prEN 13037

SLOVENSKI STANDARD
01-november-2025
Izboljševalci tal in rastni substrati - Določanje pH
Soil improvers and growing media - Determination of pH
Bodenverbesserungsmittel und Kultursubstrate - Bestimmung des pH-Wertes
Amendements du sol et supports de culture - Détermination du pH
Ta slovenski standard je istoveten z: prEN 13037
ICS:
65.080 Gnojila Fertilizers
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2025
ICS 65.080 Will supersede EN 13037:2011
English Version
Soil improvers and growing media - Determination of pH
Amendements du sol et supports de culture - Bodenverbesserungsmittel und Kultursubstrate -
Détermination du pH Bestimmung des pH-Wertes
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 223.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 13037:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Principle . 4
5 Reagents . 4
6 Apparatus . 5
7 Sampling . 5
8 Preparation . 5
9 Procedure . 5
9.1 Safety . 5
9.2 Suspension of material in solid form . 6
9.3 Suspension of material in pre-shaped form . 6
9.4 Suspension of liquid or pasty materials . 6
9.5 Measurement . 6
9.5.1 Calibration of the pH meter . 6
9.5.2 Measurement of the pH of solid samples . 6
9.5.3 Measurement of the pH of liquid and aqueous pasty samples . 6
10 Test report . 7
11 Validation of the method . 7
11.1 Validation in accordance with ISO 5725-2. 7
11.2 Performance characteristics. 7
Annex A (informative) Performance characteristics of the method . 8
Bibliography . 10

European foreword
This document (prEN 13037:2025) has been prepared by Technical Committee CEN/TC 223 “Soil
improvers and growing media”, the secretariat of which is held by NEN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 13037:2011.
— adaptation of scope and applicability with respect to the EU – Fertilizer Product Regulation [2].
This document has been prepared under a standardization request addressed to CEN by the European
Commission. The Standing Committee of the EFTA States subsequently approves these requests for its
Member States.
1 Scope
This document specifies an instrumental method for the routine determination of pH in a suspension of
soil improvers or growing media.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
CEN/TS 17732:2022, Soil improvers and growing media – Terminology
EN 12579:2024, Soil improvers and growing media - Sampling
prEN 13040-1:2025, Soil improvers and growing media — Sample preparation — Part 1: Sample
preparation for chemical and physical tests, determination of dry matter content, moisture content and
laboratory bulk density
3 Terms and definitions
For the purposes of this document, the terms and definitions given in CEN/TS 17732:2022 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
4 Principle
A sample is extracted with water at 22 °C ± 3,0 °C in an extraction ratio of 1 to 5 (1 V sample + 5 V water).
The pH of the suspension is measured using a pH meter.
5 Reagents
Use only reagents of recognized analytical grade.
5.1 Water with a specific conductivity not higher than 0,2 mS/m at 25 °C.
5.2 Buffer solution, pH = 4,00 at 20 °C.
Dissolve 10,21 g of potassium hydrogen phthalate (C H KO ) in water (5.1) and dilute to 1 000 ml in a
8 5 4
volumetric flask.
Commercially available buffers (e.g. in the form of tablets) covering the required pH may also be used.
5.3 Buffer solution, pH = 7,00 at 20 °C.
Dissolve 3,800 g of potassium dihydrogen phosphate (KH PO ) and 3,415 g disodium hydrogen
2 4
phosphate (Na HPO ) in water (see 5.1) and dilute to 1 000 ml in a volumetric flask.
2 4
The potassium dihydrogen phosphate shall be dried before use for 2 h at 115 °C ± 5 °C.
Commercially available buffers (e.g. in the form of tablets) covering the required pH may also be used.
5.4 Buffer solu
...