Abstract: A thermal dispersion switch/transmitter for determining flow rate and liquid level in a non-contacting apparatus. A special preparation of one or more small spots in the outside surface of the wall of the conduit, standpipe or container enables one or more thermally sensitive elements to reside very close to the fluid on the opposite side of the wall. A temperature sensor is formed of a raster pattern electrical conductor deposited on a thin, electrically insulative, thermally conductive flat chip. One temperature sensor is time-shared and is periodically self heated and functions as the reference as well as the active or heated sensor of the invention. One alternative is to employ two temperature sensors, one being a reference sensor and the other being the active sensor. An alternative embodiment employs the same construction of one or more small, very thin membrane surfaces to which multiple detectors are mounted inside a probe inserted into the conduit.

Abstract: A liquid/gas phase detector system employing a sensor to detect fluid phase, flow rate, and temperature. A flow conditioner in the form of a pipe segment with an inverted V-shaped section forming a weir is adapted for coupling in a horizontal conduit downstream from a source of liquid flow. When a thermal dispersion technology sensor is used, heated and non-heated temperature sensitive elements extend within the pipe segment on the upstream side of the weir. Fluid flow changes encountering the sensing elements cause temperature changes which produce an output signal relating to fluid phase (gas or liquid) and flow rate. Several different embodiments for the flow conditioner are provided.

Abstract: A thermal dispersion switch/transmitter for determining flow rate and liquid level in a non-contacting apparatus. A special preparation of one or more small spots in the outside surface of the wall of the conduit, standpipe or container enables one or more thermally sensitive elements to reside very close to the fluid on the opposite side of the wall. A temperature sensor is formed of a raster pattern electrical conductor deposited on a thin, electrically insulative, thermally conductive flat chip. One temperature sensor is time-shared and is periodically self heated and functions as the reference as well as the active or heated sensor of the invention. One alternative is to employ two temperature sensors, one being a reference sensor and the other being the active sensor. An alternative embodiment employs the same construction of one or more small, very thin membrane surfaces to which multiple detectors are mounted inside a probe inserted into the conduit.

Abstract: A flow meter having reference and active thermal sensing elements and a pressure transducer configured to be placed in a conduit of flowing fluid. Appropriate computation apparatus is employed to modify the flow velocity reading resulting from normal comparison of the thermal sensors in accordance with pressure differences reflected by the pressure transducer.

Abstract: An insertion mass flow sensor having coaxial, spaced reference and active sensors mounted within an opening adjacent the distal end of the elongated flow element. The distal end of the flow element is adapted to be positioned at the center of the conduit through which fluid is flowing. In the preferred embodiment, a turbulence inducing element is mounted across the opening to condition the fluid that encounters the active sensor.

Abstract: A safety device for heated sensors. A signal representing a threshold voltage is compared with a signal from the sensor representing sensor temperature. If the latter is greater than the threshold signal, a switch is opened to remove power from the means for heating the sensor. The normal state of the switch is closed, so after cooling, heat is again applied to the sensor.