自由场法测量声功率.doc

实验四 自由场法测量声功率一、 实验目的掌握半消声室精密法测声功率的原理和方法。二、 实验要求1. 在消声室采用半球面作为测量表面。2. 每个测点测量1次。三、 实验环境1半消声室2噪声源（以320W大宇6060T手电钻为例）3HS6288B声级计（2型）412吋传声器延长电缆5传声器支架四、 实验内容、步骤1. 实验内容：测量电钻空载时的声功率2. 实验原理：噪声源的辐射特性通常用指向特性和辐射功率描述。声功率的单位为瓦，如用声功率级表示，则式中为声源辐射功率，为声功率级（dB）；基准声功率为1012 W。3. 指向性声源的声功率测量将声源放在自由场中，测量出声源周围固定距离处假想球面上许多点的声压级，球的半径应该使测量点位于远场。测量点数目不能太少，测得数值之间的最大变化不得超过6 dB左右，否则必须在更多的点上进行测量。确定声源的声功率时，将假想球面分成与测点数目相同的面积，传声器测点占有的测试半球的面积相等，用下式求出表面平均声压级：式中是表面平均声压级；是第i个测点的声压级，N是测点数目。 这时自由场中噪声的声功率为： 式中是测试球面上表面平均声压级,。下面给出以声源为原点测点的直角坐标（x,y,z），z轴选择垂直于水平面向上的方向。表4.1 测点直角坐标分布如下:测点号x/ry/rz/r12345678910-0.990.500.500.450.450.890.330.660.3300-0.860.860.770.7700.570-0.5700.150.150.150.450.450.450.750.750.7504. 实验步骤图4.1 半球面测点布置示意图将HS自由场传声器装加在HS6288B声级计的延长电缆上并进行校准，在消声室地面中央处画圆确定测量表面的位置，将电钻置于圆心，将传声器夹在支架上，调整支架延伸杆的长度及角度，按图1确定测点位置依次测量各点声压级，按上式计算被测电钻的声功率级。五、 实验结果1. 每个测点的原始记录数据：半球半径 r=0.8m测点1的记录数据序号频率（Hz）声压级（dB）16.3000000000e+0014.26850e+00128.0000000000e+0013.91176e+00131.0000000000e+0024.49067e+00141.2500000000e+0024.87235e+00151.6000000000e+0025.65264e+00162.0000000000e+0026.03713e+00172.5000000000e+0025.54823e+00183.1500000000e+0026.13301e+00194.0000000000e+0026.27448e+001105.0000000000e+0025.83394e+001116.3000000000e+0025.23349e+001128.0000000000e+0025.74655e+001131.0000000000e+0036.23429e+001141.2500000000e+0035.09674e+001151.6000000000e+0035.11164e+001162.0000000000e+0035.50970e+001172.5000000000e+0035.07698e+001183.1500000000e+0034.81345e+001194.0000000000e+0035.05024e+001205.0000000000e+0034.33621e+001216.3000000000e+0033.89355e+001228.0000000000e+0033.92586e+001231.0000000000e+0043.95506e+001241.2500000000e+0043.59386e+001测点2的记录数据序号频率（Hz）声压级（dB）16.3000000000e+0012.85848e+00128.0000000000e+0013.07662e+00131.0000000000e+0023.49995e+00141.2500000000e+0023.67705e+00151.6000000000e+0024.44302e+00162.0000000000e+0024.86575e+00172.5000000000e+0024.85217e+00183.1500000000e+0026.02939e+00194.0000000000e+0025.87627e+001105.0000000000e+0026.10334e+001116.3000000000e+0026.16746e+001128.0000000000e+0025.91776e+001131.0000000000e+0036.38973e+001141.2500000000e+0036.22307e+001151.6000000000e+0036.61915e+001162.0000000000e+0036.68039e+001172.5000000000e+0037.65683e+001183.1500000000e+0037.62447e+001194.0000000000e+0037.22631e+001205.0000000000e+0036.83699e+001216.3000000000e+0036.55720e+001228.0000000000e+0036.60565e+001231.0000000000e+0046.48718e+001241.2500000000e+0046.30553e+001测点3的记录数据序号频率（Hz）声压级（dB）16.3000000000e+0012.86541e+00128.0000000000e+0013.17247e+00131.0000000000e+0024.22254e+00141.2500000000e+0023.91409e+00151.6000000000e+0024.55951e+00162.0000000000e+0024.82254e+00172.5000000000e+0024.99764e+00183.1500000000e+0025.81686e+00194.0000000000e+0025.70080e+001105.0000000000e+0025.97292e+001116.3000000000e+0026.09798e+001128.0000000000e+0026.41925e+001131.0000000000e+0036.98105e+001141.2500000000e+0037.22627e+001151.6000000000e+0037.24525e+001162.0000000000e+0036.95435e+001172.5000000000e+0037.46119e+001183.1500000000e+0036.90675e+001194.0000000