dBu dBm 這兩個(gè)單位通常用于音頻輸入等小信號(hào).
dBm refer to 1 milliwatt in the selected impedance.
dmu refer to 0.7746V(1mW @ 600 Ohm load)

謝謝,那dbu和dbm到底是電壓?jiǎn)挝贿€是功率單位?the selected impedance是指測(cè)試時(shí)串接在探棒上的阻抗嗎?

dB只是比值, 沒(méi)有量綱
0 dBm = 1毫瓦(對(duì)應(yīng)功率的比值)
selected impedance 是指選定的負(fù)載,負(fù)載不一樣,功率為1毫瓦時(shí)的電壓也不一樣

0 dBu = 0.7746V(負(fù)載為600 Ohm時(shí)的1毫瓦輸出功率, 對(duì)應(yīng)電壓的比值)
使用dBu時(shí),負(fù)載電阻必須定為600 Ohm