Tiêu chuẩn quốc tế

• Số hiệu / Standard Number: AASHTO T 194:1997
• Năm ban hành / Publication date: 1997
• Tình trạng / Status: A - Còn hiệu lực
• Tên tiếng Anh / Title in English: Standard Method of Test for Determination of Organic Matter in Soils by Wet Combustion
• Thay thế cho / Replace: AASHTO T194:1997
• Số trang / Page: 5

Phạm vi áp dụng / Scope of standard

The Wet Combustion method for the determination of soil organic matter is most applicable when it is desired to determine the humus-like, easily oxidized organic material to provide information relating to the suitability of the soil for plant growth. The method provides a good estimate of this type of organic matter, and, when the soil contains only this type, it can also provide a good estimate of the total organic content. However, the reagents used react only very slightly with fresh plant materials such as wood, roots, grass, and weed tops, etc., or with hydrocarbons, charcoal, lignite, coal, and the organic remains in ancient sediments. If such materials are present and the total organic matter is to be determined, the Loss on Ignition method found in T 267 must be used.

The following applies to all specified limits in this standard: For the purposes of determining conformance with these specifications, an observed value or a calculated value shall be rounded off "to the nearest unit" in the last right-hand place of figures used in expressing the limiting value, in accordance with ASTM E29, Using Significant Digits in Test Data to Determine Conformance with Specifications.

The values stated in SI units are to be regarded as the standard.

Refer to 29 CFR 1910.1200 for regulatory information for chemicals.