稳态法测导热系数

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1、五、数据处理1、在内容三所测数据中，选取稳态温度附近10组数据，用逐差法计算散热盘C在稳态T2附近的冷却速率Vc。根据选取稳态温度附近10组数据44.744.344.143.342.642.241.641.240.840.5由逐差法计算有Vc={(44.7-42.2)+(44.3-41.6)+(44.1-41.2)+(43.3-40.8)+(42.6-40.5)}/(5*2.5)=1.048℃/min=0.0175℃/s2、计算出待测样品B的导热系数λ:λ=｛mchB（Rc+2hc）/2πRb²(

2、T1-T2)(Rc+hc)｝*(△T/△t)m=0.669kgc=385J/kg*K样品盘B直径/cm9.9669.9509.9489.9589.956厚度/cm0.8340.8320.8320.8360.832铜盘C直径/cm9.9609.9589.9809.9569.942厚度/cm0.9840.9860.9820.9860.982hB=(0.834+0.832+0.832+0.836+0.832)/5=0.8332cm=8.332*10^-3mRc=(9.960+9.958+9.980+9.

3、956+9.942)/(2*5)=4.9796cm=4.9796*10^-2mhc=(0.984+0.986+0.982+0.986+0.982)/5=0.984cm=9.84*10^-3mRb=(9.966+9.950+9.948+9.958+9.956)/(2*5)=4.9778cm=4.9778*10^-2mT1=53.1℃T2=42.3℃△T/△t=Vc=0.0175℃/sλ={0.669*385*8.332*10^-3*(4.9796*10^-2+2*9.84*10^-3)/2*3.14

4、*(4.9778*10^-2)²*(53.1-42.3)(4.9796*10^-2+9.84*10^-3)}*0.0175=0.261W/m*K3、求出环氧盘λ的不确定度，给出结果表达式。（只考虑冷却速率误差）由于比较复杂，过程见实验报告纸。可得结果为Uλ=0.036W/m*K∴λ=0.261±0.036W/m*K4、分析误差原因。测量盘的直径与厚度时由于是人为读数，有读数误差，再有环境误差，盘的质量可能由于多次实验有磨损存在误差等等。5、所有测量数据都要列表。(1)、样品盘B直径/cm9.966

5、9.9509.9489.9589.956厚度/cm0.8340.8320.8320.8360.832铜盘C直径/cm9.9609.9589.9809.9569.942厚度/cm0.9840.9860.9820.9860.982(2)、t/minT2/℃012.4213.1414.3616.5819.21022.11224.61426.91629.01830.82032.32233.52434.72635.82836.63037.33238.03438.63639.13839.54039.94240

6、.24440.64640.94840.95041.25241.35441.55641.75841.76041.96242.06442.06642.26842.37042.37242.37442.37642.37842.3(3)、t/sT2/℃047.33046.96046.39045.812045.415044.918044.721044.324044.127043.330042.633042.236041.639041.242040.845040.548039.951039.554039.257

7、038.860038.463038.0