【正文】 ng with the warm waste change the current carrier number along with the temperature change, the temperature increment, the current carrier number increases, electric conduction ability enhancement. Thus electronic resistivity F falls. Regarding transition metal oxide pound semiconductor, for example Ni O, because its acceptor ionizing energy is very small, broad basic ionized pletely in the room temperature, namely the current carrier density basically has nothing to do with the temperature, this time, should mainly consider the transport ratio and the temperature relations .By the semiconductor physics knowledge, the transport ratio expresses by the equation below: In the formula: The d oxygen octahedron gap is away from (Ni O is the Na Cl structure)。 e is the electronic electric quantity .ε0 is the vacuum coefficient of d i electrical loss. When the electronic overstepping potential barrier enters 248。0 is the barrier height .According to the equation, the barrier height 248。 m) the interior is the semiconductor nature。 m, therefore is the insulator. If carries on the doping in BaTio3, may cause the BaTio3 semiconductor, for example: Mixes by %% rareearth element, but causes it to bee has under the normal temperature10Ω Its resistance number the which reduces along with the temperature t ascension is called negative temperature (NTC)。無 錫 職 業(yè) 技 術(shù) 學(xué) 院 畢業(yè)設(shè)計說明書（英文翻譯） 2 英文翻譯 Temperature humidity sensor The sensor in type many sensors, the temperature sensor and applies two aspects in its output both is second to and with it correlation temperature is an important physical parameter, he affects all physical, chemistry and biomedicine process march, regardless of in the industry, the agriculture, the scientific research, the national defense and people39。s daily life each aspect, the temperature survey and the control all is the extremely important with the electronic technology and the materials science development, to each kind of new thermal element and the temperature sensor request structure advanced, the performance is stable, satisfies the more and more high request which proposed to the temperature survey and the control. Sensor classification carries on classified resistance type PN according to the manufacture temperature sensor material and the principle of work to tie the type thermoelectricity type radiation formula r operating region is refers to the resistance value to have the remarkable change temperature sensor along with the temperature change, it may transform directly the temperature as the electrical the operating temperature scope, its resistance the which increases along with the temperature ascension is called positive temperature coefficient (PTC)。 The negative temperature which reduces suddenly along with the temperature rise is called critical (CTR) in a warm area internal resistance. 1. PTC principle of the PTC r usually to use the (BaTio3) ceramic material, the pure BaTio3 ceramics have the extremely high electronic resistivity under often the temperature, above 108Ω m N line of semiconductors .Has electricity semiconductor BaTio3, when the temperature achieved when Curie temperature T, it transforms by the tetragonal system into the cubic system, this time its electronic resistivity leap increases several magnitudes (103107 times).Positive temperature coefficient the (PTC) acts according to this nature manufacture. After in semiconductor multicrystal grain structure BaTio3, its crystal grain (general size small is approximately 310 181。 But the crystal boundary (has f e r r o electricity) for the highresistance area. When type crystal external voltage, voltage majority of landings on highresistance crystal boundary level, thus the crystal boundary has an effect to the material electric conductivity .The electron must pass through the crystal boundary barrier potential barrier from a crystal grain to be able to arrive another crystal grain .Below Curie temperature T c, BaTio3 is tetragonal system dielectric, the existence has the spontaneous polarized very strong internal electric