| 摘要 |
<p>A device for measuring the concentration of two substances through the transmission of electromagnetic waves. The device utilizes at least one transmission element for transmitting a signal and at least two receiving elements for receiving a signal from the at least one transmission element and providing first and second output signals. The present invention also utilizes a receiving device for receiving the first and second output signals form the at least two receiving elements such that the difference or ratio of the two signals is utilized to determine the concentration. <IMAGE></p> |
