ISO 22476-1:2022/DAM 1:2026(en)
ISO/TC 182
Secretariat: BSI
Date: 2025-11-20
Geotechnical investigation and testing — Field Testing — Part 1: Electrical cone and piezocone penetration test — Amendment 1
Reconnaissance et essais géotechniques — Essais en place — Partie 1: Essais de pénétration au cône électrique et au piézocône — Amendement 1
© ISO 2026
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Foreword
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The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Amendment 1 to ISO 18674‑3:2017 was prepared by Technical Committee ISO/TC 182, Geotechnics.
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This document was prepared by Technical Committee ISO/TC 182, Geotechnics, in collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC 341, Geotechnical Investigation and Testing, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
This amendment ISO22476-1:2022/Amd.1:2026(E) has been prepared to draw attention to known errors and ambiguities in normative requirements found to date (October 2025), for the following topics:
Cone penetrometer geometry;
Cone penetrometer calibration and verification.
A list of all parts in the ISO 22476 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www.iso.org/members.html.
Geotechnical investigation and testing — Field Testing — Part 1: Electrical cone and piezocone penetration test — Amendment 1
4.2 Cone penetrometer
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“The cone penetrometer shall have internal load sensors for the measurement of force on the cone (cone resistance), side friction on the friction sleeve (sleeve friction) and, if applicable, pore pressure at one or several locations on the surface of the cone penetrometer.”
With
“The cone penetrometer shall have internal load sensors for the measurement of force on the cone (cone resistance), side friction on the friction sleeve (sleeve friction) and, if applicable, a sensor for pore pressure at one or several locations on the surface of the cone penetrometer.”
4.4 Cone
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“The cross-sectional area of the cone shall be 1 000 mm2, which corresponds to a diameter of 35,7 mm”
With
“The nominal cross-sectional projected area of the cone shall be 1 000 mm2, which corresponds to a nominal diameter of 35,7 mm”
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” In this case, the geometry of the cone shall be adjusted proportionally to the diameter.”
With
” In this case, the dimensional tolerances given for a cone with nominal Ac=1 000 mm2 shall be linearly scaled in proportion to the nominal diameter.”
Delete
“If a filter is put at position u2, the diameter of the filter element itself shall be equal to the diameter of the cone, dc, with a tolerance of -0,1 mm to 0 mm (see also 4.5 and 4.6).”
4.5 Friction sleeve
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”The surface area, As, shall be 15 000 mm2
With
“The surface area of the sleeve friction shall be 15 000 mm2 for a cone with nominal Ac=1 000 mm2, which corresponds to dc=35,7 mm.”
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“ The geometry and tolerances of the friction sleeve shall be within the tolerance requirement, as shown in Figure 5.”
With
“ For a cone penetrometer with nominal surface area Ac=1 000 mm2, the geometry and dimensional tolerances of the friction sleeve shall be within the requirements given below.”
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With
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The cross-sectional area of the top end of the friction sleeve shall not be smaller than the cross-sectional area of the lower end.
With
The cross-sectional area of the top the friction sleeve (Ast) shall not be smaller than the cross-sectional area of the bottom of the friction sleeve (Asb).
4.6.2 Pore pressure u1
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“The surface of the filter shall fit the shape of the cone: it shall not protrude and shall not recess more than 0,1 mm.”
With
“At the start of the test, the surface of the filter shall fit the shape of the cone:
— shall not protrude from the shape of the cone.
— shall not recess more than 0,6 mm.”
4.6.3 Pore pressure u2
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“The filter element shall be placed in or just behind the cylindrical part of the cone. The diameter of the filter at the start of the test shall be equal to the diameter of the cylindrical part of the cone and the friction sleeve, with a tolerance limit of −0,1 mm to 0 mm.”
With
“The filter element shall be placed in the cylindrical part of the cone. The cylindrical part of the cone excludes the gap between the cone and the filter element. The diameter of the filter element dfil at the start of the test shall be as follows:”.
Replace
“(d2 − 0,1) ≤ dfil ≤ dc “
With
” (dc;min − 0,6) ≤ dfil ≤ dc
where dc;min is the minimum allowable diameter of the cone.
NOTE. The value of dc;min is 35,3 mm for a cone with a nominal diameter of 35,7 mm, see Figure 4.”
4.6.4 Pore pressure u3
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“The diameter of the filter shall correspond to the diameter of the friction sleeve with a tolerance limit of −0,1 mm to 0 mm, i.e. the diameter of the filter shall be smaller or equal to the diameter of the friction sleeve:”
With
“The diameter of the filter element dfil at the start of the test shall be as follows:”.
Replace
“(d2 − 0,1) ≤ dfil ≤ d2 “
With
” (d2;min − 0,6) ≤ dfil ≤ d2
where d2min is the minimum allowable diameter of the friction sleeve.”
