直流电压梯度检测系统和密间隔管地电位检测仪
英国进口原装，全国现货供应，我公司有10余年的DCVG/CIPS技术经验，天津市嘉信技术工程公司是一家从事专业软件开发、埋地管道检测技术创新应用、腐蚀检测仪器生产销售的高科技企业。公司的经营理念是：走自主创新的道路，广泛引进吸收国内外*技术、设备及管理经验，坚持以市场开拓为导向、*研发为基础，坚持不懈地打造公司的核心竞争力，致力为我国管道相关行业的技术及装备提供优质服务。
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.
    天津嘉信结合十多年DCVG/CIPS 检测防腐层缺陷及阴极保护的应用经验，应用*的微电子及数据库等软件开发技术，研发出多功能的密间隔检测的静态数据记录系统CIPS-Logger，防腐层缺陷及阴保DCVG/CIPS中文检测数据处理软件系统 CIPS-DView，且获得国家著作权证书。 解决了埋地钢质管道检测数据的记录及防腐层检测数据分析的问题，为广大客户提供了应用DCVG/CIPS检测技术完成管道腐蚀与防护直接评价的有效工具。

技术指导：高工，