BS ISO 6587:2021 pdf download – Paper, board and pulps — Determination of conductivity of aqueous extracts
This document specifies a method for the determination of the conductivity of aqueous extracts of paper, board or pulp, these extracts having been prepared by a hot or cold method.
The method is applicable to all kinds of paper, board and pulps, except for papers used for electrical purposes. For high purity papers used for electrical purposes, see method given in EN 60554-2.
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.
ISO 186, Paper and board — Sampling to determine average quality
ISO 287, Paper and board — Determination of moisture content of a lot — Oven-drying method
ISO 638-1, Paper, board, pulps and cellulosic nanomaterials — Determination of dry matter content by oven-drying method — Part 1: Materials in solid form
ISO 7213, Pulps — Sampling for testing
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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
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measure of the effect of the presence of dissolved substances in a solution to conduct electricity
Note 1 to entry: Conductivity does not measure the same solution properties as either osmolality or osmolarity and does not produce equivalent results. Conductivity only measures those substances that produce ions and does not measure dissolved substances that do not produce ions.
[SOURCE: ISO 18369-1:2017, 220.127.116.11]
A 2 g sample is extracted for 1 h with 100 ml of boiling or cold, distilled or deionized water. Measurement of the conductivity of the extract at 25 °C by means of a conductivity meter or resistance bridge, using alternating current.
5.1 Distilled or deionized water Distilled or deionized water shall be used throughout the test. The conductivity of the water shall not exceed 0,2 mS/m after boiling and cooling as specified in 8.2.2.
NOTE Usually, both distillation and deionization are required. Unless great care is exercised when distilling, and with the materials employed in the condenser and subsequent surfaces with which the condensed vapour would possibly come in contact, the distillate can fail to reach the required level of conductivity. When it is not possible to obtain water of the specified purity, water with a higher conductivity may be used, but the conductivity of the water used should be stated in the test report.
5.2 Potassium chloride, standard solutions Use potassium chloride (KCl) of recognized analytical reagent grade, powdered, or fine crystals. Dry for 2 h at 105 °C ± 2 °C and immediately prepare the following two solutions.
5.2.1 0,01 mol/l solution Dissolve 0,745 g of the potassium chloride in water having a conductivity not greater than 0,2 mS/m, and dilute to 1 000 ml.
5.2.2 0,001 mol/l solution Dilute 100 ml of the 0,01 mol/l solution (5.2.1) to 1 000 ml. Store the solutions in waxed glass bottles with ground glass stoppers. The conductivity values, in millisiemens per meter, of the two solutions, are given in Table 1.
The usual laboratory apparatus and, in particular, the following shall be used.
6.1 Flasks of chemically resistant glass, with ground glass joints, stoppers and efficient water cooled reflux condensers made of the same quality of glass. All glassware shall be carefully rinsed with boiling distilled or deionized water (5.1).
6.2 Electric heater, adjustable at least to 200 W.
6.3 Conductivity meter or resistance bridge, with measuring cells provided with black platinum electrodes of area approximately 1 cm 2 , and capable of indicating the conductance of an aqueous extract with an error of less than ±5 % in the frequency range of 50 Hz to 3 000 Hz.
6.4 Constant-temperature bath, capable of maintaining a temperature of 25 °C ± 0,5 °C.BS ISO 6587 pdf download.