水平定向钻管线敷设工程防腐层电导率测试方法

1、附录 A 防腐层电导率测试方法对防腐层电导率进行测试，应采用下列仪器设备：1万用表 3 块：直流电压量程为0V 2V，直流电流最小量程为0 200；2 中断器 1 台：中断频率为 1s 断 /3s 通或 3s 断 /12s 通；3 滑动变阻器： 0 99999；4便携式铜 / 硫酸铜参比电极2 支；5 连接导线和鳄鱼夹若干；6 钢钎接地电极若干支；7 ZC-8土壤电阻率测量仪1 套；8 恒电位仪或 12V 铅酸蓄电池 2 块；9 对讲机 2 台。对防腐层电导率进行测试，应按下列步骤进行测量：1 宜采用 ZC-8 土壤电阻率测量仪四电极法测量穿越段两端土壤电阻率；2应连接临时阴极保护装置（图），

2、临时阳极地床距管道距离不应小于100m，应使恒电位仪或蓄电池的正极接地床，负极接管道；当采用蓄电池时，应将滑动变阻器串联接入蓄电池正极与临时阳极地床电路中；3 应将电流中断器和电流表分别串联接入恒电位或蓄电池负极与管道连接的电路中；4在穿越段两端应分别连接电压表正极，并应使硫酸铜参比电极连接电压表负极和接地同时应测量和记录两端的管地自然电位；图防腐层电导率测试接线图1- 恒电位仪； 2- 电流中断器；3- 直流电压表；4- 直流电流表； 5- 临时阳极地床； 6- 硫酸铜参比电极15 应接通临时阴极保护电源， 并应测量和记录穿越段两端通电路 （ Uon）和断路（ Uoff ）电位，同时应调整电

3、流输出，两端断路电位（Uoff ）应控制为 -850mV -1050 mV ，并应记录对应的输出电流；6 应按本规范第条第 5 款的方法重复测量 3 次。防腐层电导率计算应按下列步骤进行：1 1 测试点 a 和 b 的电位变化应按下列公式计算：Ua Ua,on Ua,off（ A.0.3-1）Ub Ub,on Ub,off（ A.0.3-2 ）式中： Ua a 点电位变化（ V）；Ub b 点电位变化（ V）；Ua,on a 点通路电位（ V）；Ub,on b 点通路电位（ V）；Ua,off a 点断路电位（ V）；Ub,off b 点断路电位（ V）；2 电位变化比应按下式计算：r （ A

4、.0.3-3）式中 :r 电位变化比。1 ）当电位变化比在 0.625 1.6 之间时，宜采用通用法进行计算评价。可将两段电位变化的算术平均值认为是管道穿越段的平均电位变化，其平均电位应按下式计算： U（平均）（ A.0.3-4）式中： U（平均） -a b 点电位的平均值（V）。管道穿越段的电导应按下式计算：g（ A.0.3-5）式中： g电导（ s）；I 电流变化（ A）。2 ）当电位变化比不在0.625 1.6 之间时，可采用电位或者电流衰减方法评价，电位衰减法和电流衰减法应按下式计算：电位衰减法： a /L(A.0.3-6)电流衰减法： a /L(A.0.3-7)式中： L测点 a 与

5、 b 之间的距离（ m）；2a 所测管段的衰减系数。3 管段电导应按下式计算：g=/r式中： r 单位长度管段的纵向电阻（）；g 所测管段漏失电导（ s）；a衰减系数。4平均电导应按下式计算：G=式中： G穿越段管道涂层的平均电导（s）；A 穿越段管道的表面积为，d 为管道外径（ m） ,L 为管道穿越长度（m）。5 穿越段管底深度的平均土壤电阻率应按下式计算：（平均） =式中：（平均）- 管底深度的平均土壤电阻率（·m） ；a- 管底深度 a 点的土壤电阻率（· m） ；b- 管底深度 b 点的土壤电阻率（· m） 。当计算 1000· cm 特定土壤

6、电阻率中的涂层标称电导率时，应按下式进行：Gn=；式中： Gn在电阻率为土壤中，标称电导率；G穿越段管道涂层的比平均电导（）。A 0.4 标准管道数据表可按表的规定确定。3表 A.0.4标准管道数据表管道外径管道壁厚重度电阻率电导率单位表面积mmin.mmin.Kg/mIb/ft· m · ftA/mv/mA/mv/mm2/mft2/ftm2/kmft2/mil63.52.5005.2320.2068.6165.790122.28137.2718.17826.8300.1990.65199.53.45673.032.8757.0100.27611.3997.66092.49

7、228.17210.81935.4960.2290.75229.43.97488.903.5005.4860.21611.2807.58093.40428.47010.70635.1250.2790.92279.34.8386.0200.23716.05710.79065.61720.00015.24050.0008.5600.33722.29314.98047.26314.40621.15869.416114.304.5007.9380.31333.84122.74031.1359.49032.118105.3750.3591.18359.16.2208.1790.32242.48728.5

8、6024.7997.55940.325132.2989.5250.37519.16933.04021.4296.53146.666153.1055.5630.21922.27814.97047.29514.41521.14469.3707.1120.28028.23018.97037.33211.37626.79487.905168.286.6257.9250.31231.35521.07033.60310.24229.76097.6370.5291.73528.79.1589.5250.37537.24925.03028.2868.62235.353115.98710.9730.43242.

