ITU-T O.41-1994
psophometer使用的电话型电路-规格为测量设备-设备的计量模拟参数(第4研究组)17页
Psophometer for Use on Telephone-Type Circuits - Specifications for Measuring Equipment - Equipment for the Measurement of Analogue Parameters (Study Group 4) 17 pp [Superseded: ITU-T P.53]