EEVblog Electronics Community Forum
EEVblog => Other Blogs => Topic started by: Hugoneus on March 23, 2015, 03:05:19 pm
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Hi everyone,
This is a full review of the Keithley 2460. I already have done the review of the 2450 and this episode features a whole new set of experiments as well as a teardown of the unit. I hope you like it.
Watch the video here: [1 Hour & 5 Minutes]
http://youtu.be/zT80zDZgOWU (http://youtu.be/zT80zDZgOWU)
More videos at The Signal Path:
http://www.TheSignalPath.com (http://www.TheSignalPath.com)
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We don't like it, we Love it ! O0
Do you happen to have teardown photos? Can you post those , just in case? I do like look into Keithley gear inside.
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We don't like it, we Love it ! O0
Do you happen to have teardown photos? Can you post those , just in case? I do like look into Keithley gear inside.
Great!
I did not take any photos yet. I'll try to take some and post it.
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Wonderful review video, thanks so much.
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Wonderful review video, thanks so much.
You are welcome.
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Nice video, however: you've been very, very mild to Keithley!
At 11:15 you compare the 2450 with the 2460 against the reference. The 2460 is spot on, but the 2450 is 10 counts off!
But because it is Keithley, you say: "is all accurate and I have no doubt .."
I find 10 count difference between 2 instruments at the same temperature and accuracy rather much.
I wonder what you would have said if it was a unknown brand, or a Chinese one? A bit more critical look perhaps?
note: same applies to the fan, position and noise. Again very mild about this.
I wonder if its a Keithley sponsored video?
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Nice video, however: you've been very, very mild to Keithley!
At 11:15 you compare the 2450 with the 2460 against the reference. The 2460 is spot on, but the 2450 is 10 counts off!
But because it is Keithley, you say: "is all accurate and I have no doubt .."
I find 10 count difference between 2 instruments at the same temperature and accuracy rather much.
I wonder what you would have said if it was a unknown brand, or a Chinese one? A bit more critical look perhaps?
note: same applies to the fan, position and noise. Again very mild about this.
I wonder if its a Keithley sponsored video?
No the video is not sponsored by anyone. None of my videos are sponsored.
The specified range accuracy of these units is +/- 0.015% rdg + 1mV. These measurements are well within the specified calibration limits. These units have also been calibrated 8 months apart. Furthermore, yes, I trust Keithley because they have earned it.
I mention the fan noise of the 2460 several times throughout the video. I also mention that for me personally the fan noise compromise to get the unit in the same form factor is worth it. This is the only statement I make in the whole video which is a personal preference.
I would have said the exact same thing if it was a Chinese brand. Watch my Rigol video reviews, they are Chinese. If it is an unknown brand (Chinese or not) I would spend more time verifying the claimed specification. For that see my Analog Arts USB scope review.
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Wow, I'm glad I don't make youtube videos. Every time someone says something good about something, they're accused of taking a bribe; and if they say something bad they're a biased hater. Often both at once.
Thank you, Shahriar, for putting up with the bullshit and continuing to make interesting videos.
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Wow, I'm glad I don't make youtube videos. Every time someone says something good about something, they're accused of taking a bribe; and if they say something bad they're a biased hater. Often both at once.
Thank you, Shahriar, for putting up with the bullshit and continuing to make interesting videos.
Thank you. I really don't have any issue with criticism. I welcome it! Without any criticism how could I ever improve my work or find mistakes? I just hope that the discussions are always based on evidence and reason.
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For comparison, it would be nice to see a teardown of the 2450 too!
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Nice video, however: you've been very, very mild to Keithley!
At 11:15 you compare the 2450 with the 2460 against the reference. The 2460 is spot on, but the 2450 is 10 counts off!
But because it is Keithley, you say: "is all accurate and I have no doubt .."
I find 10 count difference between 2 instruments at the same temperature and accuracy rather much.
