A.50Hz B.51±0.2Hz C.51±0.5Hz D.51±0.1Hz
A.-0.0005%≤比值差≤+0.0005% B.-0.0001%≤比值差≤+0.0001% C.-0.01%≤比值差≤+0.01% D.-0.001%≤比值差≤+0.001%A
A.±0.02% B.±0.04% C.±0.015% D.±0.03%