inputs, so it works with single-phase and three-phase winding-resistance testers (three-phase instruments are checked using their single-phase excitation method). Its rugged construction makes it equally suited to laboratory and field use.

Key Features

• High-accuracy ±0.1% reference resistance standard for ohmmeter calibration and verification.
• Four-terminal Kelvin connection — no lead compensation required.
• Universal standard for use with all single-phase and three-phase transformer ohmmeters.
• Accepts large test clips or banana-jack inputs for easy connection.
• Rugged design suitable for both laboratory calibration and portable field checks.
• Provides a stable, traceable reference for winding-resistance test programmes.

Applications

• Calibrating and verifying transformer ohmmeters and winding-resistance testers.
• Laboratory reference resistance for periodic instrument calibration.
• Portable field check of resistance testers before or during a test campaign.
• Quality assurance of winding-resistance measurements in transformer testing.

What’s in the Box

• TOS1 Transformer Ohmmeter Standard.
• Connection terminals for test clips / banana jacks.
• Carrying case and user documentation / calibration certificate.

Exact contents may vary by order; contact MME to confirm your configuration.

Why buy from MME in UAE

MOHAMMAD MAHDI Electronics Trading LLC (MME) is a trusted supplier of Megger test and measurement equipment across the UAE and the wider Gulf region. We offer genuine Megger products, competitive pricing, expert application support and reliable after-sales service to keep your calibration and testing programme running smoothly.

Download the Megger TOS1 datasheet