S313.3 ASAE FEB04 Soil Cone Penetrometer
S T A N D A R D
ASABE is a professional and technical organization, of members worldwide, who are dedicated to advancement of engineering applicable to agricultural, food, and biological systems. ASABE Standards are consensus documents developed and adopted by the American Society of Agricultural and Biological Engineers to meet standardization needs within the scope of the Society; principally agricultural field equipment, farmstead equipment, structures, soil and water resource management, turf and landscape equipment, forest engineering, food and process engineering, electric power applications, plant and animal environment, and waste management. NOTE: ASABE Standards, Engineering Practices, and Data are informational and advisory only. Their use by anyone engaged in industry or trade is entirely voluntary. The ASABE assumes no responsibility for results attributable to the application of ASABE Standards, Engineering Practices, and Data. Conformity does not ensure compliance with applicable ordinances, laws and regulations. Prospective users are responsible for protecting themselves against liability for infringement of patents. ASABE Standards, Engineering Practices, and Data initially approved prior to the society name change in July of 2005 are designated as `ASAE', regardless of the revision approval date. Newly developed Standards, Engineering Practices and Data approved after July of 2005 are designated as `ASABE'. Standards designated as `ANSI' are American National Standards as are all ISO adoptions published by ASABE. Adoption as an American National Standard requires verification by ANSI that the requirements for due process, consensus, and other criteria for approval have been met by ASABE. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that a concerted effort be made toward their resolution. CAUTION NOTICE: ASABE and ANSI standards may be revised or withdrawn at any time. Additionally, procedures of ASABE require that action be taken periodically to reaffirm, revise, or withdraw each standard. Copyright American Society of Agricultural and Biological Engineers. All rights reserved. ASABE, 2950 Niles Road, St. Joseph, MI 49085-9659, USA ph. 269-429-0300, fax [phone], [e-mail]
ASAE S313.3 FEB04
Soil Cone Penetrometer
Proposed by the ASAE Cultural Practices Equipment Committee; approved by the ASAE Power and Machinery Division Technical Committee; adopted by ASAE as a recommendation December 1968; revised February 1971; reconfirmed December 1975; reclassified as a Standard December 1978; reconfirmed December 1980; revised February 1985; revised editorially and reconfirmed December 1989; reaffirmed December 1994; revised February 1999; reaffirmed February 2004.
1 Purpose and scope
1.1 The soil cone penetrometer (figure 1) is recommended as a measuring device to provide a standard uniform method of characterizing the penetration resistance of soils. The force required to press the 30deg circular cone through the soil, expressed in kilopascals, is an index of soil strength called the cone index. 1.2 The Standard is intended for the following purposes: 1.2.1 To provide a common method of constructing a device capable of measuring general soil mechanical conditions that facilitates the reporting and interpretation of soil data by different research workers. 1.2.2 To assist those who work with different soils and soil conditions and who need a measure of soil mechanical properties for comparative purposes. 1.2.3 To provide a common system of characterizing soil properties from which it may be possible to develop performance and prediction relationships. 1.3 The Standard serves only as a means of constructing a device to measure soil resistance to penetration, and does provide not specific soil values such as cohesion, angle of friction or coefficient of soil-metal friction. Since the measured results are influenced by the method of use, users should refer to ASAE EP542.
Figure 1 Soil cone penetrometer
4 Test apparatus and procedure
4.1 The hand-operated soil cone penetrometer shown in figure 1 has a cone and a graduated driving shaft. Two cone base sizes are recommended: 323 mm2, 20.27 mm diameter (0.5 in.2, 0.798 in. diameter) with 15.88 mm (0.625 in.) diameter shaft for soft soils (figure 1a); and 130 mm2, 12.83 mm diameter (0.2 in.2, 0.505 in. diameter) with 9.53 mm (0.375 in.) diameter shaft for hard soils (figure 1b). American Iron and Steel Institute, AISI 416 stainless steel, machined to a smooth finish 1.6 m (63 in.) maximum is recommended as a suitable initial cone finish. The 129 mm2 (0.2 in.2) base area cone is suitable for handoperated instruments on hard soil if the shaft does not exceed a length of 457 mm (18 in.). On extremely hard soils, a mechanically driven 323 mm2 (0.5 in.2) base area cone is suitable because of the stronger driving shaft. The overall form of the penetrometer equipment is not part of this Standard. Graduations on the driving shaft are 25.4 mm (1.0 in.) apart and are used to identify depth on hand-operated devices. The measuring device of hand-operated units should have a cone index capacity of approximately 2 MPa (290 psi) for the 320 mm2 (0.5 in.2) base area penetrometers and not exceed 5 MPa (725 psi) for the 129 mm2 (0.2 in.2) base area penetrometers in order to be suitable for most agricultural soil conditions. A direct readout of cone index is desirable. This Standard specifies two cone sizes. Nonstandard data should be reported but should be accompanied by a description of the nonstandard penetrometer and its method of use. In very soft soils when operating at great depths, care should be taken so the shaft does not drag. A smaller diameter shaft may be necessary in some cases. Penetrometer cones should be replaced when the base diameter wear exceeds 3% and therefore affects the cone index by 5%. A 1.5 mm (0.06 in.) shoulder on the base of the cone provides longer cone life without materially affecting accuracy of readings. Good judgment should be used to discard cones for other factors such as excessive bluntness, or abnormal wear. Soil conditions rapidly modify the cone shape and finish, but change in diameter is suggested as...