BS EN ISO 3104:2020 pdf – Petroleum products – Transparent and opaque liquids – Determination of kinematic viscosity and calculation of dynamic viscosity.
1 Scope This document specifies Procedure A, using manual glass viscometers, and Procedure B, using glass capillary viscometers in an automated assembly, for the determination of the kinematic viscosity, ν, of liquid petroleum products, both transparent and opaque, by measuring the time for a volume of liquid to flow under gravity through a calibrated glass capillary viscometer. The dynamic viscosity, η, is obtained by multiplying the measured kinematic viscosity by the density, ρ, of the liquid. The range of kinematic viscosities covered in this test method is from 0,2 mm 2 /s to 300 000 mm 2 /s over the temperature range –20 °C to +150 °C. NOTE The result obtained from this document is dependent upon the behaviour of the sample and is intended for application to liquids for which primarily the shear stress and shear rates are proportional (Newtonian flow behaviour). If, however, the viscosity varies significantly with the rate of shear, different results can be obtained from viscometers of different capillary diameters. The procedure and precision values for residual fuel oils, which under some conditions exhibit non-Newtonian behaviour, have been included. 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 3105, Glass capillary kinematic viscometers — Specifications and operating instructions ISO 3696:1987, Water for analytical laboratory use — Specification and test methods ASTM E1137, Standard Specification for Industrial Platinum Resistance Thermometers ASTM E2877, Standard Guide for Digital Contact Thermometers 3? Terms? and? definitions For the purposes of this document, the following terms and definitions apply.
4 Principle The time is measured for a fixed volume of liquid to flow under gravity through the glass capillary of a calibrated viscometer under a reproducible driving head and at a known and closely controlled temperature. The kinematic viscosity is the product of the measured flow time and the calibration constant of the viscometer. 5 Reagents and materials 5.1 Cleaning solution, strongly-oxidizing cleaning solution or alkaline cleaning solutions can be used. Alkaline cleaning solutions with a pH of greater than 10 are not recommended as they have been shown to change the viscometer calibration. If these are used, then the viscometer calibration should be verified to ensure there is no change. 5.2 Sample solvent, completely miscible a prewash with an aromatic solvent such as toluene or heptane might be necessary to remove asphaltenic material. When cleaning capillaries inside the bath, the boiling point of the cleaning solution shall be higher than the bath temperature. 5.3 Drying solvent, suitable and volatile at the used temperature. Filter before use. If moisture remains, use a drying solvent miscible with water (5.4). NOTE When cleaning capillaries inside the bath and if the bath temperature is higher than 50 °C, acetone is not suitable. 5.4 Water, deionized or distilled, conforming to Grade 3 of ISO 3696:1987. Filter before use.
6 Apparatus design and requirements 6.1 Drying tubes, consisting of a desiccant drying system, consisting of either externally mounted drying tubes or an integrated desiccant drying system designed to remove ambient moisture from the capillary tube. Ensure that they are packed loosely and that the desiccant is not saturated with water. 6.2? Sample? filter, micron screen or fretted (sintered) glass filter, no more than 75 µm. 6.3? Reagent? filter, micron screen or fretted (sintered) glass filter, no more than 11 µm. 6.4 Ultrasonic bath, unheated — with an operating frequency between 25 kHz to 60 kHz and a typical power output of ≤100 W, of suitable dimensions to hold container(s) placed inside of bath, for use in effectively dissipating and removing air or gas bubbles that can be entrained in viscous sample types prior to analysis. It is permissible to use ultra-sonic baths with operating frequencies and power outputs outside this range; however, it is the responsibility of the laboratory to conduct a data comparison study to confirm that results determined with and without the use of such ultrasonic baths does not materially impact results. 6.5 Manual apparatus 6.5.1 Glass capillary viscometer, calibrated in accordance with ISO 3105. The viscometer shall have a certificate of calibration provided by a laboratory that meets ISO/IEC 17025. The calibration constant should be checked before first use of the capillary and only changed if necessary.