Clamp-on thermal meter for non-intrusive flow measurement in a conduit

A non-intrusive thermal flow measurement device for quantitatively determining fluid flow in a conduit, comprising:

• a flexible clamp structure configured to externally conform to and maintain continuous circumferential thermal contact with conduits of varying diameters without requiring interchangeable inserts, the flexible clamp structure comprises two half-shells configured to flexibly adapt and snugly conform to conduit diameters between a range between approximately ¼ inch to approximately ⅝ inch, wherein the flexible clamp structure includes an upper arm having a grip end and a distal end with a concave lower surface, and a lower arm having a grip end and a distal end with a concave upper surface, and a spring loaded member for allowing the upper arm to pivot relative to the lower arm, wherein the concave lower surface on the distal end of the upper arm and the concave upper surface on the distal end of the lower arm grip about conduit wall;
• at least one heater configured to provide a heat flux of approximately 10 Watts per square inch to approximately 20 Watts per square inch, the heater configured to externally heat only a portion of the conduit wall at a measurement location, without directly heating the bulk fluid inside the conduit wall, thereby avoiding vaporization and enabling portable, battery-powered operation;
• a plurality of temperature sensors positioned along the conduit wall and configured to measure temperature differentials at distinct points along the conduit wall, the plurality of temperature sensors includes at least one sensor positioned upstream of the heater, at least one sensor positioned directly on the heater, and at least one sensor positioned downstream of the heater, wherein spacing between adjacent sensors is approximately 1.5 inches or 38 millimeters;
• wherein an upper half-shell of the two half-shells, includes:
• an upper flexible pad pliable support between the upper half-shell and an upper half heater temperature sensor, and an upper half heater pad between the upper half heater temperature sensor and an upper half heater element, and
• wherein a lower half-shell of the two half shells includes;
• a lower flexible pad pliable support between the lower half-shell and lower half-heater temperature sensor, and a lower half heater pad between the lower half heater temperature sensor and a lower half heater element:
• and
• an electronic processor configured to calculate and determine a fluid flow rate in the conduit based on steady-state temperature differentials which are the temperature differentials measured by said sensors when the temperature differentials have reached a steady state within a time frame of approximately 3 minutes to approximately 15 minutes, wherein overall weight of the device is up to approximately 1 pound or approximately 454 grams, overall width of the device is approximately 1.7 inches or approximately 43 millimeters, and overall length of the device is approximately 7.6 inches or approximately 193 millimeters.

A non-intrusive thermal flow measurement device for quantitatively determining fluid flow in a conduit, comprising:

• a flexible clamp structure configured to externally conform to and maintain continuous circumferential thermal contact with conduits of varying diameters without requiring interchangeable inserts, the flexible clamp structure comprises two half-shells configured to flexibly adapt and snugly conform to conduit diameters between a range between approximately ¼ inch to approximately ⅝ inch, wherein the flexible clamp structure includes a fixed mechanical clamp assembly with an upper shell having a lower facing concave surface, and a lower shell having an upper facing concave surface, wherein the upper shell and the lower shell wrap about a section of the conduit wall, the fixed clamp assembly is assembled by either fasteners selected from at least one of screws and bolts for locking the upper shell to the lower shell, or is assembled by securing members selected from at least one of:
• magnets, latches, ties, spring clips, and latch clamps for securing the upper shell to the lower shell;
• at least one heater configured to provide a heat flux of approximately 10 Watts per square inch to approximately 20 Watts per square inch, the at least one heater configured to externally heat only a portion of a conduit wall at a measurement location, without directly heating the bulk fluid inside the conduit, thereby avoiding vaporization and enabling portable, battery-powered operation;
• a plurality of temperature sensors positioned along the conduit wall and configured to measure temperature differential between distinct points, the plurality of temperature sensors includes at least one sensor positioned upstream of the heater, at least one sensor positioned directly on the heater, and at least one sensor positioned downstream of the heater, wherein spacing between adjacent sensors is approximately 1.5 inches or approximately 38 millimeters;
• wherein an upper half-shell of the two half-shells, includes:
• an upper flexible pad pliable support between the upper half-shell and an upper half heater temperature sensor, and an upper half heater pad between the upper half heater temperature sensor and an upper half heater element;
• wherein a lower half-shell of the two half shells includes:
• a lower flexible pad pliable support between the lower half-shell and lower half-heater temperature sensor, and a lower half heater pad between the lower half heater temperature sensor and a lower half heater element;
• and
• an electronic processor configured to calculate and determine a flow rate in the conduit based on steady-state temperature differentials which are the temperature differentials measured by said sensors when the temperature differentials have reached a steady-state within a time frame of approximately 3 minutes to approximately 15 minutes, wherein overall weight of the device is up to approximately 1 pound or approximately 454 grams, overall width of the device is approximately 1.7 inches or approximately 43 millimeters, and overall length of the device is approximately 7.6 inches or approximately 193 millimeters.