直流電壓梯度檢測系統和密間隔管地電位檢測儀
英國進口原裝，全國現貨供應，我公司有10余年的DCVG/CIPS技術經驗，天津市嘉信技術工程公司是一家從事專業軟件開發、埋地管道檢測技術創新應用、腐蝕檢測儀器生產銷售的高科技企業。公司的經營理念是：走自主創新的道路，廣泛引進吸收國內外*技術、設備及管理經驗，堅持以市場開拓為導向、*研發為基礎，堅持不懈地打造公司的核心競爭力，致力為我國管道相關行業的技術及裝備提供優質服務。
When DC is applied to a pipeline in the same manner as in cathodic protection, a voltage gradient is established in the ground due to the passage of current through the resistive soil to the bare steel exposed at a coating fault.

The voltage gradient becomes larger and more concentrated the greater the current flowing and the closer you are to a coating fault location. In general, the larger the fault, the greater the current flow and hence bigger the voltage gradient.

The DC voltage gradient method uses a sensitive milli-volt meter, to indicate the potential difference between two copper/copper sulphate half cells placed in the soil in the voltage gradient at ground level. If spaced two metres apart in a voltage gradient, one half cell will adopt a more positive potential than the other, which thus enables the size of the gradient and direction of the current flow causing the voltage gradient to be established.

To make it easier to interpret and to separate what is being monitored from other DC sources such as long line cells, lurics, other CP systems, etc., in the DC Voltage Gradient Technique, the asymmetrical DC signal impressed onto the pipeline is switched ON and OFF at the rate of 0.45 seconds ON, 0.8 seconds OFF. The DC signal can be impressed on top of existing CP systems or the pipeline CP Transformer Rectifiers （T/R） can be switched by using a special interrupter inserted into the negative lead from the Transformer Rectifier.

The DC signal can even be injected at a test post using batteries or a portable DC generator and temporary ground bed.

In carrying out a survey, the surveyor walks the pipeline route testing at regular intervals with the probes in a position of one in front of the other, separated by one to two metres, parallel and preferably above the pipeline, （though not essential provided you can pick up the voltage gradient from faults in the pipeline route）. As a fault is approached, the surveyor will see the milli-volt meter start to respond to the ON/OFF pulsed current, which is either a coating fault or interference from another structure. When the fault is passed, the needle deflection compley reverses and slowly decreases as the surveyor moves away from the fault. By retracing, the position of the probes can be found where the needle shows no deflection, ie: a null. The fault is then sited midway between the two copper/copper sulphate half cells.

This procedure is repeated at right angles to the first set of observations and where the two midway positions cross is the epicentre of the voltage gradient. This is directly above the coating fault.

Once located a series of electrical measurements are made that allow the severity of the fault and its corrosion status to be determined.
    天津嘉信結合十多年DCVG/CIPS 檢測防腐層缺陷及陰極保護的應用經驗，應用*的微電子及數據庫等軟件開發技術，研發出多功能的密間隔檢測的靜態數據記錄系統CIPS-Logger，防腐層缺陷及陰保DCVG/CIPS中文檢測數據處理軟件系統 CIPS-DView，且獲得國家著作權證書。 解決了埋地鋼質管道檢測數據的記錄及防腐層檢測數據分析的問題，為廣大客戶提供了應用DCVG/CIPS檢測技術完成管道腐蝕與防護直接評價的有效工具。

技術指導：高工，