Non-contact type measuring apparatus for conductivity and permittivity of non-conductive fluid using RF signal

A non-contact type measuring apparatus for conductivity and a variation in permittivity characteristic of a non-conductor using a radio frequency (RF) signal, the non-contact type measuring apparatus comprising:

• a non-conductive tube configured to allow a fluid to flow;
• first and second coil antennas configured to be fitted and installed at the non-conductive tube, wherein the second coil antenna is spaced downstream at a predetermined interval W apart from the first coil antenna;
• and
• a controller configured to measure and control conductivity and a variation in characteristic of a non-conductor by analyzing a frequency and a signal intensity of an RF signal,
• wherein the controller transmits RF signals having various frequencies to a medium in the non-conductive tube through a magnetic field induced by the first coil antenna to generate an induced current, controls the second coil antenna to receive an induced current signal having the various frequencies transmitted through the medium, and detects conductivity of a fluid and a variation in characteristic (permittivity) of a non-conductor by comparing a difference in intensity between the RF signals transmitted from the first coil antenna and the RF signals received from the second coil antenna with a difference in intensity of an RF signal varied according to a state of the medium on the basis of the frequency and the signal intensity of the transmitted RF signals, which are stored in advance in the controller.