000e+0037.62461e+001205.0000000000e+0037.48683e+001216.3000000000e+0036.74903e+001228.0000000000e+0036.70415e+001231.0000000000e+0046.67820e+001241.2500000000e+0046.49849e+001测点4的记录数据序号频率（Hz）声压级（dB）16.3000000000e+0012.41419e+00128.0000000000e+0012.85947e+00131.0000000000e+0024.05011e+00141.2500000000e+0023.30512e+00151.6000000000e+0023.69295e+00162.0000000000e+0024.30127e+00172.5000000000e+0024.66979e+00183.1500000000e+0025.76067e+00194.0000000000e+0025.59737e+001105.0000000000e+0026.05978e+001116.3000000000e+0026.31712e+001128.0000000000e+0026.71766e+001131.0000000000e+0037.04580e+001141.2500000000e+0037.16968e+001151.6000000000e+0036.91766e+001162.0000000000e+0037.38660e+001172.5000000000e+0037.05139e+001183.1500000000e+0037.12660e+001194.0000000000e+0037.52949e+001205.0000000000e+0036.99514e+001216.3000000000e+0036.90324e+001228.0000000000e+0036.77035e+001231.0000000000e+0046.56655e+001241.2500000000e+0046.44730e+001测点5的记录数据序号频率（Hz）声压级（dB）16.3000000000e+0012.45747e+00128.0000000000e+0012.62489e+00131.0000000000e+0023.17236e+00141.2500000000e+0023.83195e+00151.6000000000e+0024.47805e+00162.0000000000e+0024.71485e+00172.5000000000e+0024.87424e+00183.1500000000e+0025.98320e+00194.0000000000e+0025.77249e+001105.0000000000e+0026.00334e+001116.3000000000e+0026.22407e+001128.0000000000e+0026.54265e+001131.0000000000e+0036.85357e+001141.2500000000e+0036.80967e+001151.6000000000e+0036.94998e+001162.0000000000e+0036.59071e+001172.5000000000e+0037.19332e+001183.1500000000e+0037.28463e+001194.0000000000e+0037.15122e+001205.0000000000e+0037.04118e+001216.3000000000e+0036.61315e+001228.0000000000e+0036.50594e+001231.0000000000e+0046.70321e+001241.2500000000e+0046.18396e+001测点6的记录数据序号频率（Hz）声压级（dB）16.3000000000e+0012.80322e+00128.0000000000e+0013.08437e+00131.0000000000e+0023.63733e+00141.2500000000e+0023.58923e+00151.6000000000e+0024.20785e+00162.0000000000e+0024.03788e+00172.5000000000e+0024.42155e+00183.1500000000e+0024.93321e+00194.0000000000e+0025.31587e+001105.0000000000e+0025.65769e+001116.3000000000e+0025.98299e+001128.0000000000e+0026.58934e+001131.0000000000e+0037.10451e+001141.2500000000e+0037.03120e+001151.6000000000e+0036.86253e+001162.0000000000e+0037.08321e+001172.5000000000e+0036.92552e+001183.1500000000e+0036.84775e+001194.0000000000e+0037.39125e+001205.0000000000e+0037.00372e+001216.3000000000e+0036.67916e+001228.0000000000e+0036.54144e+001231.0000000000e+0046.61451e+001241.2500000000e+0046.39371e+001测点7的记录数据序号频率（Hz）声压级（dB）16.3000000000e+0015.87263e+00128.0000000000e+0015.72207e+00131.0000000000e+0025.17067e+00141.2500000000e+0024.85478e+00151.6000000000e+0024.67473e+00162.0000000000e+0024.57892e+00172.5000000000e+0024.72410e+00183.1500000000e+0025.55667e+00194.0000000000e+0025.69116e+001105.0000000000e+0025.87219e+001116.3000000000e+0026.28192e+001128.0000000000e+0026.96265e+001131.0000000000e+0037.27475e+001141.2500000000e+0037.01544e+001151.6000000000e+0036.93641e+001162.0000000000e+0037.13205e+001172