9、53228.58024.7737.55140.367132.437219.088.6256.3500.25033.27522.36031.6649.65131.582103.6140.6882.26688.211.9207.9380.31333.84122.74031.1359.49032.118105.3754续表管道外径管道壁厚重度电阻率电导率单位表面积mmin.mmin.Kg/mIb/ft· m· ftA/mv/mA/mv/mm2/mft 2/ftm2/kmft 2/mil219.088.6258.1790.32242.48728.56024.7997.55940.3

10、25132.2980.6882.26688.211.9209.5250.37519.16933.04021.4296.53146.666153.1056.3500.25033.27522.36031.6649.65131.582103.6149.2710.36560.24140.48017.4905.33157.175187.581273.0510.7509.5250.37561.83341.55017.0405.19458.686192.5390.8582.81857.81192011.1250.43871.71448.19014.6924.47868.064223.30912.7000.5

11、0081.46254.74012.9343.94277.316253.6616.3500.25049.67533.38021.2106.46547.147154.6807.1370.28155.73137.45018.9055.76252.895173.540323.8512.7507.9380.31361.77341.51017.0565.19958.630192.3541.0173.341017176209.5250.37573.75349.56014.2864.35469.999229.65712.7000.50097.35565.42010.8223.29992.400303.1516

12、.3500.25054.63036.71025.6507.80439.055128.133355.6014.0007.9250.31267.97945.68020.5776.27248.598159.4421.1173.671117193509.5250.37581.20954.57017.2255.25058.056190.4715续表管道外径管道壁厚重度电阻率电导率单位表面积mmin.mmin.Kg/mIb/ft· m· ftA/mv/mA/mv/mm2/mft 2/ftm2/kmft2/mil6.3500.25062.57742.05022.3536.81344.73

13、6146.7717.9250.31277.92052.36017.9525.47255.704182.757406.4016 0001.2774.191277221209.5250.37593.12962.58015.0204.57866.577218.42916.6620.656159.977107.5008.7442.665114.366375.218457.2018 0006.3500.25070.52447.39019.8356.04650.417165.4101.4364.711436248806.3500.25078.47052.73017.8265.43356.098184.04

14、97.1370.28188.14359.23015.8704.83763.013206.736508.0020.0001.5965.241596276507.9250.31284.39356.71016.5755.05260.332197.9419.5250.375116.96978.60011.9593.64583.621274.346558.8022.0006.3500.25086.41758.07016.1874.93461.779202.6881.7565.761756304109.5250.375137.19392.19010.1963.10898.079321.780593.732

15、3.3751.8656.1218653231011.9130.469170.751114.7408.1922.497122.069400.4897.1370.281106.03171.25013.1924.02175.801248.691609.6024.0007.9250.312117.65479.06011.8893.62484.110275.9511.9156.281915331808.7380.344129.24686.85010.8233.29992.397303.1416续表管道外径管道壁厚重度电阻率电导率mmin.mmin.Kg/mIb/ft· m· ftA/

16、mv/mA/mv/m10.3120.406152.343102.3709.1822.799108.909357.31211.9130.469175.320117.8107.9792.432125.335411.204609.6024.00012.7000.500186.749125.4907.4902.283133.506438.01015.8750.625232.227156.0506.0231.836166.081544.6777.2390.285116.52378.30012.0053.65983.301273.2987.9250.312142.46195.7309.8192.99310

17、1.845334.136660.4026.0008.2550.325132.62489.12010.5473.21594.812311.0659.5250.375152.729102.6309.1592.792109.185358.22012.7000.500202.642136.1706.9032.104144.868475.2887.9250.312147.44799.0809.4782.892105.409345.8298.2550.325153.116102.8099.1362.785109.462359.12776230.0008.7380.344162.030108.8808.63

18、32.631115.835380.0359.1440.360169.590113.9608.2482.514121.239397.7669.5250.375176.570118.6507.9222.415126.229414.136单位表面积m2/mft2/ftm2/kmft2/mil1.9156.281915331802.0756.812075359402.3947.852394414707续表管道外径管道壁厚重度电阻率电导率mmin.mmin.Kg/mIb/ft· m· ftA/mv/mA/mv/m10.3120.406191.079128.4007.3212.2311

19、36.601448.16876230.00011.1250.438205.559138.1306.8052.074146.953482.12912.7000.500234.429157.5305.9671.819167.592549.8438.7380.344194.800130.9007.1812.189139.261456.8949.5250.375212.330142.6806.5882.008151.794498.01010.3120.406229.816154.4306.0871.855164.294539.02311.9130.469264.713177.8805.2841.611189.242620.873914.436.00012.7000.500282.110189.5704.9581.511201.679661.67514.2750.562316.814212.8904.4151.346226.488743.07215.8750.625351.398236.1303.9811.213251.213824.18817.4500.687385.849259.2803.6251.105275.841904.9919.5250.375248.120166.7305.6381.71817