ASTM D623-99 pdf free.Standard Test Methods for Rubber Property-Heat Generation and Flexing Fatigue In Compression.
Check the machine for proper adjustment and therequired test conditions. Place the necessary weights on therear hanger to give the desired load.
If a stroke other than 4.45 mm (0.175 in.) used inadjusting the machine (8.2) is desired, then a new zero settingwill be required on the micrometer after adjusting the eccentricto the new stroke.Proceed as outlined in 8.2 to obtain the zerosetting.
For elevated temperatures requiring the use of theoven, allow a minimum of 2 h for preheating and equilibriumprior to start of the test. Maintain the lower anvil at the zerosetting, that is, 67 mm (2 5/s in.) above the loading lever (8.1)during the conditioning period.
Measure and record the height of the specimen. Mea-sure and record the indentation hardness. When the oven is tobe used, place the specimen in the oven on the platform,withthe small end of the cut specimen down. Condition for aminimum of 20 min before the start of the test.
Before starting the test, equilibrium of the lower platentemperature with the ambient should be assured. With theupper anvil or cross bar in its highest position，lower thebottom anvil and quickly position the specimen thereon,inverting its position from that used during the warm-upperiod.
Raise the lower anvil by means of the micrometer untila firm contact is established with the upper anvil or hammer.Remove the locking pin and apply the load.Then advance themicrometer until the beam is again restored to its original levelcondition as determined by the indicator.
If the specimen had an original height of exactly 25.4mm (1.000 in.),then the micrometer reading may be usedwithout correction for the compression height.For a smooth start,restore the pin to the lockedposition of the loading lever, and back off the micrometer threeto four turns. Then loosen the pin,start the machine, andremove the pin completely. Immediately restore the beam tothe level position by means of the micrometer and record thereading. Subject this reading to the same corrections as usedfor the static measurements.If the initial runningdeflection is less than one half of the impressed stroke or doesnot exceed this value within 1 or 2 min of the start,anunreliable and misleading heat rise will be obtained. Theloading lever must be maintained in a level position throughoutthe test.The ambient air temperature and the temperature ofthe lower anvil shall be at the steady state before starting thetest.ASTM D623 pdf download.