.5000000000e+0037.50484e+001183.1500000000e+0037.33248e+001194.0000000000e+0037.40256e+001205.0000000000e+0036.90320e+001216.3000000000e+0036.61139e+001228.0000000000e+0036.72157e+001231.0000000000e+0046.51052e+001241.2500000000e+0046.15588e+001测点8的记录数据序号频率（Hz）声压级（dB）16.3000000000e+0012.79751e+00128.0000000000e+0012.91717e+00131.0000000000e+0023.74784e+00141.2500000000e+0023.70162e+00151.6000000000e+0024.25198e+00162.0000000000e+0024.26275e+00172.5000000000e+0024.58913e+00183.1500000000e+0025.66895e+00194.0000000000e+0025.57578e+001105.0000000000e+0025.86699e+001116.3000000000e+0026.35316e+001128.0000000000e+0027.03141e+001131.0000000000e+0037.40493e+001141.2500000000e+0036.95273e+001151.6000000000e+0036.67842e+001162.0000000000e+0037.21716e+001172.5000000000e+0037.64255e+001183.1500000000e+0037.49823e+001194.0000000000e+0037.39499e+001205.0000000000e+0037.01009e+001216.3000000000e+0037.08282e+001228.0000000000e+0036.72810e+001231.0000000000e+0046.49728e+001241.2500000000e+0046.54819e+001测点9的记录数据序号频率（Hz）声压级（dB）16.3000000000e+0012.66892e+00128.0000000000e+0012.83850e+00131.0000000000e+0023.63599e+00141.2500000000e+0023.64220e+00151.6000000000e+0024.21315e+00162.0000000000e+0024.34957e+00172.5000000000e+0024.57244e+00183.1500000000e+0024.96399e+00194.0000000000e+0025.32388e+001105.0000000000e+0025.77944e+001116.3000000000e+0026.40408e+001128.0000000000e+0026.64229e+001131.0000000000e+0037.01934e+001141.2500000000e+0036.94370e+001151.6000000000e+0036.63248e+001162.0000000000e+0037.21457e+001172.5000000000e+0037.47658e+001183.1500000000e+0037.42276e+001194.0000000000e+0037.61133e+001205.0000000000e+0037.03365e+001216.3000000000e+0036.65539e+001228.0000000000e+0036.75153e+001231.0000000000e+0046.48808e+001241.2500000000e+0046.45882e+001测点10的记录数据序号频率（Hz）声压级（dB）16.3000000000e+0012.79003e+00128.0000000000e+0012.71257e+00131.0000000000e+0023.56100e+00141.2500000000e+0023.31189e+00151.6000000000e+0023.83103e+00162.0000000000e+0024.24349e+00172.5000000000e+0024.67852e+00183.1500000000e+0025.70304e+00194.0000000000e+0025.96226e+001105.0000000000e+0026.35944e+001116.3000000000e+0026.63078e+001128.0000000000e+0026.95178e+001131.0000000000e+0036.95546e+001141.2500000000e+0036.91461e+001151.6000000000e+0036.87565e+001162.0000000000e+0037.12519e+001172.5000000000e+0037.27371e+001183.1500000000e+0036.92435e+001194.0000000000e+0037.12147e+001205.0000000000e+0036.92732e+001216.3000000000e+0036.57371e+001228.0000000000e+0036.60844e+001231.0000000000e+0046.33321e+001241.2500000000e+0046.19473e+001测点11的记录数据序号频率（Hz）声压级（dB）16.3000000000e+0015.98484e+00128.0000000000e+0015.85147e+00131.0000000000e+0025.84183e+00141.2500000000e+0025.78698e+00151.6000000000e+0025.81615e+00162.0000000000e+0025.90101e+00172.5000000000e+0025.96175e+00183.1500000000e+0026.28416e+00194.0000000000e+0026.25115e+001105.0000000000e+0026.21682e+001116.3000000000e+0026.85665e+001128.0000000000e+0027.22069e+001131.0000000000e+0037.08437e+001141.2500000000e+0037.12