是德科技
直播中

宋阳

8年用户 144经验值
私信 关注
[问答]

错误报告：34465A/34470A数字万用表的CAL/ACAL例程出错

嗨，我上周拿到了全新的34465A数字万用表，它已经由Keysight（初始/生产校准）6月1日校准。
开箱即用，它有一个令人不安的高校准计数222.另一个新的34470A的所有者发现76卡路里计数，似乎也太高，可能高达20或40似乎是合理的，因为计数似乎增加了
仅每个校准组1个。
（100V和500V DCV的校准仅增加1）我认为，是德科技目前在生产过程中最终校准这些仪器存在很大问题。
我发现，使用ACAL后，DCV范围为100mV，1V和+/- 10V，并且始终为10GOhm。
如果我切换到10MOhm，两个范围内的读数都会高出+ 3ppm，尽管不涉及硬件切换，因为HV范围已经处于10MOhm模式！
如果我使用10MOhm设置进行校准，则验证也会失败+ 3ppm，切换到AUTO会消除此错误。
这两个误差总计达到+17和+ 20ppm，这已经是90天的漂移。
在Keysight校准过程中，由于ACAL可能在验证之前启用，这可能会导致校准错误，解释我的仪器的高222计数。
其次，如果仪器已经以20ppm开始并且正常漂移将增加，那么该仪器将在90天或1年规格中失效。
因此，我需要Keysight工程部门的支持，以获得对该错误的确认，以及固件或硬件中的修复，如果它证明与HW相关（我的理解可能性较小）。
我还可以提供序列号，测试报告以及我自己测量的更多细节。
关心弗兰克博士

以上来自于谷歌翻译


     以下为原文

  Hi,
I got my brand new 34465A DMM last week, it had been calibrated by Keysight (initial/ production calibration) June 1st.

Out of the box, it had a disturbingly high calibration count of 222.

Another owner of a new 34470A found 76 cal counts, which seems also too high, maybe up to 20 or 40 seems to be reasonable, as the count seems to increase by 1 per calibration group only. (calibraton of 100V and 500V DCV increases by 1 only)

I assume, Keysight currently has big problems to finally calibrate these instruments in their production run.

I found out, that the DCV ranges 100mV, 1V, and +/- 10V were spot on, after using ACAL, always 10GOhm).
If I switch to 10MOhm, the reading is +3ppm higher in both ranges, although there is no hardware switching involved, as the HV ranges are already in this 10MOhm mode!

If I calibrate with 10MOhm setting, the verification also fails by +3ppm, switching to AUTO removes this error.

Both errors sum up to +17 and +20ppm, which already is the 90 day drift.

During Keysights calibration process, as ACAL probably is engaged before verification, that will probably cause a calibration error, explaining the high 222 counts of my instrument.

Secondly, this instrument will fail the 90 days or 1 year specification, if it already starts at 20ppm and the normal drifts will add to that.

So I need support from Keysight engineering, to get a confirmation of that bug, and a fix in the firmware, or in hardware, if it turns out to be HW related (less probable to my understanding).
I could also supply serial number, test report and further details of my own measurements.

Regards

Dr. Frank  

回帖（7）

杨秀英

2018-10-10 17:48:51
Keysight对此错误有任何反馈意见吗？

以上来自于谷歌翻译


     以下为原文

  Is there any feedback from Keysight regarding this bug?
举报

宋阳

2018-10-10 18:07:06
引用: 罕井雅直 发表于 2018-10-10 19:29
Keysight对此错误有任何反馈意见吗？

以上来自于谷歌翻译

您好，是的，是德科技很快就做出了反应。
他们给我发了一个新乐器，而“旧”乐器现在正在前往马来西亚进行分析。
他们已经确认了其他仪器上的+ 3ppm偏移，但是尝试将其他故障分配给热效应（通过1000V负载）。
我想，我已经破坏了他们的论点，所以他们应该进一步调查。
我的新款34465A仅有76卡路里计数，如果是新鲜工厂，这是默认计数。
当然它也有+ 3ppm的误差，相对于3周的校准/验证，100V范围也显示+ 10 .. + 14ppm的偏移，而100mV，1和10V的范围，再次点亮，
即偏差我不想再通过重新校准100V和1kV范围再次确认此校准故障，到目前为止。
所以我真的有越来越多的证据，ACAL的校准转换也是一个真正的固件问题。
最后，我对Keysight的支持和努力非常满意！
坦率

以上来自于谷歌翻译


     以下为原文

  Hello,

yes, Keysight very quickly reacted.

