Why start the comparison with SC680
DC jaw-current measurement and a swivel head distinguish SC680 from narrower models. Those features are worthwhile when the systems and access conditions call for them, not because the broadest specification is always best.
Read smaller models on their own terms
SC260, SC440 and SC640 cover different carrying and measurement choices. Use the actual documented inrush and current capabilities rather than treating similar model names as interchangeable.
Keep measurement and authorization separate
Choose the instrument and leads for the electrical environment and follow the required qualified-work process. A clamp meter is not a universal substitute for isolation verification or another instrument required by the job.
