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Measuring at the LOWER END of a range is not good to see if the entire range is OK, they should be checking at both the bottom end and upper end to check linearity, if it is reading out by 0.0085V at 30V, at 200V it will could be out by 0.0566V.
The calibration procedures for these are done at 0V and +- 200mV, 2V, 20V, 200V, 1000V (the centre and ends of each range).
BUT it is good to see that Siglent are going to be replacing your unit, I am sure they just had to be sure first that there really was a problem. -
Good news
Ours is due tomorrow
Best,
Cool, let us know how ya like it. -
Arrived a coupled hours ago. Got it setup and running now for quick evaluation, in parallel with KS33465A, Agilent 34401A & HP 34401A. Using a 10V Source from a LM399 that been aging for ~year, or a LTZ1000 that's been running for a ~month. Also have some other references, one is based on an LM399 (aged over a year) that give 10, 1 and 0.1V outputs. I'll work on this later, in the middle of some other things at the moment.
Seems the SDM3065X was factory calibrated 2/2020
So 1 1/2 year old calibration, had asked for the latest available, but Saelig said this was the last one they had.
It's now showing ~80uv above the other 3 DMMs at 10V. One thing I did notice it fired up and displayed ~70uv high initially, then settled into 80uv for the past hour, so little drift from the initial startup.
I haven't even read the manual yet, and don't know if it has a built-in cal capability, so don't take this as any anything other than it appress to be working OK.
Best,
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Better Image
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Right when the world ground to snails pace and shipping took so much longer and port clearance too.
Seems the SDM3065X was factory calibrated 2/2020
How it ages against your references will be interesting if you can take the trouble to make a few notes following it.
Drop me mail about adjustments if you think you need it.
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Better Image
You definitely don't have enough test gear.
Not nearly enough for what I'm doing
Need to monitor and display 128 analog channels from the device we are developing, which can produce up to +-75V independent outputs with 15 bit precision. It's like a HV 15 bit 128 output AWG, the outputs must be perfectly balanced in that if one phase is +68.657 volts, the next phase must be -68.657 volts within a couple millivolts as the output waveform bi-phase toggles back and forth. The slew rates must also match to this level. The waveforms are created from high resolution DACs, then bi-phase modulated and amplified up to the +-75V levels.
Needed variable supplies that's precise and stable, and with low noise voltages outputs with precise low level current limits. Selected 3 of SPD3303X. These produce +-7V, +-60V, +5V, +3.3V, another supply provides +5.5V and two precison voltage reference sources provide 2.500V and 0~10V variable. If we need the supplies for the higher ranges then a couple switch mode 120V supplies are used, but these produce some switching noise which masks getting very accurate measurements, so only used when the highest output voltage are required. The SPD3303X are very quiet and stable supplies, really like them
A custom low noise SMPS design is underway to supply all the required voltages. Eventually this may lead to a custom chip design.
Thinking about displaying 16 channels simultaneously, could use ADC and such, but would need 16 input stages (they need to be very low capacitance, like one gets with a quality scope probe), high impedance, variable voltage ranges, and such. 8 Channels scopes seem expensive, so maybe using 4 4 channel DSOs synched up, but that's down the road some, no time for this now.
Anyway, the SDM3065X seems stable at 80uv high on 10V compared to the other DMMs.
SD is showing 2uv for 35K samples
Now back to design work
Best,
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Right when the world ground to snails pace and shipping took so much longer and port clearance too.
Seems the SDM3065X was factory calibrated 2/2020
How it ages against your references will be interesting if you can take the trouble to make a few notes following it.
Drop me mail about adjustments if you think you need it.
I suspected so, lucky we got the last one Saelig had in stock
The parts supply shortage is wreaking havoc with the design process. I've had to redesign things so many times, just for the available parts, only to find that they evaporated
Now we've gone to a mode if we think a component will be useful we buy them right away then start designing around them. If the design seems OK, then design the PCBs
Yeah, probably should start a log on the SDM3065X. Maybe give it a few weeks to settle in, it's rock steady at 10.00008 volts now. The AC is cycling ON/OFF and air blows right over my bench setup, so not exactly a thermally stable environment.
Best, -
Better Image
You definitely don't have enough test gear.
Not nearly enough for what I'm doing
Need to monitor and display 128 analog channels from the device we are developing, which can produce up to +-75V independent outputs with 15 bit precision. It's like a HV 15 bit 128 output AWG, the outputs must be perfectly balanced in that if one phase is +68.657 volts, the next phase must be -68.657 volts within a couple millivolts as the output waveform bi-phase toggles back and forth. The slew rates must also match to this level. The waveforms are created from high resolution DACs, then bi-phase modulated and amplified up to the +-75V levels.
Needed variable supplies that's precise and stable, and with low noise voltages outputs with precise low level current limits. Selected 3 of SPD3303X. These produce +-7V, +-60V, +5V, +3.3V, another supply provides +5.5V and two precison voltage reference sources provide 2.500V and 0~10V variable. If we need the supplies for the higher ranges then a couple switch mode 120V supplies are used, but these produce some switching noise which masks getting very accurate measurements, so only used when the highest output voltage are required. The SPD3303X are very quiet and stable supplies, really like them
A custom low noise SMPS design is underway to supply all the required voltages. Eventually this may lead to a custom chip design.
