公开(公告)号：US20030058108A1

公开(公告)日：2003-03-27

申请号：US09918719

申请日：2001-08-01

申请人： Radiodetection Limited

发明人： Richard W. Fling ,  Nicholas C. Hillman ,  Alasdair McPhee ,  Luigi Lanfranchi

IPC分类号： G08B013/14

CPC分类号： G01V3/081 ,  G01V15/00

摘要： Transmitted magnetic field signals useable for locating an underground object, and methods and systems for generating the same. The magnetic field signal has desired spectral characteristics. More specifically, the transmitted magnetic field signal includes a carrier component useable for locating an underground object. The carrier component has a carrier component frequency substantially equal to an integer multiple of 300 Hz. This guarantees that the carrier component frequency is substantially equal to an integer multiple of both 50 Hz and 60 Hz. Such a carrier component allows use of maximum information sidebands in environments that often include harmonically derived interference signals at regular 50 Hz (null0.1 Hz) or 60 Hz (null0.1 Hz) intervals caused by power lines. The transmitted magnetic field signal may also include at least one information sideband including sideband energy. A substantial portion of the sideband energy is contained between the carrier component frequency and a frequency spaced 50 Hz from the carrier component frequency.

摘要翻译： 可用于定位地下物体的传输磁场信号，以及用于产生地下物体的方法和系统。 磁场信号具有期望的光谱特性。 更具体地，传输的磁场信号包括可用于定位地下物体的载体部件。 载波分量具有基本上等于300Hz的整数倍的载波分量频率。 这确保载波分量频率基本上等于50Hz和60Hz的整数倍。 这种载波部件允许在通常包括由电力线引起的常规的50Hz（±0.1Hz）或60Hz（±0.1Hz）间隔的谐波导出的干扰信号的环境中使用最大信息边带。 传输的磁场信号还可以包括至少一个包括边带能量的信息边带。 边带能量的大部分被包含在载波分量频率和与载波分量频率间隔开50Hz的频率之间。

公开(公告)号：US11061061B2

公开(公告)日：2021-07-13

申请号：US16349894

申请日：2017-11-15

申请人： RADIODETECTION LIMITED

发明人： Mark Marsden ,  Peter Mann ,  Charles Alexander ,  Jeff Thompson

IPC分类号： G01R31/08

摘要： Methods, systems and locators for detecting faults in an insulation layer of an insulated conductor buried beneath a ground surface are described. The locator comprises a magnetometer arranged to detect a magnetic field generated by the alternating current and to generate a current signal on the basis of the detected magnetic field, and an Alternating Voltage Gradient receiver comprising a pair of probes arranged to make electrical contact with the ground surface, which is arranged to generate a voltage signal indicative of a voltage between the pair of probes. A processor is configured to substantially synchronously sample the current signal and the voltage signal. This enables improved detection of faults in the insulation layer of the insulated conductor.

公开(公告)号：US20200064390A1

公开(公告)日：2020-02-27

申请号：US16349894

申请日：2017-11-15

申请人： RADIODETECTION LIMITED

发明人： Mark MARSDEN ,  Peter MANN ,  Charles ALEXANDER ,  Jeff THOMPSON

IPC分类号： G01R31/08

摘要： Methods, systems and locators for detecting faults in an insulation layer of an insulated conductor buried beneath a ground surface are described. The locator comprises a magnetometer arranged to detect a magnetic field generated by the alternating current and to generate a current signal on the basis of the detected magnetic field, and an Alternating Voltage Gradient receiver comprising a pair of probes arranged to make electrical contact with the ground surface, which is arranged to generate a voltage signal indicative of a voltage between the pair of probes. A processor is configured to substantially synchronously sample the current signal and the voltage signal. This enables improved detection of faults in the insulation layer of the insulated conductor.

公开(公告)号：US20030052258A1

公开(公告)日：2003-03-20

申请号：US10288431

申请日：2002-11-06

申请人： Radiodetection Limited

发明人： Stuart John Russell ,  Andrew Biggerstaff Lewis ,  John Philip Dakin

IPC分类号： G01J004/00 ,  G02B006/27 ,  G02B006/26

CPC分类号： G02B6/447

摘要： In order to identify a fiber optic cable (10) a beam (14) of polarised light is caused to pass down the cable to a first site (A) at which an electromagnetic field (24) is applied to the cable (10). The electromagnetic field (24) traverses the cable (10) in an essentially transverse direction and has a time-varying component orientated along the length of the cable (10) at the first site (A), with the component varying so that the line integral thereof along the cable (10) is non-zero. This results in a variation in the polarisation of the light, which can the be detected by a polarisation discriminator (20) at a second site (B), thereby to identify the cable (10).

摘要翻译： 为了识别光纤电缆（10），使得偏振光束（14）将电缆穿过第一位置（A），在第一位置（A）处将电磁场（24）施加到电缆（10）。 电磁场（24）在基本横向上横穿电缆（10），并且具有沿第一位置（A）处的电缆（10）的长度方向定向的时变分量，其中部件变化，使得线 沿着电缆（10）的整体不为零。 这导致光的极化的变化，其可以由第二位置（B）处的偏振鉴别器（20）检测，从而识别电缆（10）。