英国牛顿N4L公司（Newtons4th Ltd.,简称N4L）是一家专业的仪器设计和制造的高科技公司，牛顿Newtons4th (N4L)公司主要致力于在两大产品领域做到极致：PPA系列功率分析仪和PSM系列频率响应分析仪； 英国牛顿Newtons4th (N4L)公司所生产的功率分析仪和频率响应分析仪自推出以来，在全球赢得了多家认证机构的赏识和信赖，在功率分析仪领域，牛顿Newtons4th (N4L)是全球第一家取得ISO17025认证的功率分析仪厂商，牛顿Newtons4th (N4L)出货的每一台PPA系列功率分析仪随货均附带全球认可的ISO17025标准的可追溯性的校准报告。

英国牛顿Newtons4th (N4L)公司面对的主要客户群体是：高等院校，认证中心，质检中心，电源企业，LED照明企业，新能源汽车企业，电机检测，电机设计和制造企业等。

英国牛顿Newtons4th (N4L)公司设计和生产的高品质功率分析仪，拥有全球绝对的领先技术优势，产品除在英国本土大批量销售外，还远销欧洲，北美洲，亚洲和非洲等多个国家和地区。

英国牛顿Newtons4th (N4L)公司的功率分析仪产品线分：PPA500，PPA1500，PPA3500，PPA4500和PPA5500五大系列。其中：
1. PPA500系列有单相，双相和三相，即PPA510，PPA520和PPA530. PPA500系列属于入门级简易型功率分析仪，通俗简称功率计。
2. PPA1500系列有单相，双相和三相，即PPA1510，PPA1520和PPA1530. PPA1500系列在PPA500系列的基础上频宽更宽，另外自带示波器显示功能，属于功能强大，基本满足全部工业应用领域产线测试需求。
3. PPA3500系列有单相，双相，三相，四相，五相和六相， 即PPA3510，PPA3520，PPA3530，PPA3540，PPA3550和PPA3560六个型号和规格。PPA3500系列具有双核处理器，能最大限度的提升功率分析仪自身的测试分析能力，具有业界体积最小，2U标准高度，应用最广，便于客户集成测试需要.
4. PPA4500系列有单相，双相和三相， 即PPA4510，PPA4520和PPA4530.
5. PPA5500系列有单相，双相和三相，即PPA5510，PPA5520和PPA5530.

Newtons4th Ltd (abbreviated to N4L) was established in 1997 to design, manufacture and support innovative electronic equipment to a world-wide market.

Specialising in sophisticated test equipment for the power electronics industry including Power Analyzers, Frequency Response Analyzers(gain/phase analyzers), AC Power Sources, Impedance Analyzers and Selective Level Meters.

Newtons4th Ltd (abbreviated to N4L) was established in 1997 to design, manufacture and support innovative electronic test instrumentation to a world-wide market. Specialising in sophisticated test equipment, particularly related to phase measurement, our product portfolio includes Power Analyzers, Frequency Response Analyzers (gain/phase analyzers), Impedance Analyzers, Vector Voltmeters, Phase Meters, true RMS voltmeters, Selective Level Meters and Laboratory Power Amplifiers. The company was founded on the principle of using latest technology and sophisticated analysis techniques in order to provide our customers with accurate, easy to use instruments at a lower price than has been traditionally associated with these types of measurements. Flexibility in our products and an attitude to providing the solutions that our customers really want has allowed us to develop many innovative functions in our ever increasing product range. In early 2015, N4L relocated to a state of the art manufacturing facility situated close to Leicester City Centre, England. The new site covers over 2,040 m² (22,050 ft²) and features a purpose built “clean” manufacturing environment with environmental control.

The name Newton (Sir Isaac) is synonymous with a thorough understanding of physical principles from observation of the real world. His well known 3 laws of motion are so simple and clear that they are easily learned and applied, yet they give us the tools to analyse the motion of very complex systems. The number 4 represents innovation, building on what is already established. Newtons4th – innovation based on established fundamental principles.

Newtons4th Ltd are ISO9001 registered, the internationally recognised standard for the quality management of businesses. In recognition of the technical innovation and commercial success of the PPA series, N4L received the “Innovation 2010″ Queen’s award.