"设备利用系数" can be translated into English as "equipment utilization factor" or "device utilization coefficient".
"Equipment utilization factor" is a more commonly used term in industrial and engineering contexts, referring to the ratio or percentage that indicates how effectively equipment is being used over a certain period.
"Device utilization coefficient" is also acceptable, especially when referring to specific devices or instruments, though it may be slightly less common in general industrial discussions.
Both terms convey the idea of measuring how efficiently equipment or devices are being utilized.