Abstract: One or a plurality of branch paths (3) having opening end portions (2) formed in the vicinity of an inner wall surface of a main path (1) through which a fluid flows so as to point the upstream or downstream side of the main path, and causing part of the fluid running in the vicinity of the inner wall surface of the main path to flow therethrough via the opening end portions, to thereby detect flow rates of the fluids running through the branch paths by using a thermal flow sensor (4). Preferably, a plurality of opening end portions (2a) pointed toward the upstream side or a plurality of opening end portions (2b) pointed toward the downstream side are arranged at regular intervals along the path cross section of the main path around the axis of the main path, to thereby measure a fluid flow with high accuracy.

Abstract: One or a plurality of branch paths (3) having opening end portions (2) formed in the vicinity of an inner wall surface of a main path (1) through which a fluid flows so as to point the upstream or downstream side of the main path, and causing part of the fluid running in the vicinity of the inner wall surface of the main path to flow therethrough via the opening end portions, to thereby detect flow rates of the fluids running through the branch paths by using a thermal flow sensor (4). Preferably, a plurality of opening end portions (2a) pointed toward the upstream side or a plurality of opening end portions (2b) pointed toward the downstream side are arranged at regular intervals along the path cross section of the main path around the axis of the main path, to thereby measure a fluid flow with high accuracy.

Abstract: A seedling planter mounted on a trailer is provided with means to sense the side walls of ridges of earth and a means to position the planter over ridges of earth in response to the ridge side wall sensing means by transporting the planter sideways from the for/aft center line of the trailer irrespective of the track of the trailer.

Abstract: In a method for making a joined pipe, a main pipe is cut so that two V-shaped edges of a right angle are formed in the diametrical positions on the periphery of the main pipe, and a branch pipe is cut so that two peaked edges of a right angle are formed in the diametrical positions on the periphery of the branch pipe. Then, the facets of the V-shaped edges and the peaked edges are fused by heating, and butt-welded under pressure.

Abstract: A combustion control device capable of detecting a self-discharge state caused by a failure of an ultraviolet ray detecting tube by interrupting flames from a combustion mechanism to an ultraviolet ray detecting tube by opening and closing a shutter, integrating, by an integrating circuit, detection signals from this ultraviolet ray detecting tube only when the shutter is closed, comparing the result of this integration with a preset judgement level by use of a first judgement circuit, and determining a failure by comparing a result of this comparison with a preset failure judgement frequency by use of a second judgement circuit, thereby improving maintainability.

Abstract: A flame detecting thermocouple for use with a gas valve to insure that the pilot flame exists before the gas valve can turn on the main burner. The thermocouple has a first rod shaped element which is composed of a high potential side thermoelectric material such as Chromel, Inconel, iron-chromium alloy and a second rod shaped element composed of a low potential side thermoelectric material formed of a 0.7 to 2% yttrium, 45-70% copper and the remainder of the alloy is nickel, and the elements are welded together at their ends to provide a junction which can be heated by a flame to produce a thermoelectric output at the other ends of the element.