Choosing the right contact resistance tester depends on your specific application, testing environment, and required accuracy. Here are some key factors to consider:

1. Measurement Range

• Assess the Resistance Range: Determine the typical resistance values you’ll need to measure. Contact resistance testers often measure in the micro-ohm (μΩ) range, suitable for low-resistance connections.
• Consider Accuracy Requirements: If you need very precise measurements, look for a tester with a high degree of accuracy, often listed in terms of a percentage of the reading.

2. Test Current Range

• Evaluate the Current Levels Needed: Contact resistance testers vary in the amount of current they use to make a measurement, typically from a few milliamps to over 100A. Higher currents are better for measuring low resistances and may give more stable readings.
• Match the Current to Your Application: High-current testers are often used in applications with high power connections, such as circuit breakers or busbars. For smaller or sensitive components, lower current might be more appropriate.

3. Portability and Power Source

• Look for Portability if Needed: If you’ll be doing fieldwork, a portable tester with a sturdy build is essential. Handheld or lightweight models can be convenient.
• Battery Life or Power Supply: If you need to work in remote areas, long battery life or the ability to connect to an external power source is important.

4. Data Logging and Connectivity

• Data Storage: For applications that require documentation, choose a tester that can store or log multiple readings.
• Connectivity Options: Some testers come with USB, Bluetooth, or other connectivity options, which make it easier to transfer data to a computer or other devices for analysis or reporting.

5. Ease of Use and Interface

• User-Friendly Interface: Look for models with clear displays, intuitive buttons, and simple navigation, especially if the tester will be used by multiple operators or people with varied skill levels.
• Automated Features: Some testers offer automatic temperature compensation, averaging, or zeroing functions, which can make measurements faster and more reliable.

6. Environmental Suitability

• Operating Conditions: If your testing involves extreme environments (high humidity, high temperature, or outdoor work), choose a model that is rated for those conditions. Some testers have rugged cases or are designed to resist dust and moisture.

7. Durability and Quality

• Build Quality: Look for a reputable brand with a good warranty, as well-built devices will likely offer greater longevity and reliable performance.
• Safety Features: Make sure the tester has adequate safety features, such as overload protection, especially if it will be used on high-voltage equipment.

8. Calibration and Maintenance

• Calibration Options: Check if the tester can be easily calibrated and whether calibration services are available.
• Ease of Maintenance: Consider whether the tester has replaceable parts, like test leads, and if servicing it would be convenient if needed.

9. Budget and Cost of Ownership

• Balance Price and Features: Higher-end models come with advanced features but can be costly. Decide which features are essential and avoid paying for options you don’t need.
• Consider Total Cost: Some testers may require frequent calibration or costly accessories, so consider the long-term costs of ownership.

10. Specialized Needs

• High-Current Testing: For heavy-duty applications like testing large circuit breakers, a tester capable of handling high currents (100A+) is essential.
• Low-Inductance or Short-Duration Testing: For inductive loads, a tester with pulse testing or short-duration current capabilities can help avoid long wait times and improve safety.

When choosing a contact resistance tester, match the technical specifications with your specific application. Prioritize accuracy, durability, ease of use, and any features that can streamline data handling or increase reliability in your typical testing environment.

Contact resistance tester TEHL Series outputs DC 600A/400A/200A/100A current to test the contact resistance of circuit breaker or high current cable contacts. It is designed according to IEC62271. The main application of the tester is the measurement of circuit breaker contact resistance.