芯耀
110
在电力电子、电机驱动、开关电源及工业控制系统的研发与调试中，经常需要对非地参考的高压信号（如半桥中点、三相桥臂电压）进行安全、精确的测量。是德科技（Keysight，前身安捷伦Agilent）N2795A高压差分探头专为此类应用而设计，以其高共模抑制比、宽带宽和安全的CAT II等级，成为工程师进行高压浮地信号测量的可靠工具。
为确保此类关键测量附件长期保持准确的性能和安全的操作状态，定期的功能验证与维护十分必要。深圳市宝安区沙井方丰瑞仪器设备经营部在测试测量附件及系统服务领域具备专业能力，可为N2795A用户提供专业的技术支持与服务保障。
N2795A：高压浮地测量的安全桥梁
核心性能与技术特点：
提供 CAT II 600 V、CAT I 1000 V 的安全等级，能够安全地测量对地存在高共模电压的差分信号。
最大差分电压 ±1400 V（DC+峰值AC），满足多数中高压电路的测试需求。
优异的测量精度与带宽
带宽高达 200 MHz，能够准确捕获高速开关波形（如IGBT、MOSFET的开关瞬态）。
高共模抑制比（CMRR）：在直流至1 MHz范围内 > 80 dB，在10 MHz时 > 60 dB，有效抑制共模噪声，确保差分测量的准确性。
输入阻抗高（差分：4 MΩ || 3 pF），对被测电路影响极小。
灵活的衰减比与偏置调节
提供 25:1 和 250:1 两种衰减比（通过探头主体切换），适应不同的电压测量范围。
内置 可调直流偏置 功能，便于观察叠加在高压直流上的小幅度交流纹波。
探头尖端配备 可更换的弹簧挂钩和绝缘夹，便于连接不同封装尺寸的测试点。
便捷的自动识别与补偿
支持是德科技 AutoProbe 接口（适用于兼容的示波器），可自动识别探头类型和衰减比，并设置示波器垂直量程。
需要配合示波器的 探头方波输出 进行幅频和直流平衡补偿，以获得最佳测量精度。
典型应用场景
开关电源与逆变器测试：测量半桥、全桥电路的中点电压，分析死区时间、驱动波形。
电机驱动器调试：测量三相电机的相电压、线电压，分析PWM调制波形。
工业设备故障诊断：安全测量变频器、UPS等设备中的高压浮地信号。
电力电子研发：用于SiC、GaN等宽禁带器件的高速开关特性评估。
专业服务保障测量安全与精度
高压差分探头的性能会随着使用时间、环境（如温度、湿度）以及可能的意外过载而发生变化。其衰减比精度、带宽、共模抑制比和补偿状态都需要定期验证，以确保测量数据准确且操作安全。
深圳市宝安区沙井方丰瑞仪器设备经营部在此领域能够为用户提供关键支持：
综合性能校准与验证：使用专业校准源，对探头的衰减比精度、带宽、上升时间、共模抑制比（CMRR） 等关键参数进行校准与验证。
直流平衡与补偿调整：检查并调整探头的直流平衡，确保在不同衰减比下的测量准确性。
安全性与绝缘测试：检查探头线缆、BNC接头及前端附件的绝缘性能和物理完整性，确保其符合标称的安全等级。
附件检查与更换：检查探头挂钩、绝缘夹等附件是否完好，并提供更换服务。
故障诊断与维修：对无信号、精度超差、补偿失效、线缆破损等故障进行专业诊断与维修。
结语
是德科技N2795A高压差分探头以其安全的设计、优异的性能和便捷的自动识别功能，为工程师安全、精确地观测高压浮地信号提供了理想的解决方案。它是进行现代电力电子和工业控制系统调试不可或缺的“眼睛”。
确保这双观察高压世界的“眼睛”始终清晰、准确且安全，离不开专业的校准与维护。通过与 深圳市宝安区沙井方丰瑞仪器设备经营部 这样的专业服务伙伴合作，用户可以确保其N2795A探头及其他关键测试附件始终处于最佳工作状态，从而在高压测试中既能获得可靠的数据，又能保障人员和设备的安全。
Keysight N2795A High-Voltage Differential Probe: A Safe Bridge for High-Voltage Floating Measurements
In the research, development, and debugging of power electronics, motor drives, switching power supplies, and industrial control systems, there is often a need to safely and accurately measure high-voltage signals that are not referenced to ground (e.g., half-bridge midpoints, three-phase bridge leg voltages). The Keysight (formerly Agilent) N2795A High-Voltage Differential Probe is specifically designed for such applications. With its high common-mode rejection ratio (CMRR), wide bandwidth, and safe CAT II rating, it serves as a reliable tool for engineers measuring high-voltage floating signals.