I wonder what you would have said if it was a unknown brand, or a Chinese one? A bit more critical look perhaps?
note: same applies to the fan, position and noise. Again very mild about this.
I wonder if its a Keithley sponsored video?
I think we have established quite authoritatively that Shahriar is not biased and has no vested interest whatsoever in being less than objective. Listen to the amp hour episode with Shahriar, and you will learn about his background and qualifications. He has much better things to do than create and share these videos, and we collectively are quite privileged that he takes the time to do so.
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Another great video. I really enjoy the combination of new equipment with the experiments. That takes a lot of work and planning and as a regular viewer of your videos I very much appreciate the effort. Great work.
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Shahriar:
I always enjoy your reviews and other videos. They always bring more to the table than just "look at this box". They are very educational as well as being a thorough review.
Please take the next comment as constructive criticism. The color balance of your videos is always way off and very distracting to me, personally. It may just be me but others might see it the same way. Adjusting your color balance is a necessary thing for video if you want high quality production. In many cameras it is an easy function to find in a menu. If you can find it, just find something in the lab that is what looks like neutral grey to you and make sure it fills the frame and then set your white balance. This is not perfect but should make a huge difference in the appearance of your videos. There are white balance cards available in almost every camera shop that will will do it better if you are so inclined.
Again, thanks for your videos. I always watch them to the end and always learn something.
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Nice video, however: you've been very, very mild to Keithley!
At 11:15 you compare the 2450 with the 2460 against the reference. The 2460 is spot on, but the 2450 is 10 counts off!
But because it is Keithley, you say: "is all accurate and I have no doubt .."
I find 10 count difference between 2 instruments at the same temperature and accuracy rather much.
I wonder what you would have said if it was a unknown brand, or a Chinese one? A bit more critical look perhaps?
note: same applies to the fan, position and noise. Again very mild about this.
I wonder if its a Keithley sponsored video?
I am sure you must be mistaken. In this video:
https://www.youtube.com/watch?v=3EjmCWmarwE#ws (https://www.youtube.com/watch?v=3EjmCWmarwE#ws)
he uses a Chinese 6 1/2 digit bench meter to probe some 5/15 volt internal supply voltages in a HP-box. The meter gets a very positive report.
I use a 10 dollar handheld for "OK or Faulty" probing of internal supplies, but that is another question.
[Edit - grammar and shortened]
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I obviously stepped on some soles here and there. Wow.
@quantumvolt: no, I quote from the video. I mentioned even the exact moment, 11:15
@Shahriar: So you actually own a 2450 AND a 2460 unit?
Just to be clear, I liked the video very much.
But there is nothing wrong when reviewing gear to be critical on the review, despite the brand or origin. Every reporter/journalist has to ask the right questions, to get the most of it.
I remember Dave say that he has terms and conditions on how he does his reviews. If I remember correctly, LeCroy wanted to donate some stuff for review, but took a hike when they heard about his terms.
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I obviously stepped on some soles here and there. Wow.
@quantumvolt: no, I quote from the video. I mentioned even the exact moment, 11:15
@Shahriar: So you actually own a 2450 AND a 2460 unit?
Just to be clear, I liked the video very much.
But there is nothing wrong when reviewing gear to be critical on the review, despite the brand or origin. Every reporter/journalist has to ask the right questions, to get the most of it.
I remember Dave say that he has terms and conditions on how he does his reviews. If I remember correctly, LeCroy wanted to donate some stuff for review, but took a hike when they heard about his terms.
I don't think Shahriar's integrity is in question - check out his USB scope review to see him call things out (quite rightly too)
https://www.youtube.com/watch?v=F-1uA4Iwce8 (https://www.youtube.com/watch?v=F-1uA4Iwce8)
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I obviously stepped on some soles here and there. Wow.
I appreciate everyone's comments and I appreciate that no one is being hostile as there is no need for it.
