N.T.C.thermistor,负温度系数热敏电阻器

Nansen bottle,南森采水器

Nansen opening-and-closing net,南森开团式网

narrow-band filter,窄带滤波器

narrow-band random vibration,窄带随机振动

narrow band spectrum,窄波段

national satellite,国土卫星

national standard,国家标准

natural convection,自然对流

natural electric-field method instrument,自然电场法仪器

natural environment,自然环境

natural field electro-detector,天然场电测仪

natural frequency,固有频率

natural frequency measurement,固有频率的测量

natural frequency of rotor/bearing system,转子支承系统固有频率

natural gamma spectromenter of logger,自然伽玛能谱测井仪

natural inherent frequency,自然固有频率

natural mode of vibration,固有振型

near field,近场

near infrared range(NIR)remote sensing,近红外遥感

near-optimality,近优性

nearest-neighbor,最近邻

nebulizer,雾化器

negative feedback,负反馈

negative knives linear,负刀联线

negative pressure,负压；真空

negative shock response spectrum,负冲击响应谱

negative strain,负应变

negative tempperature coefficient thermistor,负温度系数热敏电阻

nephelometer,浑浊度表

nephoscope,测云器

Nernst equation,能斯特方程

nest,嵌套

net pyrgeometer,净地球辐射表

net pyrradiometer,辐射平衡表

net radiation,净辐射；辐射平衡；辐射差额

net retention time,净保留时间

net retention volume,净保留体积

net sounder,网位仪

net terrestrial radiation,净地球辐射

network frame,网络帧

network management,网络管理

network model,网络模型

network protocol,网络协议

network technique,网络技术

neutral absorption,中性吸收

neutral filter,中性滤光片

neutral zone,中间区

neutrally buoyant float,中性浮标

Newton's fluid,牛顿流体

neutron dosimeter,牛顿流动定律

neutron dosimeter,中子剂量计

neutron logging instrument,中子测井仪

neutron fraiograghy,中子射线照相术

neutron spectromenter,中子能谱仪

neutron-gamma radiometer,中子伽玛辐射仪

Nickel-Chromium/CopperNickel thermocouple,镍铬-铜镍热电偶

Nickel-Chromium/NickelAluminium[Silicom] thermocouple，镍铬-镍铝[硅]热电偶

Nickel-Chromium-Silicom/Nickel-Silicom thermocouple,镍铬硅镍硅热电偶

Nier-Johnson geometry mass spectrometer,尼尔-约翰逊型 双聚焦质谱计

NIM bin NIM,机箱

Niskin sterile water sampler,尼斯金无菌采水器

nitrile rubber(Buna N),丁晴橡胶

nitrogen dioxide trnsfer furnace,二氧化氮转化炉

nitrogen-oxide analyzer,氮氧化物分析仪

NMR absorption band,核磁共振吸收带

NMR absorption line,核磁共振吸收线

NMR equipment,核磁共振仪

NMR line width,核磁共振线宽

no-load,空负荷

no-load test,空载试验

node,节点

noetic science,思维科学

noise,噪声

noise dose,噪声剂量

noise dose meter,噪声剂量计

noise factor,噪声系数

noise generator,噪声发生器

noise level,噪声电平

noise level analyzer,噪声级分析仪

noise prediction,噪声预估

noise room,噪声室

noise suppressing varistor,消噪电压敏电阻器

noise thermometer,噪声温度计

noise transducer [sensor],噪声传感器

nominal cartridge diameter of microphone,传声器极头公称直径

nominal characteristic,名义特性

nominal flow-rate,公称流量

nominal heat value,标定热值

nominal humidity,标称湿度

nominal operating condition,正常工作条件

nominal pressure rating,公称压力

nominal range,标称使用范围；标称量限

nominal range of use,标称使用范围

nominal size,公称通径

nominal temperature,标称温度

nominal travel,标称行程

nominal value,标称值

nominal voltage ratio,标称电压比

non-conformity,不合格

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