取样就是用取油工具从管线上或油箱中抽取润滑油(或液压油)样。取样操作必须保证所取的油样含有能反映机器工况变化的磨损颗粒，只有这样才能通过铁谱分析做出正确的判断。因此，取样时应遵循以下几条原则：
Sampling is the extraction of lubricant (or hydraulic) samples from pipelines or tanks using an oil extraction tool. Sampling operation must ensure that the oil sample contains wear particles which can reflect the changes of machine working conditions. Only in this way can the correct judgment be made through ferrography analysis. Therefore, the following principles should be followed in sampling:
①应尽量选择在润滑油过滤之前并避免从死角、底部取样;
It is necessary to select as much as possible before the filtration of lubricating oil and avoid sampling from dead angle and bottom.
②应尽量选择在机器运转时，或刚停机时取样;
(2) Sampling should be selected when the machine is running or just stopped.
③应始终在同一位置、同一条件下(如停机则应在相同的时间后)和同一运转状态(转速、载荷相同)下取样;
(3) Sampling should always be carried out at the same position, under the same conditions (after the same time if the machine stops) and under the same running state (same speed and load);
④取样周期应根据机器的性质和对状态检测要求来确定。机器在新投入运行或刚经解体检修，其取样间隔应短，通常应隔几小时取样一次，以监测分析整个磨合过程;机器进入正常运行阶段后，取样间隔可加大;此后，当发现磨损发展很快时，又应缩短取样时间间隔。
(4) The sampling period should be determined according to the nature of the machine and the requirement of state detection. The sampling interval of the machine should be short when it is newly www.diandongmenc.net.cnwww.chongyajiann.com.cnwww.xinzhouyanglao.cnput into operation or www.diandongmenc.com.cnwww.chongyajiann.cnwww.yanglaoyuanc.com.cnhas just been dismantled and repaired. Usually it should be taken every few hours to monitor and analyze the whole running-in process. When the machine enters the normal operation stage, the sampling interval can be increased. After that, when it is found that the wear develops rapidly, the sampling interval should be shortened.