US 4,144,741 A · Void detecting device

Abstract

A detector to be inserted into a flowing conductive fluid, e.g. sodium coolant in a nuclear reactor, comprising at least one exciting coil to receive an a-c signal applied thereto and two detecting coils located in the proximity of the exciting coil. The difference and/or the sum of the output signals of the detecting coils is computed to produce a flow velocity signal and/or a temperature-responsive signal for the fluid. Such flow velocity signal or temperature signal is rectified synchronously by a signal the phase of which is shifted substantially .+-. 90.degree. with respect to the flow velocity signal or temperature signal, thereby enabling the device to detect voids in the flowing fluid without adverse effects from flow velocity variations or flow disturbances occurring in the fluid.

Claims4

Dependent claims

A void detecting device comprising a detector having at least one exciting coil to receive an a-c signal applied thereto and two detecting coils provided in the proximity of said exciting coil, said detector being adapted to be inserted into a conductive fluid to be measured;

and a circuit for obtaining a flow-or-temperature-responsive output signal by combining signals of said two detecting coils;
the improvement wherein a void signal is obtained comprising:
synchronized rectification means having first and second inputs and a void signal output;
means coupling said flow-or-temperature-responsive output signal to said first input;
and
means coupling to said second input a signal the phase of which is shifted substantially .+-. 90.degree. with respect to said flow-or-temperature-responsive output signal.

3 more elements

Dependencies are inferred from the claim text.

Void detecting device

Life of this patent

Void detecting device

Life of this patent

Abstract

Claims4