Keysight 16048A是世界上最无用的配件吗？

自动平衡桥接仪器通常配备有BNC连接器并采用4端子对配置。
用于连接LCR仪表的延长电缆的终端连接器必须采用4端子对配置，以实现宽阻抗测量范围和精确测量。
选择合适的测试夹具和电缆以及获得最佳DUT连接配置的技术对于最大化总测量精度非常重要。
有关各种端子配置的优点的更多详细信息，请参阅“阻抗测量手册”的第3章。
http://literature.cdn.keysight.com/litweb/pdf/5950-3000.pdf 16048A测试引线采用4端子对配置。
它扩展了测量端口，允许连接用户制造的测试夹具。
如果客户想要制造自己的测试引线，建议使用同轴电缆，如图3-11所示，阻抗测量手册第3-11页：http：//literature.cdn.keysight.com/litweb
/pdf/5950-3000.pdf 16048x测试引线旨在为Keysight四端子对LCR仪表和阻抗分析仪提供最佳结果。
我们保证了我们测试的指定配置的准确性。
这些是我们为产品支持16048A的主要原因。
请注意，电缆长度校正功能仅适用于是德科技指定的4端子对测试引线/固定装置。
此功能不适用于非Keysight测试引线，如普通BNC电缆和用户自制的测试引线。
Keysight四端子对LCR仪表和阻抗分析仪具有出厂时记忆的电缆长度校正数据，性能测试验证了0 m / 1m / 2 m / 4 m电缆长度的测量精度。
即使相应的测试引线/夹具未连接到LCR仪表或阻抗分析仪，也会执行CABLE长度设置的CABLE长度校正计算。
CABLE长度校正功能设置与实际使用的测试引线/夹具之间不匹配可能会导致额外的测量误差。



     以下为原文

  An auto-balancing bridge instrument is generally equipped with BNC connectors and employing 4-Terminal Pair configuration. The terminal connector of the extension cable which is used to connect to the LCR meter has to be in 4-Terminal Pair configuration for wide impedance measurement range and accurate measurements. 
The selection of appropriate test fixtures and cables as well as the techniques for obtaining the optimum DUT connection configuration are important for maximizing the total measurement accuracy. Please refer to chapter 3 of the Impedance Measurement Handbook for more detail about the benefits of various terminal configurations.  
http://literature.cdn.keysight.com/litweb/pdf/5950-3000.pdf

16048A test lead employs the 4-Terminal Pair configuration. It extends the measurement port and allows the attachment of user-fabricated test fixtures. 
If the customer would like to fabricate own test lead, it is recommended to employ the coaxial cable as shown in Figure 3-11 on page 3-11 Of the Impedance Measurement Handbook: http://literature.cdn.keysight.com/litweb/pdf/5950-3000.pdf

The 16048x test leads are designed to provide the best result for Keysight four-terminal pair LCR meters and impedance analyzers. We guarantee the accuracy with specified configuration we tested. These are the main reasons we support the 16048A for our product. 

Please take note that the cable length correction function is valid for Keysight-specified 4-Terminal Pair test leads/ fixtures only. This function cannot be applied to non-Keysight test leads such as ordinary BNC cable and user-fabricated test lead. The Keysight four-terminal pair LCR meters and impedance analyzers have the cable length correction data memorized at factory, and the measurement accuracy for 0 m/ 1m/ 2 m/ 4 m cable length is verified by the performance tests. The CABLE length correction calculation for the CABLE length setting is carried out even if the appropriate test leads/fixture is not connected to the LCR meter or impedance analyzer. A mismatch between the CABLE length correction function setting and the actual test leads/fixture used may cause additional measurement errors.

> {quote：title = YeeChuang写道：} {quote}您好，非常感谢您回复并解释此目的。
但我仍然不明白为什么其中一些特征是至关重要的，这显然是由于我缺乏理解。
> 16048A测试引线采用4端子对配置。
它扩展了测量端口，允许连接用户制造的测试夹具。
>如果客户想要制造自己的测试引线，建议使用同轴电缆，如图3-11所示，阻抗测量手册第3-11页：http：//literature.cdn.keysight.com/
litweb / pdf / 5950-3000.pdf但为什么电缆会扭曲？
我理解开尔文设置的基本概念，其中两个引线将电流传递到DUT，另外两个测量DUT上的电压，但是如图3-11所示扭转同轴电缆的目的是什么？
电缆是同轴的，以及电缆中包含的磁场，这让我想知道扭曲电缆的目的是什么。
（作为一名射频工程师，我倾向于尽可能少地弯曲电缆，而不是像图表那样扭曲它们）。
>请注意，电缆长度校正功能仅适用于是德科技指定的4端子对测试引线/固定装置。
此功能不适用于非Keysight测试引线，如普通BNC电缆和用户自制的测试引线。
Keysight四端子对LCR仪表和阻抗分析仪具有出厂时记忆的电缆长度校正数据，性能测试验证了0 m / 1m / 2 m / 4 m电缆长度的测量精度。
即使相应的测试引线/夹具未连接到LCR仪表或阻抗分析仪，也会执行CABLE长度设置的CABLE长度校正计算。
CABLE长度校正功能设置与实际使用的测试引线/夹具之间不匹配可能会导致额外的测量误差。
为什么电缆长度很重要？
如果电缆长度不正确，我看到第4.5.2节给出了误差的等式误差（％）= k * delta_L * f ^ 2其中k在-1到1的范围内，delta_L以米为单位，f in
兆赫。
我不知道我的4284A上有什么“k”，但是最差情况值为1，然后在1 MHz时，电缆长度的100 mm误差可能会产生0.1％的误差，这是基本不确定度的两倍。
4284A（0.05％）。
所以似乎电缆长度相当重要，但我不明白为什么。
您知道4284A上的选项006（2米和4米电缆长度）是硬件选项，还是软件选项？
非常感谢您的宝贵时间。
戴夫



