non-contact thermometry,非接触测温法
non-crystalline electrode,非晶体电极
non-delimiter byte,非定界字节
non-destructive inspection,无损探伤
non-destructive inspection machine,无损探伤机
non-dimensional [relative] velocity,无量纲[相对]速度
non-dispersive infra-red gas analyzer;NDIR gas analyzer,非色散红外线气体分析器；
NDIR气体分析器
non-engineering system simulation,非工程系统仿真
non-enveloped thermistor,非密封型热敏电阻器
non-function type optic-fibre temperature transducer,非功能型光纤温度传感器
non-interacting control,无相关控制
non-interchangeable accessory,不可互换附件
non-isolated analogue input,非隔离的模拟输入
non-line conversion,非线性转换
non-linear damping,非线性阻尼
non-magnetic strain gauge,抗磁性应变计
non-Newtonian fluid,非牛顿流体
non-radioactive electron capture detector,无放射源电子捕获检测器
non-reference line imaginary real amplitude receiver,无参考线虚分量仪
non-relevant failure,非关联失效
non return magnetometer,无定向磁力仪
non rotational imaging,无旋转成象
non-selective radiator,非选择辐射体
non split stream injector,无分流进样器
non-uniformity of chart [paper] speed,纸速不均匀性
non-uniqueness,非唯一性
noncapacitive a.c.arc,非电容性交流电弧
nondeterminisitic control system,非确定性控制系统
nondeterministic model,非确定性模型
nondiffraction X-ray spectrometer,非衍射X射线光谱仪
nonequilibrium state,非平衡态
nonequilibrium system,非均衡系统
nonlinear characteristics,非线性特性
nonlinear control system,非线性控制系统
nonlinear control system theory,非线性控制系统理论
nonlinear estimation,非线性估计
nonlinear model,非线性模型
nonlinear prediction,非线性预报
nonlinear programming,非线性规划
nonlinear scale,非线性标度
nonlinear system simulation,非线性系统仿真
nonlinear vibration,非线性振动
nonlinear viscous damping,非线性粘性阻尼
nonlinearity,非线性
nonmetallic material testing machine,非金属材料试验机
nonreturn-to-zero (NRZ),不归零制
normal barometer,标准气压表
normal beam technique,垂直法
normal beam testing,垂直法
normal calomel electrode,当量甘汞电极
normal distribution,正态分布
normal flow rate,正常流量
normal modes,正态振型
normal operating conditions,正常工作条件
normal-phase liquid chromatography,正相液相色谱法
normal probe,直探头
normal station,普通站
normal stress,正应力
normal temperature strain gauge,常温应变计
normal thermometer,标准温度表
normalization method,归一法
normalization regulator,归一化调节器
normalized impedance,归一化阻抗
normalized mass spectrum,归一化质谱
normalized reactance,归一化电抗
normalized resistance,归一化电阻
normally closed solenoid valve,常关式电磁阀
normally open solenoid valve,常开式电磁阀
notch filter,节点滤波器
nozzle,喷嘴
n-th nodal unbalance,第n阶振型不平衡谐量
N-type oxide gas sensor,N型氧化物气敏元件
nuclear electric quadrupole moment resonance spectroscopy,核四极共振波谱法
Nuclear Instrument Module (NIM),核仪器模块
nuclear magnetic double resonance,核磁双共振（法）
nuclear magnetic resonance magnetometer,核磁共振磁强计
nuclear magnetic resonance spectroscopy;NMR spectroscopy,核磁共振波谱法
nuclear radiation thickness meter,核辐射厚度计
(nuclear)radiation transducer [sensor],（核）辐射式传感器
nuclei counter,计核器
nude source,裸式离子源
null measurement,指零测量
null method,零位法
null method of measurement,零位测量法；指零测量法；零差测量法
null reading method,零读法
number of degrees of freedom,自由度数
number of effective plate,有效板数
number of theoretical plate,理论板数
numeric key,数字键
numerical aperture (NA),数值孔径
numerical control,数值控制
numerical value (of a quantity),（量的）数值
nutating disc flowmeter,（章动）圆盘流量计
nutating flowmeter,章动流量计
nutrients,营养盐
nutrients analyzer for seawater,海水营养盐分析器
Nyquist plot,奈奎斯特图