BS/EN 12596-2014 pdf download.Bitumen and bituminous binders – Determination of dynamic viscosity by vacuum capillary.
Details of design and construction of the AIVV are shown in Figure A.2. The size numbers, approximate capillary radii, approximate calibration factors, K, and viscosity range for the series of AIVV are given in Table A.2.
This viscometer has measuring bulb, B, bulb C and bulb D, located on the viscometer arm, M, which is a precision bore glass capillary. The measuring bulbs are 20 mm long capillary segments defined by timing marks F, G, H and I.
5.1.4 Modified Koppers vacuum capillary viscometer (MKVV)
The MKW is available in five sizes (see Table A.3) covering a range between 4,2 Pas to 20 000 Pa’s. Sizes 50 to 200 are best suited to viscosity measurements of bituminous binders at 60 °C.
Details of design and construction of the MKW are shown in Figure A.3. The size numbers, approximate capillary radii, approximate calibration factors, K, and viscosity ranges for the series of MKW are given in Table A.3.
This viscometer consists of a separate filling tube, A, and precision-bore glass capillary vacuum tube, M. These two parts are joined by a borosilicate ground glass joint. N, with a 24140 standard taper. Measuring bulb B, bulb C and bulb 0, on the glass capillary are 20 mm long capillary segments, defined by timing marks F. G, H and I.
5.1.5 Holder, made by drilling two holes. 22mm and 8mm internal diameter, through a No.11 rubber stopper. The centre-to-centre distance between holes shall be 25 mm Slit the rubber stopper between the holes and between the 8 mm hole and edge of the stopper. When placed in a 51 mm diameter hole in the bath cover, the stopper shall hold the viscometer in place. For the MKW the viscometer holder can be made by drilling a 28 mm hole through the centre of a No. 11 rubber stopper and slitting the stopper between the hole and the edge.
Sensors based on platinum resistance thermometers have been found suitable but other principles are also allowed. The thermal response time of the sensor shall be comparable with the former used reference (see informative Annex C). The temperature measuring device shall be calibrated regularly.
A solid stem mercury thermometer (which used to be the former reference thermometer as described in Annex C) is also allowed if national regulations permit its use.
The specified thermometers shall be standardized at total immersion; that is immersion to the top of the mercury column with the reminder of the stem and the expansion chamber at the top exposed to room temperature. The practise of completely submerging the thermometer is not recommended. When thermometers are completely submerged, corrections for each individual thermometer based on calibration under conditions of complete submergence are determined and applied. If the thermometer is completely submerged in the bath during use, the pressure of the gas in the expansion chamber will be higher or lower than during standardization, and can cause a high or low reading on the thermometer. It is essential that liquid-in-glass thermometers are calibrated periodically and those official corrections be adjusted as necessary to conform to any changes in temperature readings. The thermometer shall be read, estimating the reading to 0,1 °C. Thermometers should be checked at regular intervals. A commonly used procedure given in method ASTM E77 (2) applies a correction that is based on changes in the ice point calibration.
When measuring and controlling nominally constant temperatures, as in this test method, the thermal response time can be rather high (e.g. slow response to a change in temperature). Care shall be taken to consider this aspect since low thermal response time of the sensor can indicate greater cyclic variations than the bituminous material in practise experiences
5.3 Bath, suitable for immersion of the viscometer so that the liquid reservoir or the top of the capillary whichever is uppermost, is at least 20 mm below the top of the bath level, and with provisions for visibility of the viscometer and the thermometer. Firm supports for the viscometer shall be provided, or the viscometer shall be an integral part of the bath. The efficiency of the stirring and the balance between heat losses and heat input shall be such that the temperature of the bath medium does not vary by more than 0.5 °C over the length of the viscometer, or from viscometer to viscometer in the various bath positions.BS/EN 12596-2014 pdf download.
BS/EN 12596-2014 pdf download
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