     以下为原文

  > {quote:title=YeeChuang wrote:}{quote}

Hello Yee, 
Thank you very much for replying and explaining the purpose of this. But I still do not understand why some of the characteristics of that are critical, which is clearly due to my lack of understanding. 

> 16048A test lead employs the 4-Terminal Pair configuration. It extends the measurement port and allows the attachment of user-fabricated test fixtures. 
> If the customer would like to fabricate own test lead, it is recommended to employ the coaxial cable as shown in Figure 3-11 on page 3-11 Of the Impedance Measurement Handbook: http://literature.cdn.keysight.com/litweb/pdf/5950-3000.pdf

But why are the cables twisted? 

I understand the basic concept of the Kelvin setup, where two leads pass current into a DUT, and another two measure the voltage across the DUT, but what is the purpose of twisting the coaxial cables as in figure 3-11? The fact the cables are coaxial, and the fields contained within the cables, makes me wonder what the purpose of twisting the cables is. (As an RF engineer, I tend to flex cables as little as possible, not twist them like that diagram shows). 

> Please take note that the cable length correction function is valid for Keysight-specified 4-Terminal Pair test leads/ fixtures only. This function cannot be applied to non-Keysight test leads such as ordinary BNC cable and user-fabricated test lead. The Keysight four-terminal pair LCR meters and impedance analyzers have the cable length correction data memorized at factory, and the measurement accuracy for 0 m/ 1m/ 2 m/ 4 m cable length is verified by the performance tests. The CABLE length correction calculation for the CABLE length setting is carried out even if the appropriate test leads/fixture is not connected to the LCR meter or impedance analyzer. A mismatch between the CABLE length correction function setting and the actual test leads/fixture used may cause additional measurement errors.

Why is cable length critical? I see section 4.5.2 gives an equation for the error if the cable length is not correct

Error (%) = k * delta_L * f^2
where k is in the range -1 to 1, delta_L is in metres, and f in MHz. 

I've no idea what "k" is on my 4284A, but taking a worst case value of 1, then at 1 MHz, a 100 mm error in cable length could produce an error of 0.1%, which is twice the basic uncertainty of the 4284A (0.05%). So it seems that the cable lengths is fairly critical, but I don't understand why. 

Do you know if option 006 (2 m and 4 m cable lengths) on the 4284A are hardware options, but software ones? 

Thank you very much for your time. 

Dave

>但为什么电缆会扭曲？
没有必要扭曲4TP配置的电缆。
该图只是电缆8121-1218的图像。
它有四根同轴电缆。
>为什么电缆长度很重要？
（在没有端接的电缆延伸的情况下）桥接不平衡和4TP电缆延伸的阻抗测量结果的误差仅在高频（通常高于100kHz）时是关键的。
在图4-12中，Zhg表示由Hcur和Hpot测试电缆的电容确定的阻抗。
该阻抗在高频下降低。
并且该阻抗会降低测试信号电平并降低测量精度。
Zlg表示由Lcur和Lpot测试电缆的电容确定的阻抗。
在高频时该阻抗也减小。
并且该阻抗降低了放大器的输入阻抗并导致测量不准确。
因此，与Keysight提供的电缆的电缆长度差异可能会产生阻抗测量误差。
在这种情况下，开路/短路/负载补偿可用于减少测量误差。
>您知道4284A上的选项006（2m和4m电缆长度）是硬件选项，还是软件选项？
选项006不添加其硬件，但需要选项006的调整和性能测试。
但是，4284A超出了它的支持寿命。
是德科技服务中心将尽其所能为其提供支持。
如果您想添加选项006或校准其4284A，请联系Keysight服务中心。



     以下为原文

  >But why are the cables twisted?
It is not necessary to twist the cables for the 4TP configuration. The diagram is just a image for the cable 8121-1218. It has four coaxial cables.


