1.1 本试验方法适用于测定100 mg/L至100 000 mg/L，在水和废水中，包括微咸水和盐水（见 6.5 ). 可以通过适当稀释样品来确定更大的浓度或具有高悬浮固体的样品，或两者兼而有之。 1.1.1 由于分析是基于载气的氧气读数与引入样品时相比的变化（参见 4.1 )，测量范围是载气中氧气量的函数。所需的浓度范围越高，载气中所需的氧气就越多。在推荐的条件下，载气浓度应在最大所需氧气需求的两到四倍之间。 1.1.2 较低的测量范围受到基线氧检测器输出的稳定性的限制。该信号是渗透系统温度、载气流速、氧检测器温度和参考传感器电压的函数。综合起来，这些变量将最小推荐范围限制为2 mg/L至100 mg/L。 1.1.3 上限测量范围受载气中最大氧浓度（100 %). 在载气浓度为最大氧气需求量的两到四倍的推荐条件下，这将最大可能氧气需求量限制在250之间 000 mg/L至500 000 mg/L。 然而，作为水分析的实际应用，该测试方法将考虑最大范围为100 000mg/L。 1.2 本试验方法适用于在试验条件下可注入反应区的样品中所含的所有需氧物质。喷射器开口限制了可以喷射的颗粒的最大尺寸。如果存在水不溶性液体或固体的需氧物质，则可能需要进行初步处理。这些预处理方法在 附件A2 . 1.3 该试验方法特别适用于测量某些工业废水和工艺流中的需氧量。 它在监测二次污水排放方面的应用尚未建立。其用于监测天然水域的用途受到第节中定义的干扰的极大限制 6. . 1.4 除实验室分析外，本试验方法还适用于现场监测。固体预处理应用的样品调理技术见 附件A2 . 1.5 以国际单位制表示的数值应视为标准。本标准不包括其他计量单位。 1.6 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.7 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 5.1 需氧量参数的测量对于工艺废水的控制至关重要。生化需氧量（BOD）和化学需氧量（COD）分析仪具有长的时间周期，并且在COD分析仪的情况下使用具有固有处置问题的腐蚀性试剂。 总需氧量分析更快，大约3分钟，并且在分析中不使用液体试剂。 5.2 TOD可以与COD和BOD相关联，提供有效的在线控制。 5.3 TOD提供了几个功能，使其成为比使用总碳（TC）或总有机碳（TOC）分析仪进行碳监测更具吸引力的测量方法。TOD不受无机碳存在的影响。TOD分析还将表明消耗或贡献氧气的非碳材料。例如，氨、亚硫酸盐和硫化物的需氧量将反映在TOD测量中。此外，由于实际测量是氧消耗，TOD反映了化合物的氧化状态（即，尿素和甲酸的碳原子数相同，但尿素的氧需求量是甲酸的五倍）。

1.1 This test method covers the determination of total oxygen demand in the range from 100 mg/L to 100 000 mg/L, in water and wastewater including brackish waters and brines (see 6.5 ). Larger concentrations, or samples with high suspended solids, or both, may be determined by suitable dilution of the sample. 1.1.1 Since the analysis is based on the change in oxygen reading of the carrier gas compared to that when a sample is introduced (see 4.1 ), the measurement range is a function of the amount of oxygen in the carrier gas. The higher the desired concentration range, the more oxygen required in the carrier gas. Under recommended conditions, the carrier gas concentration should be between two to four times the maximum desired oxygen demand. 1.1.2 The lower measurement range is limited by the stability of the baseline oxygen detector output. This signal is a function of the permeation system temperature, carrier gas flow rate, oxygen detector temperature, and reference sensor voltage. Combined, these variables limit the minimum recommended range to 2 mg/L to 100 mg/L. 1.1.3 The upper measurement range is limited by the maximum oxygen concentration in the carrier gas (100 %). With the recommended conditions of carrier gas concentration being two to four times the maximum oxygen demand, this limits the maximum possible oxygen demand to between 250 000 mg/L to 500 000 mg/L. However, as a practical application to water analysis, this test method will consider a maximum range of 100 000 mg/L. 1.2 This test method is applicable to all oxygen-demanding substances under the conditions of the test contained in the sample that can be injected into the reaction zone. The injector opening limits the maximum size of particles that can be injected. If oxygen-demanding substances that are water-insoluble liquids or solids are present, a preliminary treatment may be desired. These pretreatment methods are described in Annex A2 . 1.3 This test method is particularly useful for measuring oxygen demand in certain industrial effluents and process streams. Its application for monitoring secondary sewage effluents is not established. Its use for the monitoring of natural waters is greatly limited by the interferences defined in Section 6 . 1.4 In addition to laboratory analysis, this test method is applicable to on-stream monitoring. Sample conditioning techniques for solids pretreatment applications are noted in Annex A2 . 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 The measurement of oxygen demand parameters is critical to the control of process wastewaters. Biochemical oxygen demand (BOD) and chemical oxygen demand (COD) analyzers have long time cycles and in the case of COD analyzers use corrosive reagents with the inherent problem of disposal. Total oxygen demand analysis is faster, approximately 3 min, and uses no liquid reagents in its analysis. 5.2 TOD can be correlated to both COD and BOD, providing effective on-line control. 5.3 TOD offers several features which make it a more attractive measurement than carbon monitoring using total carbon (TC) or total organic carbon (TOC) analyzers. TOD is unaffected by the presence of inorganic carbon. TOD analysis will also indicate noncarbonaceous materials that consume or contribute oxygen. For example, the oxygen demand of ammonia, sulfite and sulfides will be reflected in the TOD measurement. Also, since the actual measurement is oxygen consumption, TOD reflects the oxidation state of the chemical compound (that is, urea and formic acid have the same number of carbon atoms, yet urea has five times the oxygen demand of formic acid).