Abstract: An electrolytic plating method, including: preparing a plating solution including water which is a primary medium, a sulfonic acid, and tin, copper, and silver ions, and a complexing agent, concentrations of the sulfonic acid, and tin, copper, and silver ions being 0.5 to 5 mol/L, 0.21 to 2 mol/L, 0.002 to 0.02 mol/L, and 0.01 to 0.1 mol/L, respectively, a mole ratio of the silver-ion concentration to the copper-ion concentration being in a range of 4.5 to 5.58; and separating a solution around a soluble anode containing 90 percent or more of tin from the plating solution on a cathode side by a non-ionic micro-porous membrane having a pore diameter of 0.01 to 0.05 ?m and a thickness of 5 to 100 ?m.

Abstract: A tin-silver-copper contains plating solution which comprises water which is a primary medium, a sulfonic acid, a tin ion, a copper ion and a silver ion, wherein concentrations of the silver ion, the tin ion and the copper ion are 0.0015 to 0.1 mol/L, 0.21 to 2 mol/L and 0.002 to 0.02 mol/L, respectively; a plating film which has 2.6 to 3.4 weight percent of silver, 0.4 to 0.7 weight percent of copper and the substantially balanced amount of tin; an electrolytic plating method for use in forming the above plating film from the above plating solution; and a soldering method using the plating film.

Abstract: A gasoline detecting device is provided with a suction nozzle arranged adjacent to an element to be inspected, a sensor for detecting gasoline within the sucked air arranged adjacent to the suction nozzle, and a body arranged in relation spaced from the suction nozzle. The body has a sensor drive unit for driving the sensor and for displaying the detection and a suction unit communicating with the suction nozzle. The gasoline detecting device can detect gasoline leakage from the element to be inspected.