5.1.2 Calibration and verification requirements
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“Calibration shall be carried out at least every twelve months or when sensors are overloaded or show signs of malfunction or if reference reading before the start of the test show a drift larger than 2 % of the full scale compared to the calibration zero load readings.”
With
“Calibration of a cone penetrometer shall be carried out at the earlier of:
— twelve months after the first use of a cone penetrometer for a cone penetration test
— up to the date and time when one of the sensors is overloaded
— after the cone penetrometer shows signs of malfunction, such as an anomalously significant difference between the zero values recorded during a test and those recorded during calibration.
The period before first use shall not exceed 12 months”.
5.1.3 Cone penetrometer class conformity assessment
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“The cone penetrometer shall meet all the requirements for each of the sensors for a given class to be achieved.”
With
“The cone penetrometer shall meet all the requirements for each of the sensors for a given cone penetrometer class to be achieved. The columns' ambient temperature stability and transient temperature stability (in Table 2) allow the choice of a parameter, e.g. Δaqc or Δaqcc. If values for both parameters are available, then the more favourable value may be used as input for the determination of the cone penetrometer class.”
5.3 Preparation of the test
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“When using class 0 cone penetrometers, the diameter of the cone and the sleeve shall be measured and recorded before the start of the test”
With
“For test category A, the diameter of the cylindrical part of the cone 
and the diameter of the friction sleeve 
shall be measured and recorded before the start of the test”
5.7 Registration of penetration length
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“The resolution of the penetration length measurement shall be at least 10 mm”
With
“The resolution of the penetration length measurement shall be less than or equal to 10 mm”.
6.1 Measured parameters
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“qc measured cone resistance; qc shall be expressed in units of pressure determined as the ratio between measured resistance force and cross-sectional area of the cone Ac; the cross-sectional area of the cone shall be measured before the start of the test when using class 0 cone penetrometers”
With
“qc measured cone resistance; qc shall be expressed in units of pressure determined as the ratio between measured resistance force and cross-sectional projected area of the cone 
; for test category A, 
shall be determined using measured values of 
according to 5.3”
Replace
“fs measured sleeve friction; fs shall be expressed in units of pressure determined as the ratio between measured resistance force and surface area of the friction sleeve; the surface area of the friction sleeve cone shall be measured before the start of the test when using class 0 cone penetrometers”
With
“fs measured sleeve friction; fs shall be expressed in units of pressure determined as the ratio between measured resistance force and surface area of the friction sleeve; the surface area of the friction sleeve 
; for test category A, 
shall be determined using measured values of 
according to 5.3”
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“T temperature”
With
“Ta apparent temperature, recorded by a temperature sensor in the cone penetrometer”.
7.3 Presentation of test results
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“ For test categories A and B, the cone resistance and sleeve friction shall be determined using the cone cross-section area and sleeve surface area calculated before the start of the test.
With
“ For test category A, the measured cone resistance and the measured sleeve friction shall be derived using the results of the geometry measurements required according to 5.3.
B.1.2 Wear of the cone penetrometer
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When using class 0 cone penetrometers, the cross-sectional area of the cone and the area of the sleeve friction shall be determined following the next procedure.
With
For test category A, the cross-sectional projected area of the cone and the surface area of the friction sleeve shall be determined as follows:
Replace
“
”
With
“ 
”
B.2.2 Measuring intervals for calibration
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“A measuring interval of interest of 0 °C to 15° C is typically selected for calibration”
With
“A measuring interval of interest of 0° to 15° is typically selected for calibration”
B.2.3.3 Assessment of calibration uncertainty
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“
”
With
“ 
”
B.2.3.4 Calibration results
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“- values of Ac and As selected for calculation of reference cone resistance qc;r (qc;r=Frqc/Ac), apparent cone resistance qc;a (qc;a=Fqc/Ac), reference sleeve friction fs;r (fs;r=Frfs/As) and apparent sleeve friction fs;a (fs;a=Ffs/As);
Nominal values may be selected for Ac and As. ”
With
“- values of Ac and As selected for calculation of reference cone resistance qc;r (qc;r=Frqc/Ac), apparent cone resistance qc;a (qc;a=Fqc/Ac), reference sleeve friction fs;r (fs;r=Frfs/As) and apparent sleeve friction fs;a (fs;a=Ffs/As), where nominal values may be selected for Ac and As;”
B.2.4.1 General
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“The calibration of the cone pressure sensor shall be conducted in a pressure vessel filled with water or gas. The reference consisting of a pressure sensor shall be capable of measuring pressure ur. A thermometer for measuring the temperature in the pressure vessel shall be used. The data acquisition unit(s) shall be able to record reference pressure, the output of the cone penetrometer sensors and temperature of the fluid in the pressure vessel.”