458e+001151.6000000000e+0037.19315e+001162.0000000000e+0036.81861e+001172.5000000000e+0036.89476e+001183.1500000000e+0036.91600e+001194.0000000000e+0037.85703e+001205.0000000000e+0037.22423e+001216.3000000000e+0037.12917e+001228.0000000000e+0036.69062e+001231.0000000000e+0046.57065e+001241.2500000000e+0046.40216e+001测点12的记录数据序号频率（Hz）声压级（dB）16.3000000000e+0014.15306e+00128.0000000000e+0013.72496e+00131.0000000000e+0023.76830e+00141.2500000000e+0024.05717e+00151.6000000000e+0024.56057e+00162.0000000000e+0024.91665e+00172.5000000000e+0024.93840e+00183.1500000000e+0025.89830e+00194.0000000000e+0026.10921e+001105.0000000000e+0026.30995e+001116.3000000000e+0026.40254e+001128.0000000000e+0026.06420e+001131.0000000000e+0036.56070e+001141.2500000000e+0036.38366e+001151.6000000000e+0036.54321e+001162.0000000000e+0036.51974e+001172.5000000000e+0037.21538e+001183.1500000000e+0037.75686e+001194.0000000000e+0037.67046e+001205.0000000000e+0037.06445e+001216.3000000000e+0036.63015e+001228.0000000000e+0036.67562e+001231.0000000000e+0046.37474e+001241.2500000000e+0046.33128e+001测点13的记录数据序号频率（Hz）声压级（dB）16.3000000000e+0012.60514e+00128.0000000000e+0013.12378e+00131.0000000000e+0024.26058e+00141.2500000000e+0023.62954e+00151.6000000000e+0023.85188e+00162.0000000000e+0024.20659e+00172.5000000000e+0024.51887e+00183.1500000000e+0025.79194e+00194.0000000000e+0025.92190e+001105.0000000000e+0026.05264e+001116.3000000000e+0026.37646e+001128.0000000000e+0026.74215e+001131.0000000000e+0037.10428e+001141.2500000000e+0037.28276e+001151.6000000000e+0037.10097e+001162.0000000000e+0037.41620e+001172.5000000000e+0037.13852e+001183.1500000000e+0037.12102e+001194.0000000000e+0037.50648e+001205.0000000000e+0037.21114e+001216.3000000000e+0036.59741e+001228.0000000000e+0036.77342e+001231.0000000000e+0046.21186e+001241.2500000000e+0046.42508e+001测点14的记录数据序号频率（Hz）声压级（dB）16.3000000000e+0012.76973e+00128.0000000000e+0013.00455e+00131.0000000000e+0024.06564e+00141.2500000000e+0023.70782e+00151.6000000000e+0024.20851e+00162.0000000000e+0024.41290e+00172.5000000000e+0024.64160e+00183.1500000000e+0025.55860e+00194.0000000000e+0025.65433e+001105.0000000000e+0025.87743e+001116.3000000000e+0026.08132e+001128.0000000000e+0026.59209e+001131.0000000000e+0036.98789e+001141.2500000000e+0037.14929e+001151.6000000000e+0037.17307e+001162.0000000000e+0037.08396e+001172.5000000000e+0036.86726e+001183.1500000000e+0037.18535e+001194.0000000000e+0038.28384e+001205.0000000000e+0037.81801e+001216.3000000000e+0036.69511e+001228.0000000000e+0036.81851e+001231.0000000000e+0046.60364e+001241.2500000000e+0046.34845e+001测点15的记录数据序号频率（Hz）声压级（dB）16.3000000000e+0013.04752e+00128.0000000000e+0013.06822e+00131.0000000000e+0023.71829e+00141.2500000000e+0023.85181e+00151.6000000000e+0024.43946e+00162.0000000000e+0024.68850e+00172.5000000000e+0024.75112e+00183.1500000000e+0024.94897e+00194.0000000000e+0025.28509e+001105.0000000000e+0025.82277e+001116.3000000000e+0026.35546e+001128.0000000