1.1本指南涵盖了使用电气或电化学方法在操作条件下对工厂设备中的金属进行在线腐蚀监测的程序。在所述限制范围内，这些试验方法可用于确定累积金属损失或瞬时腐蚀速率，间歇性或连续进行，而无需从工厂中拆除监测探头。 1.2包括以下试验方法:电阻试验方法A和极化电阻试验方法B。 1.2.1试验方法A提供了累积金属损失的信息，并推断了腐蚀速率。除第节所述外，本试验方法对剩余金属厚度作出响应。 1.2.2试验方法B基于测定瞬时腐蚀速率的电化学测量，但可能需要使用其他技术进行校准，以获得真实的腐蚀速率。 其主要价值是快速检测腐蚀速率的变化，这可能表明工艺环境中的不良变化。 1.3以国际单位制表示的数值应视为标准值。括号中的值仅供参考。 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全和健康实践，并确定监管限制的适用性。 5.6中给出了具体的预防说明。 ====意义和用途====== 一般腐蚀的特点是，在整个工厂、特定位置，甚至在特定探头上，腐蚀程度或多或少。因此，与质量损失试样一样，腐蚀速率的估计涉及探针表面的平均值。必须考虑到表面通常存在渗透性较大或较小的区域。 需要对探针元件、试样或电极进行目视检查，以确定这种可变性引起的测量干扰程度。当要检测腐蚀速率的相对变化时，这种可变性不那么关键。 本指南中所述的两种电气试验方法都提供了一种确定腐蚀速率的技术，而无需按照指南G 4中所述方法的要求物理进入系统取出试样 . 试验方法B具有在几分钟内提供腐蚀速率测量的额外优势。 这些技术在过程中断或其他问题可能造成腐蚀条件的系统中很有用。腐蚀性攻击的早期警报可以允许在工艺设备发生重大损坏之前采取补救措施。 当使用添加抑制剂来控制设备腐蚀时，这些技术也很有用。 腐蚀速率增加的指示可用于表示需要额外的抑制剂。 控制工艺设备中的腐蚀需要持续了解腐蚀速率。这些测试方法可用于以数字格式提供此类信息，便于传输到计算机进行分析。 试验方法A — 电阻 (1- 6. ) 4. 顶部

1.1 This guide covers the procedure for conducting online corrosion monitoring of metals in plant equipment under operating conditions by the use of electrical or electrochemical methods. Within the limitations described, these test methods can be used to determine cumulative metal loss or instantaneous corrosion rate, intermittently or on a continuous basis, without removal of the monitoring probes from the plant. 1.2 The following test methods are included: Test Method A for electrical resistance, and Test Method B for polarization resistance. 1.2.1 Test Method A provides information on cumulative metal loss, and corrosion rate is inferred. This test method responds to the remaining metal thickness except as described in Section. 1.2.2 Test Method B is based on electrochemical measurements for determination of instantaneous corrosion rate but may require calibration with other techniques to obtain true corrosion rates. Its primary value is the rapid detection of changes in the corrosion rate that may be indicative of undesirable changes in the process environment. 1.3 The values stated in SI units are to be considered standard. The values in parentheses are for information only. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in 5.6. ====== Significance And Use ====== General corrosion is characterized by areas of greater or lesser attack, throughout the plant, at a particular location, or even on a particular probe. Therefore, the estimation of corrosion rate as with mass loss coupons involves an averaging across the surface of the probe. Allowance must be made for the fact that areas of greater or lesser penetration usually exist on the surface. Visual inspection of the probe element, coupon, or electrode is required to determine the degree of interference in the measurement caused by such variability. This variability is less critical where relative changes in corrosion rate are to be detected. Both electrical test methods described in this guide provide a technique for determining corrosion rates without the need to physically enter the system to withdraw coupons as required by the methods described in Guide G 4 . Test Method B has the additional advantage of providing corrosion rate measurement within minutes. These techniques are useful in systems where process upsets or other problems can create corrosive conditions. An early warning of corrosive attack can permit remedial action before significant damage occurs to process equipment. These techniques are also useful where inhibitor additions are used to control the corrosion of equipment. The indication of an increasing corrosion rate can be used to signal the need for additional inhibitor. Control of corrosion in process equipment requires a knowledge of the rate of attack on an ongoing basis. These test methods can be used to provide such information in digital format easily transferred to computers for analysis. TEST METHOD A — ELECTRICAL RESISTANCE (1- 6 ) 4 Top