The present invention relates to a solution metering apparatus, more particularly a metering apparatus for measuring the fluid level in a solution storage vessel.
Conventional fluid level measuring devices measure the fluid quantity. Fluid measuring devices are generally sizable and complex in structure, and hence more costly. However there is increasingly market demand for small-size and low-cost products. Take the example of fuel cell system, its applications in portable electronic devices are picking up. In a fuel cell system that uses hydrogen-rich fuel (e.g. methanol) and oxygen fuel to undergo electrochemical reaction and output power, it is necessary for users to know when to replenish the fuel when fluid concentration or level becomes low. Thus it is necessary to detect the fluid fuel level and volume in the fuel container. Such detection work is typically achieved through expensive metering sensor, which is rather uneconomical when used extensively in portable electrical products.
In light of the drawbacks of conventional fluid measuring devices, the inventor with many years of experience in the industry aims to develop an improved fluid measuring device that effectively achieves the objects.
The primary object of the invention is to provide a solution metering apparatus for measuring the fluid level or other physical characteristics of fluid in a solution storage vessel that also has a structure able to protect the circuitry of the metering apparatus.
Another object of the invention is to provide a solution metering apparatus that uses its sensing member to measure capacitance, inductance, impedance or any electric signal in the combination of such signals to obtain corresponding physical characteristics of the solution.
Yet another object of the invention is to provide a solution metering apparatus that can be used in a fuel cell system for measuring the fluid fuel level in the fuel storage vessel of the fuel cell.
A further object of the invention is to provide a solution metering apparatus used in measuring the solution level in a solution storage vessel and comprising a substrate; a sensor layer consisting of a first sensing member and a second sensing member where the first sensing member and the second sensing member respectively have, in horizontal direction, a plurality of sidewardly extended strip lines that are alternately arranged, and the sensor layer is disposed on one side surface of the substrate; a protective layer overlying the sensor layer to determine the height of the fluid in the vessel based on the physical characteristics of the fluid as detected by the sensor layer, particularly its capacitance characteristics, and then determine whether to feed more fluid into the vessel.
The objects, features and effects of the invention are described in detail below with embodiments in reference to the accompanying drawings.
The protective layer 30 envelops the entire substrate 10 and the outer surface of the sensor layer 20.
The plurality of sidewardly extended strip lines in the horizontal direction of the first sensing member 22 and the second sensing member 24 are not necessarily parallel strip lines, so long as they produce capacitance effect.
The material for the substrate 10 and the protective layer 30 may be glass fiber (FR4, FR5), epoxy resin, glass fiber laminate, ceramic laminate, polymer laminate or their mixtures thereof to give the substrate 10 and the protective layer 30 corrosion resistance so as to protect the metal material in the sensor layer 20 from corrosive fluid. In addition, the aforementioned materials are materials commonly used in the industry and their processes are mature for easy manufacture of the substrate 10 and the protective layer 30.
The material for the protective layer 30 of solution metering apparatus 1 used in the fuel storage vessel takes into account in avoid of possible corrosion of the lead wire of electric circuit by the fuel. Thus the material for the protective layer 30 can be selected further from Teflon, polyethylene and non-polar material, in which Teflon can be coated onto the outer surface of protective layer 30 and substrate 10 by way of surface coating. The entire outer surface of the solution metering apparatus can also be coated with Teflon.
As such, the solution metering apparatus provided by the invention can accurately measure the quantity of solution in a solution storage vessel, including the quantity of the fuel solution in the fuel storage vessel of a fuel cell. The invention possesses inventive step and meets the essential criteria for patent.
The preferred embodiments of the present invention have been disclosed in the examples. However the examples should not be construed as a limitation on the actual applicable scope of the invention, and as such, all modifications and alterations without departing from the spirits of the invention and appended claims shall remain within the protected scope and claims of the invention.
Number | Date | Country | Kind |
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095221901 | Dec 2006 | TW | national |