With
“The calibration of the cone pore pressure sensor shall be conducted in a pressure vessel filled with water or gas. The reference consisting of a pressure sensor shall be capable of measuring pressure ur. A thermometer for measuring the temperature in the pressure vessel shall be used. The data acquisition unit(s) shall be able to record reference pressure, the output of the cone penetrometer sensors and temperature of the fluid or gas in the pressure vessel.”
B.2.4.5 Calibration results
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“Test records shall include maximum and minimum temperature of the fluid in the pressure vessel, the interpolation formula, ur, ua, qc;a, and fs;a versus time at the recording frequency of B.2.4.2.”
With
“Test records shall include maximum and minimum temperature of the fluid or gas in the pressure vessel, the interpolation formula, ur, ua, qc;a, and fs;a versus time at the recording frequency of B.2.4.2.”
B.2.5.1 General
Replace
“The dimensional measurement shall be conducted with a measuring device with an expanded measurement uncertainty lower than 0,05.”
With
“The dimensional measurement shall be conducted with a measuring device with an expanded measurement uncertainty lower than 0,05 and a coverage factor k=2. “
B.2.5.2 Test method
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“The test method shall be as follows.”
With
“The test method shall be as follows, where applicable.”
B.2.7.2 Test method
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“— Record apparent cone resistance qc;a, apparent sleeve friction fs;a and, where applicable, apparent pore pressure ua and apparent temperature Ta throughout the test at ≥1 Hz.”
With
“— Record apparent cone resistance qc;a, apparent sleeve friction fs;a and, where applicable, apparent pore pressure ua and apparent temperature Ta recorded by a temperature sensor in the cone penetrometer throughout the test at ≥1 Hz.”.
Replace
“— Place the cone penetrometer in thermostat bath 1, so that the cone penetrometer reaches a uniform temperature of 30 °C throughout, defined as the earlier of:”
With
— During the verification procedure, place the cone penetrometer in thermostat bath 1 and thermostat bath 2, so that for each placement:
a) the apex of the cone is at least 10 mm above the bottom of the thermostat bath;
b) the fluid level of the thermostat bath coincides with the gap immediately above the friction sleeve.
— Place the cone penetrometer in thermostat bath 1, so that the cone penetrometer reaches a uniform temperature of 30 °C throughout, defined as earlier of:”.
Replace
“— Thereafter, quickly transfer the cone penetrometer to thermostat bath 2, so that
a) the apex of the cone is at least 10 mm above the bottom of the thermostat bath;
b) the fluid level of the thermostat bath coincides with the gap immediately above the friction sleeve.
With
” — Thereafter, quickly transfer the cone penetrometer to thermostat bath 2 and after 3 min, quickly return the cone penetrometer to thermostat bath 1.”
Delete
“- After 3 min, quickly return the cone penetrometer to the thermostat bath 1.”
B.2.7.3 Test results
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“The test records and test report shall include, where applicable:
— calibration report for the reference thermometer of thermostat bath 1 and the reference thermometer of thermostat bath 2;
— description of the apparatus and, if applicable, the test method(s) for temperature correction, for cone penetrometers that rely on real-time or post-processing correction for temperature influence on CPT results;
— temperatures of the thermostat baths, qc;a, qc;ac, fs;a, fs;ac, ua, uac and Ta versus time at the recording frequencies of B.2.7.2;”
With
“The test records shall include, where applicable:
— calibration report for the reference thermometer of thermostat bath 1 and the reference thermometer of thermostat bath 2;
— temperatures of the thermostat baths, qc;a, qc;ac, fs;a, fs;ac, ua, uac and Ta versus time at the recording frequencies of B.2.7.2.
The test report shall include, where applicable:
— graphical results of temperatures of the thermostat baths, qc;a, qc;ac, fs;a, fs;ac, ua, uac and Ta versus time for cone penetrometers that rely on real-time or post-processing correction for temperature influence on the results;
— description of the apparatus and if applicable, the test method(s) for temperature correction, for cone penetrometers that rely on real-time or post-processing correction for temperature influence on CPT results;”
B.2.8.1 General
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“The verification shall be performed in a frame capable of clamping the cone penetrometer horizontally with an independent loading device or means to apply a dead weight, capable of measuring a radial force Fr applied at the cylindrical part of the cone, where Fr is a static force between 90 N and 110 N with a standard uncertainty of < 1 N. The data acquisition unit(s) shall record the output of the cone penetrometer. Air temperature variations throughout the test shall not exceed ±3°.”
With
“The verification shall be performed in a frame capable of clamping the cone penetrometer horizontally. An independent loading device or means to apply a dead weight shall be used, capable of measuring a radial force Fr applied at the cylindrical part of the cone, where Fr is a static force between 90 N and 110 N with a standard uncertainty of < 1 N. The data acquisition unit(s) shall record the output of the cone penetrometer. Air temperature variations throughout the test shall not exceed ±3°.”