They've sent me a new instrument, and the "old" one is now on its way to Malaysia, to be analysed.

They already confirmed the +3ppm shift on other instruments, but try to assign the other fault to thermal effects (by 1000V burden).
I think, I already have busted their argument, so they should investigate further.

My new 34465A has 76 cal counts only, and this is the default count if being fresh from the factory.

Of course it has this +3ppm error also, and the 100V range also shows + 10..+ 14ppm shift relative to its 3 weeks old calibration / validation, compared to the 100mV, 1 and 10V ranges, which were again spot-on, i.e. deviation < 1ppm (+ thermal offset in the 100mV range). 
I did not want to confirm this calibration fault again, by re-calibration of the 100V and 1kV ranges, up to now.

So I really have more and more proof, that also the calibration shift by ACAL is a real firmware issue.

In the end, I am very satisfied with the support and effort by Keysight!

Frank
举报

杨秀英

2018-10-10 18:25:47
引用: qwe043 发表于 2018-10-10 19:47
您好，是的，是德科技很快就做出了反应。
他们给我发了一个新乐器，而“旧”乐器现在正在前往马来西亚进行分析。
他们已经确认了其他仪器上的+ 3ppm偏移，但是尝试将其他故障分配给热效应（通过1000V负载）。

嗨，非常感谢您的反馈。
我的新款34465A的计数为82，非常新鲜。
我买了这个DMM，因为它的准确性（与价格相关......）是德科技的声誉。
所以，我希望他们尽快解决这个问题（并且不需要重新校准......）。
再次感谢。

以上来自于谷歌翻译


     以下为原文

  Hi,

thank you very  much for your feedback.

My new 34465A has a cal count of 82, obvoiusly fresh from the factory.

I bought this DMM because of it's accuracy (in relation to the price...) an Keysight's reputation.

So, i hope they will fix this bug asap (and no recalibration is necessary...).

Thanks again.
举报

宋阳

2018-10-10 18:37:44
引用: 罕井雅直 发表于 2018-10-10 20:06
嗨，非常感谢您的反馈。
我的新款34465A的计数为82，非常新鲜。
我买了这个DMM，因为它的准确性（与价格相关......）是德科技的声誉。

您也可以检查3ppm的错误..只需在100V范围内施加10V ...... 100V的稳定电压。
参与统计，因此7位数将显示为平均值。
当您在10M和AUTO之间切换阻抗时，该值应该更改该数量（始终清除统计数据）如果您的仪器是全新的，意味着校准仅在几周前，您还可以检查其他可能的错误：
在10V范围内施加稳定的10V并测量其精确值，为6或7位数（带统计数据）。
现在切换到100V，阻抗AUTO，并使用统计/平均值将此相同值测量为6位分辨率。
由于A / D转换器与典型的10V线性相关，100V应该已经过验证，这意味着，10：1比率（10V范围与100V范围）最初也精确到约1ppm。
如果你发现一个更大的偏差，这是一个提示，（没有确定的证据！）你的仪器也会出现这个错误。
坦率

以上来自于谷歌翻译


     以下为原文

  You may check the 3ppm bug also.. simply apply a stable voltage of 10V...100V in the 100V range.
Engage statistics, so 7 digits will be displayed as average.
When you toggle the impedance between 10M and AUTO, the value should change by that amount (always clear statistics)

If your instrument is brand new, meaning that the calibration is only a few weeks ago, you may also check for the other possible error:
Apply a stable 10V in the 10V range and measure its precise value, to 6 or 7 digits (with statistics).
Now switch to 100V, impedance AUTO, and measure this same value to 6 digits resolution, using statistics/average.
As the A/D converter is linear to typical < 1ppm, a possible deviation of 10ppm should be easily detectable.

10V and 100V should have been validated to <= 1ppm deviation, as documented in your calibration test report.
That means, the 10:1 ratio (10V range vs. 100V range) is also precise to about 1ppm, initially. 

If you find a bigger deviation, that's a hint, (no certain proof!) that your instrument also got this error.

Frank
举报

更多回帖

7 0 0

相关问答

数字万用表
发帖
电子发烧友APP
|投诉反馈|电子发烧友网
© 2021 bbs.elecfans.com
湘ICP备2023018690号
×
20
完善资料，
赚取积分