@quantumvolt: no, I quote from the video. I mentioned even the exact moment, 11:15
I addressed this already. Both units are well within specification, they have also been calibrated many months apart. They show a difference of 90uV on a 20V range. How did you want me to criticize this? Would it not have been unscientific and unprofessional for me to criticize an instrument which is well within its specifications? I also mention in the video that I verified all other parameters and they too were in spec. I didn't record that because it would have been a waste of people's time.
@Shahriar: So you actually own a 2450 AND a 2460 unit?
That is not really relevant here because you have to show me where I have played favoritism here.
- I showed the very difficult test of an unstable fan which produced spikes and caused the instrument to supply a different voltage than what was shown on the screen. As a result of my test and criticism Keithley may add a whole new feature to their product line.
- I showed the plotting mistakes the instrument sometimes makes. Again, I have reported this to Keithley. I had also reported a series of issues to Keithley before which they addressed in a firmware already.
- I mentioned the fan's loudness several times.
Just to be clear, I liked the video very much.
Thank you! O0
But there is nothing wrong when reviewing gear to be critical on the review, despite the brand or origin. Every reporter/journalist has to ask the right questions, to get the most of it.
And I was critical as I mentioned above.
I remember Dave say that he has terms and conditions on how he does his reviews. If I remember correctly, LeCroy wanted to donate some stuff for review, but took a hike when they heard about his terms.
No one has ever given me terms and conditions for my reviews. If anyone ever does, that unit will not get reviewed by me.
As I said before, I have no problem with your criticism and I welcome them. But you have to give me something that I can actually work with.
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@Shahriar: So you actually own a 2450 AND a 2460 unit?
That is not really relevant here because you have to show me where I have played favoritism here.
May I conclude that you NOT own the units, and that they were given to you to review?
I think it is better to give full disclosure about those things, it helps to put things into perspective.
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@Shahriar: So you actually own a 2450 AND a 2460 unit?
That is not really relevant here because you have to show me where I have played favoritism here.
May I conclude that you NOT own the units, and that they were given to you to review?
Of course, this is public knowledge. Sometimes the units are loaners and they have to go back and sometimes I can hold onto them for future videos. At other times I have purchased the instrument myself. None of this is relevant because it has no impact on my review.
I think it is better to give full disclosure about those things, it helps to put things into perspective.
Helps put what into perspective? You are willfully making unwarranted extrapolations that because instrument X was given to me, instrument X received a positive review. This is actually quiet insulting to me as a scientist and considering the amount of effort that goes into making a review such as the ones that I do.
Do you have an example where I have played favoritism of the instrument or not? I am interested in improving the videos. Provide an example and I will be happy to change my approach.
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Helps put what into perspective? You are willfully making unwarranted extrapolations that because instrument X was given to me, instrument X received a positive review. This is actually quiet insulting to me as a scientist and considering the amount of effort that goes into making a review such as the ones that I do.
I have no intentions to insult you, and I apologize if I did.
Do you have an example where I have played favoritism of the instrument or not? I am interested in improving the videos. Provide an example and I will be happy to change my approach.
In my first posting I mentioned the part at 11:15, and quoted your comment.
Your answer was: "Furthermore, yes, I trust Keithley because they have earned it.
I find that very mild towards Keithley. Why is the first unit spot on with the reference and the second unit more then 10 counts off? Yes, they are in spec, but I would expect them closer together. Certainly for what the instruments pretend to be.
My 34401A's are always within 1 count with each other, and I know from a other forum member that his 34401A's and 34470A are also within one count.
I am not a fanboy of any kind, just being critical on what I get told. I guess that came with my education.
But don't let me stop you making video's. I know that it takes a lot of time, and a lot of people are enjoying it very much.
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I have no intentions to insult you, and I apologize if I did.
Thank you. I too am sorry if I came across frustrated.
I find that very mild towards Keithley. Why is the first unit spot on with the reference and the second unit more then 10 counts off? Yes, they are in spec, but I would expect them closer together. Certainly for what the instruments pretend to be.
