Abstract: A variable mode microwave water cut monitor includes a test cell which contains a fluid sample. Apparatus controls the provision and removal of the fluid sample to effect different modes of operation for the monitor, a normal test mode and at least two calibration modes. A source provides microwave energy to one of a first antenna which in turn provides the fluid sample in the test cell with microwave energy. A second antenna receives the microwave energy that has passed through the fluid sample. A detector detects the received microwave energy and provides a signal corresponding thereto. An indicator provides an indication of the water cut of the fluid sample in accordance with the received signal power, a phase difference between the source provided microwave energy and the received microwave energy and internally recorded calibration data for water alone and oil alone.

Abstract: A petroleum stream microwave water cut monitor includes test cell means which contains a reference petroleum multiphase fluid sample and which has a sample stream of a petroleum stream passing through it. The test cell is maintained at a predetermined temperature. A source provides microwave energy to one of a first pair of antennae which provides the petroleum stream flowing in the test cell or the reference sample in the test cell with microwave energy. One of a second pair of antennae receives the microwave energy that has passed through either the petroleum stream or the reference sample. A detector detects the received microwave energy and provides a signal corresponding thereto. An indicator provides an indication of the water cut of the petroleum stream in accordance with the received signal power and a phase difference between the source provided microwave energy and the received microwave energy.