To ensure that such critical measurement accessories maintain accurate performance and safe operating conditions over the long term, regular functional verification and maintenance are essential. The Shenzhen Bao'an District Shajing Fangfengrui Instrument Equipment Business Department possesses professional expertise in test measurement accessories and system services, offering specialized technical support and service assurance for N2795A users.
N2795A: A Safe Bridge for High-Voltage Floating Measurements
Core Performance and Technical Features:
Safe Electrical Isolation and High Voltage Rating:
Provides a safety rating of CAT II 600 V, CAT I 1000 V, enabling safe measurement of differential signals with high common-mode voltages relative to ground.
Maximum differential voltage: ±1400 V (DC + peak AC), meeting the testing needs of most medium- and high-voltage circuits.
Isolates from the oscilloscope via an optical cable, protecting both the operator and the oscilloscope.
Excellent Measurement Accuracy and Bandwidth:
Bandwidth up to 200 MHz, accurately capturing high-speed switching waveforms (e.g., switching transients of IGBTs and MOSFETs).
High common-mode rejection ratio (CMRR): > 80 dB from DC to 1 MHz, > 60 dB at 10 MHz, effectively suppressing common-mode noise and ensuring accurate differential measurements.
High input impedance (differential: 4 MΩ || 3 pF), minimizing impact on the device under test.
Flexible Attenuation Ratios and Offset Adjustment:
Provides two attenuation ratios (25:1 and 250:1, switchable on the probe body) to accommodate different voltage measurement ranges.
Built-in adjustable DC offset function facilitates observation of small AC ripple superimposed on high DC voltages.
Probe tip includes replaceable spring hooks and insulated clips for easy connection to test points of varying package sizes.
Convenient Automatic Recognition and Compensation:
Supports the Keysight AutoProbe interface (for compatible oscilloscopes), automatically recognizing probe type and attenuation ratio and setting the oscilloscope vertical scale accordingly.
Requires compensation using the oscilloscope’s probe square wave output for optimal amplitude-frequency and DC balance accuracy.
Typical Application Scenarios:
Switching Power Supply and Inverter Testing: Measuring midpoint voltages in half-bridge and full-bridge circuits, analyzing dead time and drive waveforms.
Motor Drive Debugging: Measuring phase and line voltages of three-phase motors, analyzing PWM modulation waveforms.
Industrial Equipment Fault Diagnosis: Safely measuring high-voltage floating signals in devices such as frequency converters and UPS systems.
Power Electronics R&D: Evaluating high-speed switching characteristics of wide-bandgap devices like SiC and GaN.
Professional Services Ensure Measurement Safety and Accuracy:
The performance of high-voltage differential probes can degrade over time due to usage, environmental factors (e.g., temperature, humidity), and potential accidental overloads. Regular verification of attenuation ratio accuracy, bandwidth, CMRR, and compensation status is essential to ensure accurate measurement data and operational safety.
The Shenzhen Bao'an District Shajing Fangfengrui Instrument Equipment Business Department provides critical support in this area:
Comprehensive Performance Calibration and Verification: Using professional calibration sources to calibrate and verify key probe parameters such as attenuation ratio accuracy, bandwidth, rise time, and common-mode rejection ratio (CMRR).
DC Balance and Compensation Adjustment: Inspecting and adjusting the probe's DC balance to ensure measurement accuracy across different attenuation ratios.
Safety and Insulation Testing: Checking the insulation performance and physical integrity of probe cables, BNC connectors, and front-end accessories to ensure compliance with the rated safety standards.
Accessory Inspection and Replacement: Inspecting the condition of probe hooks, insulated clips, and other accessories, and providing replacement services as needed.
Fault Diagnosis and Repair: Professional diagnosis and repair of issues such as no signal, out-of-spec accuracy, compensation failure, and cable damage.
Conclusion
The Keysight N2795A High-Voltage Differential Probe, with its safe design, excellent performance, and convenient automatic recognition features, provides an ideal solution for engineers to safely and accurately observe high-voltage floating signals. It is an indispensable "eye" for debugging modern power electronics and industrial control systems.
Ensuring that these "eyes" observing the high-voltage world remain clear, accurate, and safe requires professional calibration and maintenance. By partnering with a professional service provider like the Shenzhen Bao'an District Shajing Fangfengrui Instrument Equipment Business Department, users can ensure that their N2795A probes and other critical test accessories are always in optimal working condition. This guarantees reliable data acquisition and safeguards both personnel and equipment during high-voltage testing.