000e+0026.40673e+001131.0000000000e+0036.76168e+001141.2500000000e+0036.96859e+001151.6000000000e+0036.91576e+001162.0000000000e+0037.21760e+001172.5000000000e+0037.28249e+001183.1500000000e+0037.20659e+001194.0000000000e+0037.65134e+001205.0000000000e+0036.95307e+001216.3000000000e+0036.66506e+001228.0000000000e+0036.78928e+001231.0000000000e+0046.45399e+001241.2500000000e+0046.48202e+001测点16的记录数据序号频率（Hz）声压级（dB）16.3000000000e+0012.96126e+00128.0000000000e+0012.85342e+00131.0000000000e+0023.90655e+00141.2500000000e+0023.67615e+00151.6000000000e+0023.88944e+00162.0000000000e+0024.10276e+00172.5000000000e+0024.38295e+00183.1500000000e+0025.09845e+00194.0000000000e+0025.62444e+001105.0000000000e+0025.94854e+001116.3000000000e+0026.19859e+001128.0000000000e+0026.24659e+001131.0000000000e+0037.01464e+001141.2500000000e+0036.61508e+001151.6000000000e+0036.62893e+001162.0000000000e+0037.04803e+001172.5000000000e+0037.47707e+001183.1500000000e+0037.11005e+001194.0000000000e+0037.67301e+001205.0000000000e+0037.58033e+001216.3000000000e+0037.03664e+001228.0000000000e+0036.62616e+001231.0000000000e+0046.29103e+001241.2500000000e+0046.42417e+001测点17的记录数据序号频率（Hz）声压级（dB）16.3000000000e+0012.50370e+00128.0000000000e+0012.75188e+00131.0000000000e+0023.84667e+00141.2500000000e+0023.54500e+00151.6000000000e+0023.95219e+00162.0000000000e+0024.19707e+00172.5000000000e+0024.57920e+00183.1500000000e+0025.70108e+00194.0000000000e+0025.91829e+001105.0000000000e+0025.97389e+001116.3000000000e+0026.49841e+001128.0000000000e+0027.07281e+001131.0000000000e+0037.25543e+001141.2500000000e+0036.94322e+001151.6000000000e+0036.86897e+001162.0000000000e+0037.17030e+001172.5000000000e+0037.17341e+001183.1500000000e+0037.45644e+001194.0000000000e+0037.55825e+001205.0000000000e+0036.87561e+001216.3000000000e+0036.73917e+001228.0000000000e+0036.82637e+001231.0000000000e+0046.58191e+001241.2500000000e+0046.58788e+001测点18的记录数据序号频率（Hz）声压级（dB）16.3000000000e+0012.71873e+00128.0000000000e+0012.96721e+00131.0000000000e+0023.86833e+00141.2500000000e+0023.79629e+00151.6000000000e+0024.45337e+00162.0000000000e+0024.52442e+00172.5000000000e+0024.69363e+00183.1500000000e+0025.27204e+00194.0000000000e+0025.37683e+001105.0000000000e+0025.60934e+001116.3000000000e+0026.03648e+001128.0000000000e+0026.55696e+001131.0000000000e+0037.32717e+001141.2500000000e+0037.43970e+001151.6000000000e+0037.21811e+001162.0000000000e+0037.07330e+001172.5000000000e+0037.51969e+001183.1500000000e+0037.90563e+001194.0000000000e+0038.08442e+001205.0000000000e+0037.28069e+001216.3000000000e+0036.69193e+001228.0000000000e+0036.75523e+001231.0000000000e+0046.75087e+001241.2500000000e+0046.30913e+001测点19的记录数据序号频率（Hz）声压级（dB）16.3000000000e+0017.76783e+00128.0000000000e+0017.87522e+00131.0000000000e+0028.43226e+00141.2500000000e+0028.01745e+00151.6000000000e+0028.11267e+00162.0000000000e+0028.06936e+00172.5000000000e+0028.14486e+00183.1500000000e+0028.27276e+00194.0000000000e+0028.35675e+00