What is the benefit of using a hook-on type voltammeter?

The benefit of using a hook-on type voltammeter primarily lies in its ability to measure current safely. This tool employs a non-intrusive method to measure the current flow in a conductor without needing to disconnect or interrupt the circuit. By utilizing the principle of magnetism, the hook-on style clamped around the wire detects the magnetic field produced by the current flowing through it.

This feature is particularly advantageous in environments where safely measuring electrical currents is critical. Technicians can obtain readings while the circuit remains live, reducing the risk associated with handling high voltage equipment. The convenience and safety offered make this type of voltammeter a preferred choice in many electrical troubleshooting scenarios.

The other options discuss functions such as measuring voltage, checking resistance, or measuring frequency, which are tasks that either do not reflect the primary function of a hook-on voltammeter or require different types of testing equipment. Thus, the focus on current measurement highlights why this is the best answer.