計算室

信号強度と電圧の関係

信号強度電圧
S9+60dB50mV
S9+50dB15mV
S9+40dB5mV
S9+30dB1500μV
S9+20dB500μV
S9+10dB150μV
S950μV
S825μV
S712.5μV
S66μV
S53μV
S41.5μV
S30.75μV
S20.3μV
S10.15μV

S9で50μV S9+10dBで150μVです 約3倍
x=20\log{3}=9.54 約10dBです。

S9で50μV S9+30dbで1500μV 約30倍
x=20\log{30}=29.54 30dBです。

参考

log10 2 ≒ 0.3010
log10 3 ≒ 0.4771
log10 7 ≒ 0.8451

常用対数表 一覧

log0123456789
1.0.0000dB.0043.0086.0128.0170.0212.0253.0294.0334.0374
1.1.0414.0453.0492.0531.0569.0607.0645.0682.0719.0755
1.2.0792.0828.0864.0899.0934.0969.1004.1038.1072.1106
1.3.1139.1173.1206.1239.1271.1303.1335.1367.1399.1430
1.4.1461.1492.1523.1553.1584.1614.1644.1673.1703.1732
1.5.1761.1790.1818.1847.1875.1903.1931.1959.1987.2014
1.6.2041.2068.2095.2122.2148.2175.2201.2227.2253.2279
1.7.2304.2330.2355.2380.2405.2430.2455.2480.2504.2529
1.8.2553.2577.2601.2625.2648.2672.2695.2718.2742.2765
1.9.2788.2810.2833.2856.2878.2900.2923.2945.2967.2989
2.0.3010.3032.3054.3075.3096.3118.3139.3160.3181.3201
2.1.3222.3243.3263.3284.3304.3324.3345.3365.3385.3404
2.2.3424.3444.3464.3483.3502.3522.3541.3560.3579.3598
2.3.3617.3636.3655.3674.3692.3711.3729.3747.3766.3784
2.4.3802.3820.3838.3856.3874.3892.3909.3927.3945.3962
2.5.3979.3997.4014.4031.4048.4065.4082.4099.4116.4133
2.6.4150.4166.4183.4200.4216.4232.4249.4265.4281.4298
2.7.4314.4330.4346.4362.4378.4393.4409.4425.4440.4456
2.8.4472.4487.4502.4518.4533.4548.4564.4579.4594.4609
2.9.4624.4639.4654.4669.4683.4698.4713.4728.4742.4757
3.0.4771.4786.4800.4814.4829.4843.4857.4871.4886.4900
3.1.4914.4928.4942.4955.4969.4983.4997.5011.5024.5038
3.2.5051.5065.5079.5092.5105.5119.5132.5145.5159.5172
3.3.5185.5198.5211.5224.5237.5250.5263.5276.5289.5302
3.4.5315.5328.5340.5353.5366.5378.5391.5403.5416.5428
3.5.5441.5453.5465.5478.5490.5502.5514.5527.5539.5551
3.6.5563.5575.5587.5599.5611.5623.5635.5647.5658.5670
3.7.5682.5694.5705.5717.5729.5740.5752.5763.5775.5786
3.8.5798.5809.5821.5832.5843.5855.5866.5877.5888.5899
3.9.5911.5922.5933.5944.5955.5966.5977.5988.5999.6010
4.0.6021.6031.6042.6053.6064.6075.6085.6096.6107.6117
4.1.6128.6138.6149.6160.6170.6180.6191.6201.6212.6222
4.2.6232.6243.6253.6263.6274.6284.6294.6304.6314.6325
4.3.6335.6345.6355.6365.6375.6385.6395.6405.6415.6425
4.4.6435.6444.6454.6464.6474.6484.6493.6503.6513.6522
4.5.6532.6542.6551.6561.6571.6580.6590.6599.6609.6618
4.6.6628.6637.6646.6656.6665.6675.6684.6693.6702.6712
4.7.6721.6730.6739.6749.6758.6767.6776.6785.6794.6803
4.8.6812.6821.6830.6839.6848.6857.6866.6875.6884.6893
4.9.6902.6911.6920.6928.6937.6946.6955.6964.6972.6981
5.0.6990.6998.7007.7016.7024.7033.7042.7050.7059.7067
5.1.7076.7084.7093.7101.7110.7118.7126.7135.7143.7152
