What instrument is particularly used for testing ground resistance?

The earth resistance tester is specifically designed for measuring the resistance of the ground, which is critical for ensuring that grounding systems in electrical installations are effective and safe. This instrument applies a small current to the ground and measures the voltage drop that occurs, allowing it to calculate the resistance. It is crucial for applications such as grounding systems in power plants, communication towers, and other facilities where a reliable ground connection is essential for safety and equipment protection.

Other instruments have different functions: a multimeter typically measures voltage, current, and resistance but is not specialized for ground resistance measurements. A clamp-on ammeter is used to measure current in a conductor without needing to make physical contact with the circuit. A battery load tester evaluates the performance of batteries under load but does not relate to ground resistance testing. Therefore, the earth resistance tester is the appropriate choice for this specific requirement.