Measuring circuit for monitoring and testing functionality of a measuring chain

摘要

A measuring circuit which includes an evaluation circuit (13, 63); a sensing circuit (39, 40) having a sensing element (6, 55) configured to generate a measuring signal from a measuring object (7) and a transmission line (26, 69) for transmitting the measuring signal to the evaluation circuit (13, 63); and a test signal injection circuit (21) including a signal injector (12) and an injection line (20) connecting a signal output of the signal injector (12) with the sensing circuit (39, 40) for feeding a test signal into the sensing circuit (39, 40) such that the test signal is transmittable to the evaluation circuit (13, 63) over the transmission line (26, 69). The injection line (20) and the transmission line (26, 69) are advantageously interconnected in series via the sensing element (6, 55) such that the test signal can be fed through the sensing element (6, 55).

主权项

1. A measuring circuit comprising
an evaluation circuit; a sensing circuit comprising a sensing element configured to generate a measuring signal from a measuring object and a transmission line for transmitting the measuring signal to the evaluation circuit; and a test signal injection circuit comprising a signal injector and an injection line connecting a signal output of the signal injector with the sensing circuit for feeding a test signal into the sensing circuit such that the test signal is transmittable to the evaluation circuit over the transmission line; wherein the injection line and the transmission line are interconnected in series via the sensing element such that said test signal can be fed to the evaluation circuit through the sensing element, wherein the injection line and the transmission line are separate from each other except for said series connection via the sensing element, wherein the sensing element comprises at least one feeding pole for injecting the test signal and at least one output pole for delivering at least one of the measuring signal and the test signal; the injection line is connected to at least one said feeding pole to which the transmission line is not directly connected; and the transmission line is connected to at least one said output pole to which the injection line is not directly connected.