The Study And Development Of Formaldehyde Inspection Instrument On The Basis Of Sensible Electrod Pole

Formaldehyde is a kind of bioplasm poison, it is very dangerous for people. We have attached importance to its safety in environment for us, so it is so important to inspect it. There are two kinds of national standard methods to analyze formaldehyde, spectrophotometry and gas chromatography. What is characteristic of the two methods is that they both require collecting gas specimen first then analyzing them at laboratory. The disadvantages include that the analytic period is long, the cost is high, the manipulative process is intricate, and the results can not reflect the situation of indoor formaldehyde pollution real time. However there has been a small amount of formaldehyde protable test instrument, they are expensive. In view of this, development of a new rapid continuous automatic, cheap monitor has become a very meaningful work. The content of this thesis mainly includes:(1)First, compare and analise the former various methods of formaldehyde checking, based on it, The detection method for this dissertation is also presented.(2)The working principle of formaldehyde sensor was presented. Then design a new formaldehyde checking system which is small, easily handle, expediently portuble, fast checking, fieldworking and inexpensive.(3)Design the hardware of formaldehyde checking system. The formaldehyde gas passes the hydrophobe-film and redoxes in the electrode, then produces to a slight ecuctrnic signal and turn out to be outrun signal after passes through the amplifier. At the same time, the circuit keep the invariable valtage between the working electrode and thereferenced electrode. The voltage signal will be shown on the instrument panel in number after the integrate cirant. (4)Finish the software design and program. The formaldehyde checking system function will be completed coordinately by the hardware and software. For the hardware , it finishes the collection and transference of all kinds of sensor signals and display them, the software finished the operation and controlling of signals.(5)A model machine has been made according to the design, and experiments have been done. The experiment validates the correctness of the design.