>Why is cable length critical? (in case of cable extension without termination)
The bridge unbalance and the error in impedance measurement results by 4TP cable extension are critical only at high frequencies (typically above 100kHz).
In Figure 4-12, Zhg means an impedance determined by the capacitance of the Hcur and Hpot test cables. This impedance  is decreased at high frequencies. And this impedance decreases test signal level and degrades measurement accuracy. 
Zlg means an impedance determined by the capacitance of the Lcur and Lpot test cables. This impedance is also decreased at high frequencies. And this impedance decreases input impedance of the amplifier and results measurement inaccuracy.
Therefore, the cable length difference from the Keysight-supplied cables may produce an impedance measurement error.
In this case, the open/short/load compensation can be used to reduce the measurement error.


>Do you know if option 006 (2m and 4m cable lengths) on the 4284A are hardware options, but software ones?
The option 006 does not add its hardware, but the adjustment and performance test for the option 006 are required.
However, the 4284A is beyond its support life. Keysight service center will do the best they can to support it. 
If you want to add option 006 or calibrate their 4284A, please contact Keysight service center.

> {quote：title = YeeChuang写道：} {quote} >>但是为什么电缆会扭曲？
>没有必要扭曲4TP配置的电缆。
该图只是电缆8121-1218的图像。
它有四根同轴电缆。
谢谢。
我认为扭转同轴电缆是不寻常的，但图表显然欺骗了我。
>>为什么电缆长度很重要？
（如果电缆延伸没有端接）>电桥不平衡和4TP电缆延长的阻抗测量结果误差仅在高频（通常高于100kHz）时才是关键。
>在图4-12中，Zhg表示由Hcur和Hpot测试电缆的电容确定的阻抗。
该阻抗在高频下降低。
并且该阻抗会降低测试信号电平并降低测量精度。
> Zlg表示由Lcur和Lpot测试电缆的电容确定的阻抗。
在高频时该阻抗也减小。
并且该阻抗降低了放大器的输入阻抗并导致测量不准确。
>因此，与Keysight提供的电缆的电缆长度差异可能会产生阻抗测量误差。
>在这种情况下，开路/短路/负载补偿可用于减少测量误差。
谢谢。
>>>你知道4284A上的选项006（2m和4m电缆长度）是硬件选项，还是软件选项？
>选项006不添加其硬件，但需要选项006的调整和性能测试。
>但是，4284A超出了它的支持寿命。
是德科技服务中心将尽其所能为其提供支持。
>如果您想添加选项006或校准其4284A，请联系Keysight服务中心。
谢谢你。
如果可能的话，我会期待添加选项006。
我打算在大约一个月后将仪器送到Keysight进行校准 - 在我收到我订购的16047A灯具后。
我可以问你关于选件4284A-004存储卡的相同问题。
那是软件还是硬件？
如果它是软件，那么也许可以升级。
我会问，但是知道它是软件还是硬件升级会很好。
非常感谢您的帮助。
戴夫



     以下为原文

  > {quote:title=YeeChuang wrote:}{quote}
> >But why are the cables twisted?
> It is not necessary to twist the cables for the 4TP configuration. The diagram is just a image for the cable 8121-1218. It has four coaxial cables.

Thank you. I thought it unusual to twist coaxial cables, but the diagram was obviously deceiving me. 

> >Why is cable length critical? (in case of cable extension without termination)
> The bridge unbalance and the error in impedance measurement results by 4TP cable extension are critical only at high frequencies (typically above 100kHz).
> In Figure 4-12, Zhg means an impedance determined by the capacitance of the Hcur and Hpot test cables. This impedance  is decreased at high frequencies. And this impedance decreases test signal level and degrades measurement accuracy. 
> Zlg means an impedance determined by the capacitance of the Lcur and Lpot test cables. This impedance is also decreased at high frequencies. And this impedance decreases input impedance of the amplifier and results measurement inaccuracy.
> Therefore, the cable length difference from the Keysight-supplied cables may produce an impedance measurement error.
> In this case, the open/short/load compensation can be used to reduce the measurement error.

Thank you. 

> >Do you know if option 006 (2m and 4m cable lengths) on the 4284A are hardware options, but software ones?
> The option 006 does not add its hardware, but the adjustment and performance test for the option 006 are required.
> However, the 4284A is beyond its support life. Keysight service center will do the best they can to support it. 
> If you want to add option 006 or calibrate their 4284A, please contact Keysight service center.

Thank you for that. I will look to get option 006 added if possible. I intend sending the instrument to Keysight for calibration in about a month - after I receive my 16047A fixture, which I have on order.  

Can I ask you the same question about option 4284A-004 Memory card. Is that software or hardware? If it is software, then maybe that could be upgraded. I will ask, but it would be good to know if its a software or hardware upgrade. 

Thank you very much for your help. 

Dave

4284A-004存储卡是硬件选项。
正如您所知，4284A已经停产，不再受支持。
因此，此选项的升级也不再可用。



     以下为原文

  4284A-004 memory card is a hardware option. As you have already known, 4284A is already discontinued and no longer supported. Therefore the upgrade of this option is no longer available too.