My 34401A's are always within 1 count with each other, and I know from a other forum member that his 34401A's and 34470A are also within one count.
The 2450 and 2460 are rather different internally as a result of their power handling capability. When I had a loaner 2450, I compared two 2450's together and they were 1 or 2 parts apart also. I don't think it is reasonable to expect two rather different instruments to be less than 2 counts apart.
I am not a fanboy of any kind, just being critical on what I get told. I guess that came with my education.
Good qualities which are required for critical thinking. I appreciate that.
But don't let me stop you making video's. I know that it takes a lot of time, and a lot of people are enjoying it very much.
As long as I am able to make videos, I will make them. Creation and dissemination of knowledge is a fundamental human responsibility.
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The whole review bias issue is overblown in general. A good review reveals absence of bias. This 2460 review/experiments video is a great example. We see what the instrument can do. We see it in operation: fan noise, graphing oddity, and all of the great stuff too. As a result we have much more knowledge of the instrument. At the same time we get to learn something from the experiments themselves. I purchased a 2450 after a lot of research and probably would not have acquired such an expensive instrument without the level of detail shown in Shahriar's 2450 video. On the other hand, I have no need for the 2460. The fan would drive me crazy, and I don't presently need the broader current range it offers. I really hope Keithley is giving him these instruments to keep. His review / experiments videos are more than worth it.
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Back on topic...
What I would really like to see from Keithley is a one quadrant version of the 2460 (hopefully resulting in losing that fan noise). An update of the 2280S-32-6 with TSP link and the new touch screen for under $2000 (better, under $1500) would be perfect. So much of the power of these instruments comes from the scripting capability over multiple devices. Many uses only require operation limited to +V +I ranges. A DMM7510 (or 2450 or both) TSP-linked to such an updated power supply would be terrific.
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An update of the 2280S-32-6 with TSP link and the new touch screen for under $2000 (better, under $1500) would be perfect.
They made two mistakes with the 2280S series, 1. not using their touchscreen UI, 2. no sense terminals on the front. They created a winner UI with the 2450, they should use it on all their products from now on.
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An update of the 2280S-32-6 with TSP link and the new touch screen for under $2000 (better, under $1500) would be perfect.
They made two mistakes with the 2280S series, 1. not using their touchscreen UI, 2. no sense terminals on the front. They created a winner UI with the 2450, they should use it on all their products from now on.
Yes, I agree with you on this. They probably wanted to keep the cost down, and I am also not sure if the GUI and new touch-screen interface was ready when the 2280S was introduced.
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Are the touchscreens on these devices capacitive or resistive? Hard to tell from the videos if the touch/drag system lags the processor or is just a result of a non-responsive touchscreen.
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I just looked up the 2280S and it is $ 2500 on ebay! What is so special about it to have such a price tag?
The screen looks similar to the 2450 SMU
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I just looked up the 2280S and it is $ 2500 on ebay! What is so special about it to have such a price tag?
The screen looks similar to the 2450 SMU
It is a very low-noise and high-precision power supply up to 192W. It can also measure down to 100nA with 6.5 digits of precision. It is almost like a SMU in one quadrant only and much higher power. It also has programmable rise/fall times.
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I just looked up the 2280S and it is $ 2500 on ebay! What is so special about it to have such a price tag?
The screen looks similar to the 2450 SMU
The 2280S-32-6 is $1,990 at Newark. Everything about it (at least from the specs) is terrific but it lacks TSP-Link. I could live without the touch interface (though it should have it, and I agree that front sense ports would be very helpful as well), but it really needs the TSP-Link interface.
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I got a 2460 but am not that impressed. The AUTO current range does not cover the full source range.
I.e. select source 1A, measure Auto or 1A and you risk getting overflow. The measure function cannot handle even 0.1% over range and the calibration of the unit is not that good:
(http://lygte-info.dk/pic/cpf2/DSC_9770.jpg)
And according to Keithley that is acceptable behaviour.
