四线法：这是在三线法基础上的改进法。这种方法可以消除由于辅助地极接地电阻、测试引线及接触电阻引起的误差。仪器选择：目前市场支持此种方法的仪器比较多，其中以共立4105A-H接地电阻测试仪为代表。钳夹法：钳夹法分为单钳法和双钳法1双钳法:利用在变化磁场中的导体会产生感应电压的原理，用一个钳子通以变化的电流,从而产生交变的磁场,该磁场使得其内的导体产生一定的感应电压，用另一个钳子测量由此电压产生的感应电流,*用欧姆定律计算出环路电路值。
PV063R1K1T1NFR1
PV063R1K1T1NFHS
PV063R1K1T1NMM1
PV063R1K1T1NMRC
PV063R1K1T1NFWS
PV063R1K1T1NFRC
PV063R1K1T1NFF1
PV080L1K1T1NFFC
PV080R1K1B1NSLB
PV080L1K1T1NFHS
PV080R1L1T1MULC
PV080R1K1A1NFWS
PV080R1K1T1NFRL
PV080R1K1T1NGLA
PV080R1K1T1NMMC
PV080R1L8L3NULC
PV080R1L8T1NULC
PV092R1K8T1N001
PV092R1K1T1NFRZ
PV092R1K1T1NMM1
PV092R1K1T1NMRK
PV092R1K4T1NFHS
PV092R1K1T1NKLC
PV092R1K1T1VMMC
PV092R1L1T1WTCC
PV092R1K1T1NF
PV092R1D1T1NMMC
PV092R1K1T1NGLC
PV092R1K1T1NMF1
PV092R1K1T1WFR1
PV092R1K1T1NULZ
PV092R1K1T1NHLC
PV092R1K1T1NFFC
PV092R1K1A1NFWS
PV092R1K1T1NFHS
PV092R1K1T1NFF1
PV092R1K1T1NFWS
PV092R9K1T1NMMC
PV092R1K1T1NFR1
PV092R9K1T1NFWS
PV092R1K1T1N001
PV092R1K1T1EMMC
PV092R1K1S1NFWS
PV092R1K4T1NMR1
PV092R1L1L3WTCC
PV092R1K1T1NUPM
PV092R1K8T1NMMC
PV092R1K1T1VFDS
PV092R1K1T1NMRC
PV092R1K1T1WMM1
PV092R1K1T1PFDS
PV092R1K1T1WMRC
PV092R1K1A1NMMC
PV092R1K1T1NMMC
PV092R1K8T1VMMC
PV092R1K1T1NMMK
PV092L1K1T1NFWS
PV092R1K1T1NFDS
PV092R1K1T1NKLA
PV092L1K1T1NMMC
PV092R1K4T1NFR1
PV092R1K1T1NMFC
PV092R1K1T1N100
PV092R1K8T1NFWS
PV092R1K1JHNMMC
PV092R1K4T1NMMC
PV092R1K1A4WFRZ
PV092R1K1AYNMRZ
PV092R1K1T1WFDS
PV092R1K1T1NFRC
PV092R1K1T1NHCC
PV092R1D1T1VMMC
PV092R1K1T1NMRZ
PV092R1K1T1WMR1
PV092R1K1T1WMMC
PV092R1K1T1NMR1
PV092R1L1T1NMMC
PV092R1K1T1NFFP
PV092L1K1T1N001
PV092R1D1T1NGLC
PV092R1K1T1NMLA
PV092R1K4T1NFPD
PV092R1L1T1NFPD
PV092L1K1J1NFR1
PV092R1K1A1NSLA
PV140R1K1T1NFRL
PV140L1K8T1NSLC
PV140R1K1T1NTCB
PV140R1L1A1NF
PV140L9G3B1NTCC
PV140R1K1T1NWLA
PV140R1K1T1NSCA
PV140R1D3T1VFHS
PV140L1G1T1NFFP
PV140L1K1T1NFFC
PV140L1K1T1NFFP
PV140L1K1T1NFWS
PV140L1L1T1NWCC
PV140R1D1T1NFFC
PV140R1F1T1NFHS
PV140R1F1T1NYCC
PV140R1F3T1NFFC
PV140R1F3T1NFRP
PV140R1G1T1VFFC
PV140R1K1A1NSCC
PV140R1K1B1NFWS
PV140R1K1B1NUPG
PV140R1K1T1NFDS
PV140R1K1T1NFFC
PV140R1K1T1NFFD
PV140R1K1T1NFFP
PV140R1K1T1NFF1
PV140R1K1T1NFHS
PV140R1K1T1NF
PV140R1K1T1NFRC
PV140R1K1T1NFRD
PV140R1L1T1NUPG
PV140R1L1T1NWCC
PV140R1L4T1NUPG
PV140R1K1T1NMMC
PV140R1K1T1NMRK
PV140R1K1T1NMRZ
PV140R1K1T1NULC
PV140R1K1T1NWCC
PV140R1K1T1NWLC
PV140R1K1T1WMMC
PV140R1L1T1NMMC
PV140R9K1T1NUPZ
PV140R9L1LKNWCC
PV140R9K1A1NSLCK0173
PV140R9K1T1NFDSK0186
PV140R9K1T1NFFCK0011
PV140R9K1T1NFHSK0017
PV140R9K1T1NFRCK0107
PV140R9K1T1NFWSK0032
PV140R9K1T1NFWSK0155
PV140R9K1T1NKCCK0175
PV140R9K1T1NMLCK0081
PV140R9K1T1NSLCK0003
PV140R9K1T1WSCCK0072
PV140R9K4T1NFFPK0088
PV140R9K4T1NZCBK0154
PV140R9K4T1WFRPX5918
PV140L9G1T1NFFPK0083
PDM可根据经验数据提供是否需要维护的信息。另一种是维护过度。业主/运营商希望避免装置故障引起停机，对这些装置定时“预约”保养，没有考虑这样频繁的护养是否必要。尽管这种做法减少了突发停机，但成本极高。PDM能显著减少不必要的护养次数。CalMaSter实现预测性维护ABB的CalMaster流量系统的开发目的是帮助客户检查己安装的电磁流量计的精度与状况。这些流量计广泛用于多种工业，由于具有大体积容量和高精度，能测量数百万加仑/天的大容量电磁流量计被市政部门普遍采用，应用在水行业中，为监管权移交和收费提供准确数据。
