Standard Test Method for Measurement of Oxidation-Reduction Potential (ORP) of Soil

Importancia y uso:

5.1 Soil ORP, in conjunction with other soil characteristics such as pH (see Test Method G51), and electrical resistivity (see Test Methods G57 and G187), is used to predict corrosion tendencies of buried metallic structures (for example, pipelines and culverts). The ORP of the soil is one of many factors that influence structure service life. Its measurement is used in the design of new buried structures and in the evaluation of existing buried structures.

5.2 Soil ORP is a time-sensitive measurement. For an accurate indication of soil corrosivity, the measurement should be made in-situ in the field or as soon as practicable after removal of the soil sample from the ground.

5.3 The user of this test method is responsible for determining the significance of reported ORP measurements. ORP alone should typically not be used in characterizing the corrosivity of a particular soil. ORP measurements are appropriate when evaluating oxygen related reactions.

5.4 ORP measurements can sometimes be quite variable and non-reproducible. This is related, in part, to the general heterogeneity of a given soil. It is also related to the introduction of increased oxygen into the sample after extraction. The interpretation of soil ORP should be considered in terms of its general range rather than as an absolute measurement.

5.5 ORP measurements can be used to determine if a particular soil has the propensity to support microbiologically influenced corrosion (MIC) attack. These measurements can also be used to provide an indication of whether soil conditions will be aerobic or anaerobic. Appendix X1 provides reference guidelines for general interpretation of ORP data.

Subcomité:

G01.10

Referida por:

G0162-23, G0218-19

Volúmen:

03.02

Número ICS:

13.080.30 (Biological properties of soil)

Palabras clave:

ORP; oxidation-reduction potential; soil;