EN ISO 12937:2000

Foreword
1 Scope
2 Normative references
3 Principle
4 Chemicals and materials
5 Apparatus
6 Sampling and sample preparation
7 Apparatus preparation
8 Apparatus check test
9 Procedure
10 Calculation
11 Expression of results
12 Precision
13 Test report
Annex A (normative) Sample handling
Annex B (informative) Alternative test method using
                      volumetric determination
                      of sample size

This International Standard specifies a method for the direct determination of water in petroleum products boilingbelow 390 °C. It covers the mass fraction range 0,003 % (m/m) to 0,100%(m/m). It is not applicable to productscontaining ketones or to residual fuel oils.This International Standard may be applicable to lubricating base oils. However, the precision has not beenestablished for these materials.The precision given in clause 12 is based upon data obtained using dual-cell, dual-electrolyte systems.NOTE 1 A number of substances and classes of compounds associated with condensation or oxidation-reduction reactionsinterfere in the determination of water by Karl Fischer titration. In petroleum products, the most common interferences arehydrogen sulfide and mercaptan sulfur, however, mass fractions of these below 0,003 % (m/m) as sulfur will not causesignificant interference over the range 0,003 % (m/m) to 0,100%(m/m) water. Other organic sulfur compounds commonlypresent such as sulfides, disulphides and thiophenes, do not interfere.NOTE 2 An alternative procedure is provided for information in annex B for the direct determination of water over the range0,003 % (V/V) to 0,100 % (V/V) in petroleum products. The limitations under which this alternative volume measurement may beused are listed in annex B.NOTE 3 For the purposes of this International Standard, the terms "% (m/m)" and "% (V/V)" are used to represent the massand volume fraction of a material respectively.