5.2.7160.7168.7177.7185.7193.7202.7210.7218.7226.7235
5.3.7243.7251.7259.7267.7275.7284.7292.7300.7308.7316
5.4.7324.7332.7340.7348.7356.7364.7372.7380.7388.7396
5.5.7404.7412.7419.7427.7435.7443.7451.7459.7466.7474
5.6.7482.7490.7497.7505.7513.7520.7528.7536.7543.7551
5.7.7559.7566.7574.7582.7589.7597.7604.7612.7619.7627
5.8.7634.7642.7649.7657.7664.7672.7679.7686.7694.7701
5.9.7709.7716.7723.7731.7738.7745.7752.7760.7767.7774
6.0.7782.7789.7796.7803.7810.7818.7825.7832.7839.7846
6.1.7853.7860.7868.7875.7882.7889.7896.7903.7910.7917
6.2.7924.7931.7938.7945.7952.7959.7966.7973.7980.7987
6.3.7993.8000.8007.8014.8021.8028.8035.8041.8048.8055
6.4.8062.8069.8075.8082.8089.8096.8102.8109.8116.8122
6.5.8129.8136.8142.8149.8156.8162.8169.8176.8182.8189
6.6.8195.8202.8209.8215.8222.8228.8235.8241.8248.8254
6.7.8261.8267.8274.8280.8287.8293.8299.8306.8312.8319
6.8.8325.8331.8338.8344.8351.8357.8363.8370.8376.8382
6.9.8388.8395.8401.8407.8414.8420.8426.8432.8439.8445
7.0.8451.8457.8463.8470.8476.8482.8488.8494.8500.8506
7.1.8513.8519.8525.8531.8537.8543.8549.8555.8561.8567
7.2.8573.8579.8585.8591.8597.8603.8609.8615.8621.8627
7.3.8633.8639.8645.8651.8657.8663.8669.8675.8681.8686
7.4.8692.8698.8704.8710.8716.8722.8727.8733.8739.8745
7.5.8751.8756.8762.8768.8774.8779.8785.8791.8797.8802
7.6.8808.8814.8820.8825.8831.8837.8842.8848.8854.8859
7.7.8865.8871.8876.8882.8887.8893.8899.8904.8910.8915
7.8.8921.8927.8932.8938.8943.8949.8954.8960.8965.8971
7.9.8976.8982.8987.8993.8998.9004.9009.9015.9020.9025
8.0.9031.9036.9042.9047.9053.9058.9063.9069.9074.9079
8.1.9085.9090.9096.9101.9106.9112.9117.9122.9128.9133
8.2.9138.9143.9149.9154.9159.9165.9170.9175.9180.9186
8.3.9191.9196.9201.9206.9212.9217.9222.9227.9232.9238
8.4.9243.9248.9253.9258.9263.9269.9274.9279.9284.9289
8.5.9294.9299.9304.9309.9315.9320.9325.9330.9335.9340
8.6.9345.9350.9355.9360.9365.9370.9375.9380.9385.9390
8.7.9395.9400.9405.9410.9415.9420.9425.9430.9435.9440
8.8.9445.9450.9455.9460.9465.9469.9474.9479.9484.9489
8.9.9494.9499.9504.9509.9513.9518.9523.9528.9533.9538
9.0.9542.9547.9552.9557.9562.9566.9571.9576.9581.9586
9.1.9590.9595.9600.9605.9609.9614.9619.9624.9628.9633
9.2.9638.9643.9647.9652.9657.9661.9666.9671.9675.9680
9.3.9685.9689.9694.9699.9703.9708.9713.9717.9722.9727
9.4.9731.9736.9741.9745.9750.9754.9759.9763.9768.9773
9.5.9777.9782.9786.9791.9795.9800.9805.9809.9814.9818
9.6.9823.9827.9832.9836.9841.9845.9850.9854.9859.9863
9.7.9868.9872.9877.9881.9886.9890.9894.9899.9903.9908
9.8.9912.9917.9921.9926.9930.9934.9939.9943.9948.9952
9.9.9956.9961.9965.9969.9974.9978.9983.9987.9991.9996

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Last-modified: 2023-10-31 (火) 09:13:39