Polytetrafluoroethylene (PTFE) tubing for aerospace applications — Methods for the determination of the density and relative density
航空航天用聚四氟乙烯(PTFE)管——密度和相对密度的测定方法
Specifies three methods: Method A - density gradient column method without a preconditioning heating and cooling cycle; method B - displacement of water and determination of change of weight method; method C - density gradient column method with a preconditioning heating and cooling cycle.