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HKJ,
Want to unload that 2460 since you're not impressed with it? I would love to have a 2460.
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Want to unload that 2460 since you're not impressed with it? I would love to have a 2460.
Not really, I paid a bit above $8000 for it and hope to get some usage out of it, but the precision will be rather bad for the price.
With a limit of 100mA and measuring range of 1A (Next higher range) I get 100.2mA (With a specific setup), i.e. 0.2% error.
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I.e. select source 1A, measure Auto or 1A and you risk getting overflow. The measure function cannot handle even 0.1% over range and the calibration of the unit is not that good:
The unit is supposed to do that. It has a hard limit on the "limit" you set. That is what it is supposed to do.
Not really, I paid a bit above $8000 for it and hope to get some usage out of it, but the precision will be rather bad for the price.
With a limit of 100mA and measuring range of 1A (Next higher range) I get 100.2mA (With a specific setup), i.e. 0.2% error.
I am very surprised about that. I did a test on my unit. As you can see in the picture the error (compared to a new 7.5 digit meter) is less than 0.0174%. I suspect something might be wrong with your setup. I hope you can resolve the issue.
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I am very surprised about that. I did a test on my unit. As you can see in the picture the error (compared to a new 7.5 digit meter) is less than 0.0174%. I suspect something might be wrong with your setup. I hope you can resolve the issue.
Are those the same cables? The ground cable banana jack has a different color end...even the cable looks a shade of blue next to the black cabling on top.
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I am very surprised about that. I did a test on my unit. As you can see in the picture the error (compared to a new 7.5 digit meter) is less than 0.0174%. I suspect something might be wrong with your setup. I hope you can resolve the issue.
Are those the same cables? The ground cable banana jack has a different color end...even the cable looks a shade of blue next to the black cabling on top.
The red cable goes from the SMU to the DMM. The black cable goes from the SMU to a resistor and the blue cable is the return from the resistor to the DMM. That is how the circuit is closed.
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I.e. select source 1A, measure Auto or 1A and you risk getting overflow. The measure function cannot handle even 0.1% over range and the calibration of the unit is not that good:
The unit is supposed to do that. It has a hard limit on the "limit" you set. That is what it is supposed to do.
As usual a limit has some tolerance and in some cases a 1A limit can deliver slightly above 1A, but it is silly that the meter goes into overflow because of that, a included 1% over range in the measurement circuits would have avoided any problems like that.
As it is now the auto range function does always work.
Not really, I paid a bit above $8000 for it and hope to get some usage out of it, but the precision will be rather bad for the price.
With a limit of 100mA and measuring range of 1A (Next higher range) I get 100.2mA (With a specific setup), i.e. 0.2% error.
I am very surprised about that. I did a test on my unit. As you can see in the picture the error (compared to a new 7.5 digit meter) is less than 0.0174%. I suspect something might be wrong with your setup. I hope you can resolve the issue.
It is probably the measurement function that is a bit out, it is only using 10% of its range, this means offset errors are more significant.
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As usual a limit has some tolerance and in some cases a 1A limit can deliver slightly above 1A, but it is silly that the meter goes into overflow because of that, a included 1% over range in the measurement circuits would have avoided any problems like that.
In the brochure, they specify "OVERRANGE: 105% of range, source and measure."
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In the brochure, they specify "OVERRANGE: 105% of range, source and measure."
This is not present in my 2460.
Limit 0.9999 measures 0.9999
Limit 0.99997 measures 0.99995
Limit 0.99998 measures overflow
Limit 0.99999 measures overflow
This is with the source=4 volt, another source value will give different results.
I am running software version 1.1.0c
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The new firmware version for the 2460 fixes this problem.
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The new firmware version for the 2460 fixes this problem.
Thanks for letting us know about the new FW
Downloading it now.