What device provides continuous indication of ground resistance?

The device that provides continuous indication of ground resistance is the clamp-on ground-resistance tester. This specialized tool is designed specifically to measure the resistance of grounding systems while the system is in place and operational. It does this without the need to disconnect the grounding system, making it particularly valuable for ongoing maintenance and monitoring.

While an ohmmeter is capable of measuring resistance, it typically does so in a static or disconnected system, providing a single measurement rather than continuous readings. The other devices mentioned have different functions; for instance, a high-voltage voltmeter is used for measuring voltage, a galvanometer indicates current but does not measure resistance directly, and both are not designed to provide continuous ground resistance measurements. Thus, the clamp-on ground-resistance tester is the best choice for continuous monitoring of ground resistance.