Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Publication of BE506296ApublicationCriticalpatent/BE506296A/xx
G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
G01R17/00—Measuring arrangements involving comparison with a reference value, e.g. bridge
G01R17/10—AC or DC measuring bridges
G01R17/16—AC or DC measuring bridges with discharge tubes or semiconductor devices in one or more arms of the bridge, e.g. voltmeter using a difference amplifier
H—ELECTRICITY
H04—ELECTRIC COMMUNICATION TECHNIQUE
H04B—TRANSMISSION
H04B3/00—Line transmission systems
H04B3/02—Details
H04B3/46—Monitoring; Testing
H—ELECTRICITY
H04—ELECTRIC COMMUNICATION TECHNIQUE
H04M—TELEPHONIC COMMUNICATION
H04M3/00—Automatic or semi-automatic exchanges
H04M3/22—Arrangements for supervision, monitoring or testing
H04M3/26—Arrangements for supervision, monitoring or testing with means for applying test signals or for measuring
H04M3/28—Automatic routine testing ; Fault testing; Installation testing; Test methods, test equipment or test arrangements therefor
