Abstract: A system tests a repeating installation having transmitter-receivers (3, 4) and a line controller (2). The system includes the repeating installation to be tested, a first tester (10), a second tester (11), an input unit (12) for entering a first virtual network into the first tester (10), an input unit (13) for entering a second virtual network into the second tester (11), and a line control table which is provided for the transmitter-receiver (3) and into which the destination transmitter-receiver (4) is written according to address information added to the data input to the transmitter-receiver (4). Test data transmitted from the first tester to the virtual network of the second tester is received by the second tester, and the received test data is examined. This greatly reduces facility costs and installation space and realizes performance evaluation of a repeating installation under a large-scale network environment.

Abstract: A nuclear magnetic resonance spectrometry is disclosed in which a 90.degree. pulse and a 180.degree. pulse are applied to nuclei under observation at a time interval of t. Then, the resulting echo signal is observed after a period of t. Either a strong 90.degree. pulse of strong RF waves are applied to nuclei that are not observed. The strong RF waves decouple the nuclei not observed over a broad range. The application of the strong 90.degree. pulse or RF waves is initiated in synchronism with the 180.degree. pulse. The application of the RF waves are terminated before the beginning of the observation of the echo signal. The observation made in this way makes it possible to obtain spectra of quaternary carbons, the spectra including the information about long-range coupling.