Abstract: A mass flowmeter of the thermal type, comprising a planar, thin substrate with a sensing surface that can be brought into direct or indirect contact with a flowing fluid during a measurement, wherein electrically controllable heating means and temperature sensor means for determining a temperature difference are provided on the sensing surface by a planar technique. The substrate with its sensing surface is present in particular in a cavity of a module into which a feed line and a drain line for the fluid issue.

Abstract: A mass flowmeter of the thermal type provided with a flow sensor with a flow tube through which a fluid can flow during operation, with a temperature sensor in an upstream position (A) and a heater (H) in a downstream position (B), and power control means and temperature measuring means for keeping the temperature difference between A and B at a predetermined constant value. Between A and B, the flowmeter is provided with means for preventing the temperature at A from rising owing to thermal conduction from B to A via the tube in the case of no flow or a weak flow.

Abstract: The invention relates to a flowmeter of the thermal type with a single flow sensor which is connected to control and temperature measuring means for measuring in a first measuring range by a first measuring method and in a second measuring range by a second measuring method. Detection means detect the measuring method to be selected on the basis of a flow measurement, and control means control the flow sensor in accordance with the selected measuring method.

Abstract: A thermopile on an electrically insulating substrate. A pattern is arranged on this substrate of parts which consist of a first conductive material, to which a second conductive material is applied, and parts which consist only of the first conductive material. The second material is better electrically conducting than the first and, connected as thermopile, can thereby generate a certain thermo-voltage. The second material is applied to the first, starting from a layer of the first material on the substrate, by etching stripes therein via the so-called “blind-hole etching” technique and applying the second material in these stripes.

Abstract: Mass flowmeter comprising a hollow conduit of a heat-conducting material for transporting in a determined flow direction a fluid with a mass flow rate to be measured, a first temperature-sensitive resistor element at a first position in thermal contact with this conduit for supplying heat to said fluid, a temperature sensor and measuring and control means connectable to the resistor element and the temperature sensor, wherein the temperature sensor is provided in thermal contact with the conduit at a second position upstream in relation to said first position, and the measuring and control means are adapted to maintain a constant difference in temperature at said first and second positions.

Abstract: Method for manufacturing a thermopile on an electrically insulating substrate. A pattern is arranged on this substrate of parts which consist of a first conductive material, to which a second conductive material is applied, and parts which consist only of the first conductive material.

Abstract: Method for manufacturing a thermopile on an electrically insulating substrate. A pattern is arranged on this substrate of parts which consist of a first conductive material, to which a second conductive material is applied, and parts which consist only of the first conductive material. The second material is better electrically conducting than the first and, connected as thermopile, can thereby generate a certain thermo-voltage. The second material is applied to the first, starting from a layer of the first material on the substrate, by etching stripes therein via the so-called “blind-hole etching” technique and applying the second material in these stripes.

Abstract: The invention relates to a device for measuring the flow of a medium e.g., a gaseous medium or a fluid medium, which device is based on measuring and affecting the temperature distribution of a medium flowing along, which flow sensor comprises two object, each comprising a heating element and a temperature sensor, the measured temperature difference being kept, by way of a control loop, to the value of zero, the asymmetry of the power supply to the objects in order to comply with the aforesaid criterion, according to which the temperature difference must be zero, being representative of the value to be measured of the medium flow, taking into account parameters associated with the medium, such as its density and specific heat.

Abstract: Mass flowmeter comprising a hollow conduit of a heat-conducting material for transporting in a determined flow direction a fluid with a mass flow rate to be measured, a first temperature-sensitive resistor element at a first position in thermal contact with this conduit for supplying heat to said fluid, a temperature sensor and measuring and control means connectable to the resistor element and the temperature sensor, wherein the temperature sensor is provided in thermal contact with the conduit at a second position upstream in relation to said first position, and the measuring and control means are adapted to maintain a constant difference in temperature at said first and second positions.

Abstract: Method for momentarily identifying the composition of a gas or fluid flow, and device for carrying out the method.The flow is conducted through an orifice in a conduit. Parallel to--and passing over--the orifice, there is a capillary conduit having a mass-flow meter therein. There is measured a combination of physical properties. By comparing said combination with values from a table, each of which is associated with a specific gas composition, the current composition may be determined.

Abstract: Method and device for measuring flows of fluids, such as liquids and gases, flowing through a tube (16). The tube is heat-conducting and is heated at a certain location (18), with the heat on the one hand moving by way of the tube wall (17) in a direction contrary to the fluid flow (15) and on the other hand flowing off into a heat-conducting body (20) which preferably extends substantially parallel to the tube. The temperature difference between the tube wall (17) and the conducting body (20) is measured, e.g., by a thermopile (19) and is a measure of the flow gone past. The device preferably includes a thermopile (19) for carrying out the measurement.