ISO 3405 pdf download – Petroleum products -Determination of distillation characteristics at atmospheric pressure

ISO 3405 pdf download – Petroleum products -Determination of distillation characteristics at atmospheric pressure.
3.12
thermometer reading
temperature recorded by the sensor of the saturated vapour, measured in the neck of the flask below the vapour tube and under the specified conditions of this test
3.13
temperature reading
thermometer reading or Other temperature measurement device reading which is corrected to 101.3 kPa barometric pressure
3.14
emergent-stem effect
offset in temperature reading caused by the use of a total immersion mercury-in-glass thermometer in the partial immersion mode
NOTE The emergent part of the merajry column is at a kwer temperature than the immersed po1ion, resulting in a lower temperature reading than that obtained with the thermometer completely immersed for calibration,
3.15
temperature lag
offset In temperature reading between a mercury.4n.glass thermometer and an electronic temperature- measurement device, caused by the different response times of the systems Involved
4 Principle
The sample is assigned to one of four groups, based on its composition and expected volatility characteristics, with each group defining the apparatus arrangement, condenser temperature and operational variables A 100 ml test portion is distilled under the specified conditions appropriate to the group Into which the sample falls, and systematic observations of thermometer readings and volumes of condensate recovered are made. The volume of the residue in the flask is measured, and the loss on distillation recorded. The thermometer readings are corrected for barometric pressure and the data are then used for calculations appropriate to the nature of the sample and the specification requirements.
5 Apparatus
5.1 General
Typical assemblies of the manual apparatus are shown in Figures 1 and 2. In addition to the basic components described In this clause, automated apparatus also are equipped with a system for measuring and automatically recording the vapour temperature and the associated recovered volume In the receiving cylinder.
Automated equipment manufactured in or after the year 1999 shall be equipped with a device for automaticaly shutting down power to the unit and for spraying an inert gas or vapour in the chamber where the distillation flask Is mounted In the event of fire.
NOTE Some causes 04 fire are breakage of the distitation flask, electrical shorts, and foaming arid spdling 04 liquid sample Itwough the top openrig of the flask.
Alternatively, place the sensor in a casing with the tç covered, so that the assembly, because of its adjusted thermal mass and conductivity, has a temperature lag tine similar to that of a mercury-in-glass thermometer.
In case of dispute, and unless otherwise agreed, the referee test shall be carried out using the specified mercury-in-glass thermometers.
A means of determináng the difference In lag time between an electronic temperature-measurement system and a mercury-in-glass thermometer is given in Annex B.
£9 Centring device
The temperature sensor shall be fitted through a snug-fining device designed to mechanically centre the sensor in the neck of the distillabon flask without vapour leakage The use of a cork or silicone rubber stopper with a hole dnlled through the centre is not acceptable for this purpose. Examples of acceptable centring devices are shown In Figures 6 and 7.
Centring devices different from those shown in FIgures 6 and 7 are also acceptable provided that they position and hold the temperature sensor in the middle of the neck of the disbllabon flask
NOTE When running tests by the manual method, products with a low initial boding point may have one or more temperature readings obscured by the centring device.
5.10 Barometer
The barometer shall be capable of measuring atmospheric pressure with an acctxacy of 0,1 kPa or better, at the same elevation relative to sea level as the apparatus in the laboratory. Do not take readings from aneroid barometers that are precorrected to give sea level pressures.
NOTE The barometer should ideally be located in the room in which the distillation is camed out.