最近看到一份关于织带拉力测试标准,其中针对设备的要求有个备注,如下:
It is desirable that the capacity of the machine or the range selected be such that the force required to break the test specimen
is not less than 20% of the selected range of the machine.
大致意思是测试样品的拉力值应不低于设备最大量程的20%,英文原文为it is desirable,大家觉得这个是建议还是强制要求?