| 摘要 |
PURPOSE:To automatically calculate and display the terminal impedance of a cable to be measured by previously storing known terminal impedance and the reflecting level on its end surface and executing operation from said stored value and a measured value for the cable to be measured. CONSTITUTION:Connector 10 and 11 are coupled with each other, a standard core 3 is connected to the coupled connectors and the measurement is carried out under the condition a switch 19 is opened. A pulse generator 1 sends a pulse to the standard core 3 through a hybrid transformer 2 by a signal from a synchronous clock signal generator 14. A reflected wave from the standard core 3 is extracted from the intermediate point of the transformer 2 and stored in a system consisting of a microprocessor 16 and memory 15 through an input attenuator 5, an end surface reflecting level detecting circuit 18, and an AD converter 17. The same measurement as said procedure is carried out under the switch 19 is closed. Subsequently a connector 11' is coupled with the connector 10 instead of the connector 11, a cable 9 to be measured is connected to the coupled connectors and the reflecting level is measured. The measured value is operated on the basis of the data previously measured and stored in the memory 15 to find the terminal impedance of the cable to be measured. |
