晶体控制次级频率标准测试装置的英文

crystal-controlled secondary standard frequency measuring equipment

• 晶体:    crystal; vitrella; ...
• 控制:    control; dominate; ...
• 次级:    secondary
• 频率:    frequency; rate
• 标准:    standard; criterio ...
• 测试:    test; testing; che ...
• 装置:    installation; devi ...