Stanislaw S. Stuchly

Microwave Surface Level Monitor

Nonconventional applications of a microwave multifrequency CW radar for contactless and continuous monitoring of liquid surface levels are discussed. Analytical and experimental analysis utilizing the multiple-frequency technique to eliminate ambiguous distance measurements are presented. The method makes use of a waveguide partially immersed in the liquid and allows the measurement of phase differences between the outgoing and reflected waves, which is then utilized to determine the liquid level. Potential applications of the proposed method are the monitoring of water levels in piezometers and other liquids in large storage tanks.

Microwave Doppler-Effect Flow Monitor

This paper contains a discussion of the capabilities and limitations of a modem solid-state microwave Doppler radar used for monitoring the flow rates of moving materials. Experimental results Of monitoring flow rates of paritculate solids are presented. It has been concluded that the average Doppler frequency is proportional to the average bulk velocity. When the bulk density and the crosssectional area of the pipe are known, the system-provides contactless means of-monitoring the mass flow rate of particulate solids.

A Microwave Open-Ended Cavity as a Void Fraction Monitor for Organic Coolants

A novel application of an open-ended microwave cavity in the field of on-line nuclear instrumentation, specifically to the determination of the void fraction in organic coolants used for cooling nuclear reactors, is presented. The sensor consists of a section of circular waveguide inserted in series with the piping system transporting the coolant. For the selected frequency of operation, the sensor section forms a resonant cavity whose resonant frequency, being a measure of the void fraction, can be automatically and continuously monitored by an electronic system.

Monitoring the Velocities of Particulates Using Doppler Radar

abstractThis paper contains the description of a novel technique for monitoring the velocities of particulate solids. The sensor consists of either a Doppler transceiver or a self-detecting Gunn-effect diode. Experimental results of gravitational flow of wheat, rapeseeds and sand have been presented.

A new electromagnetic current transformer for EHV power systems

A new current transformer aimed at monitoring for purpose of protection and control of EHV power systems and based on the application of a microwave YIG-tuned transistor oscillator as a sensor is suggested. The principle of operation, description of the experimental system, and experimental results of the laboratory and field tests are presented. It is found that the concept of remote monitoring of the EHV system by this electromagnetic current transformer is technically and economically fully feasible.

A Waveguide Applicator for Irradiation of Samples At Controlled Temperature

abstractA new waveguide applicator for irradiation & small samples of aqueous solutions with microwave energy under controlled temperature has been developed. The principle of operation, the electrical and thermal designs of the applicator as well as the experimental results for a WR284 waveguide applicator operating at a frequency of 2.45 GHz are presented.

Measurement of Current in EHV and UHV Transmission Lines using YIG-tuned Devices

New systems for current measurement in HV DC and HV AC transmission are described. The systems utilize the YIG-tuned devices placed in close vicinity of the HV line conductor as a magnetic field sensor. The output signal of the system is proportional to the resonant frequency of the YIG sphere in the YIG-tuned device. This resonant frequency is linearly dependent on the magnetic field created by current to be measured. The system consists of two basic parts, a high potential unit placed at the HV line conductor and a ground potential unit. These both parts are connected by microwave link which provides necessary isolation. The block diagrams of the systems and some of the investigation results are given.