dBm

Decibels referred to 1.34 x 10-9 hp or 5.69 x 10-8 Btu/min (one milliwatt), which flows always in the same direction. Further classifications of direct currents are: 1) continuous currents which are steady, non-pulsating direct currents. 2) constant currents, which continue to flow for a con­siderable time in the same direction and with unvarying intensity. 3) pulsating currents, which are regularly varying con­tinuous currents.