There are currently various types of tracer wires on the market, such as copper clad steel, copper core PVC insulated cables (hereinafter referred to as copper core wires), copper clad aluminum, and so on. Which tracing line is better and more conducive to long-term tracing and positioning management of buried gas pipelines? It is necessary to test the performance of the tracing line in order to choose a more suitable tracing line. Therefore, we conducted tests on the commonly used tracer lines for the three types of PE gas pipelines mentioned above, providing reference for the selection of tracer lines for PE gas pipelines in terms of their conductivity, anti-corrosion treatment of tracer line joints, and strength.

示蹤線的測試原理

Testing principle of tracer lines

銅包鋼是由鋼芯線和緊密包覆其外的銅層構成金屬芯，外側為PE防腐層，銅起到傳導弱電信號的作用，鋼絲則起到支撐作用。銅芯電線一般由內層的銅芯線、中間層的絕緣包皮和外層的保護外皮組成。銅包鋁由鋁芯線和緊密包覆其外的銅層構成金屬芯，外層為PE防腐層。

Copper clad steel is a metal core composed of steel core wires and a tightly wrapped copper layer, with a PE anti-corrosion layer on the outer side. Copper plays a role in conducting weak electrical signals, while steel wire plays a supporting role. Copper core wires are generally composed of an inner layer of copper core wire, an insulating sheath in the middle layer, and an outer protective sheath. Copper clad aluminum consists of an aluminum core wire and a copper layer tightly wrapped around it to form a metal core, with an outer layer of PE anti-corrosion coating.

由于鋼質燃氣管道外層的防腐層為具有絕緣、防腐性能的塑料層或涂層，與銅包鋼、銅芯電線、銅包鋁等外層也為具有絕緣、防腐性能的塑料層結構相似。因此，我們將兩者等效，通過采用PCM管道電流衰減率法，對示蹤線防腐層平均絕緣質量進行檢測。檢測原理是向示蹤線施加某一頻率的電流信號，電流由示蹤線向遠方傳遞時會逐漸衰減。其衰減大小與示蹤線的塑料層的絕緣電阻率有關，示蹤線塑料層的平均絕緣電阻率越高，電流衰減就越慢，反之則衰減越快。

Due to the fact that the anti-corrosion layer of the outer layer of steel gas pipelines is a plastic layer or coating with insulation and anti-corrosion properties, similar in structure to the outer layers of copper clad steel, copper core wires, copper clad aluminum, etc., which also have insulation and anti-corrosion properties. Therefore, we equate the two and use the PCM pipeline current decay rate method to detect the average insulation quality of the trace line anti-corrosion layer. The detection principle is to apply a current signal of a certain frequency to the tracer line, and the current will gradually decay when transmitted from the tracer line to the distance. The magnitude of its attenuation is related to the insulation resistivity of the plastic layer of the tracer line. The higher the average insulation resistivity of the plastic layer of the tracer line, the slower the current attenuation, and vice versa, the faster the attenuation.