Thinking about displaying 16 channels simultaneously, could use ADC and such, but would need 16 input stages (they need to be very low capacitance, like one gets with a quality scope probe), high impedance, variable voltage ranges, and such. 8 Channels scopes seem expensive, so maybe using 4 4 channel DSOs synched up, but that's down the road some, no time for this now.
Anyway, the SDM3065X seems stable at 80uv high on 10V compared to the other DMMs.
SD is showing 2uv for 35K samples
Now back to design work
Best,
So with that "long" calibration, it differs 8-9 ppm from Keysights. An has 0.2 ppm RMS noise. That is not bad at all.
LM399 probably didn't move much at all since cal, because they practically don't drift when off.
But I know you'll be keeping the records
so let us know how it moves with time.
Take care.
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All the references are powered all the time, except during a power outage. So these have a number of "burn-in" hours on them
Still at 80uv high and stable!!!
Best, -
If there will be drift on meter, first 3 months will be the most, than after 6 months it will settle to tempco level variations and hard to keep track of.....
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If there will be drift on meter, first 3 months will be the most, than after 6 months it will settle to tempco level variations and hard to keep track of.....
Thought you were talking about the LM399 in our references, not the DMM.
My bad
Best, -
Replacement Scheduled for delivery tomorrow last Scan was Chicago.
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We haven't seen much drift since this new SDM3065A arrived last Saturday. Started out with about ~80uV high, last couple days moved up to ~100uV high relative to KS34465A and a pair of Agilent & HP 344041As monitoring a 10 volt reference.
Hopefully your new DMM will be as good or better
Best, -
Receive a package today, it seems like they ship old stock.
Per Siglent Site: https://int.siglent.com/account.php?module=warranties
The one I sent in had a Warranty expire date of 01/22/2024
The Replacement has a Warranty Date of 10/28/2023
I know I am splitting hairs here but time is time! Right now will keep it boxed up!
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Receive a package today, it seems like they ship old stock.
It doesn't surprise me that SiglentNA would have slightly older stock then Amazon. The have to travel by boat, so those units may have arrived more recently than you think given the state of global shipping lately. Anyhow, I'm pretty sure they start the warranty from the purchase date and those dates are just there as the default if you don't have the receipt. You can clarify with SiglentNA, but I'm pretty sure your warranty and cal are OK and you should just unbox it. -
Wow, you have more will-power than I do
I couldn't wait to get the SDM unpacked, hooked up and running
If you decide to open the box and check, please report the cal date certificate.
BTW, agree with bdunham7, think the warranty starts running from the time of purchase/receipt, and should not be any less than this. Your new SDM should be warrantied for the span of the original SDM I believe.
Best, -
Receive a package today, it seems like they ship old stock.
Splitting entirely the wrong hairs too !
Per Siglent Site: https://int.siglent.com/account.php?module=warranties
The one I sent in had a Warranty expire date of 01/22/2024
The Replacement has a Warranty Date of 10/28/2023
I know I am splitting hairs here but time is time! Right now will keep it boxed up!
Siglent's factory warranty conditions DONT apply in the US. Period !
Where instead US warranty is from proven date of sale.
https://siglentna.com/service-and-support/warranty-information/
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Right now I am disappointed.. my thoughts have been confirmed!
Really want to open it but have to hold off! More info soon!
Maybe Tonight, Tomorrow, Next Week / Month? I will fill ya in just waiting for the conclusion!
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Right now I am disappointed.. my thoughts have been confirmed!
Really want to open it but have to hold off! More info soon!
What thoughts, what confirmed? Is receiving replacement meter which was produced less than 3 months earlier (and that does not affect actual warranty) something worth to fuss about?QuoteMaybe Tonight, Tomorrow, Next Week / Month? I will fill ya in just waiting for the conclusion!
As if it can be something worthwhile. -
I have very little trust these days with company's especially with ones as young as singlet and the prior customer service I received. The first after sale service interactions crossed off to many of the never do or say to a customer items fermenting the distrust.
What I did not mention publicly was that the box had already been opened and resealed! I was Awaiting the Reply from Siglent which I receive this morning.
On the call this morning From David.
He explained they only have "old stock" they all have expired cal-certs after 6 mo on the shelf and they have to open them and check the calibration on them prior to shipping reason the 1 week lead time. He understood my concerns of an open box (I was worried I receive B stock or another customer return). He told me that all they did is check calibration units was not a return / refurbished etc. (He understood my concern about the calibration procedure and explanation on the returned one) He wrote me an e-mail reassuring me if I am not happy (even being old stock) just use it and they would replace with an unopened current stock when it arrives. That was good enough for me!
Have a Coffee or two!! Grab the blade and carefully open the box. There is an envelope containing a Cal Cert Dated 08/05/21 Scott Rocco
I fire up the PSU and the DC Load and Let it warm up! Plug in the 3065X power it up let it burn in a bit go about my day.
Many Hours Later!
I hook up the Fluke, DC Load, and 3065X In Parallel and Proceeded to check volts up and down. See if they Agree!!
Side Note: The Siglent PSU is 3.5 years old and was calibrated using the procedures in the SPD3303 service manual with a friends Keysight EDU34450A. I hope I can talk him in to bring it back down with him one day.
The big moment do they agree after a few hours? I checked 1v to 60V. Here is 25V!
Fluke and SDM3065X
Siglent DC Load a Little disagreement but acceptable. (Leads are shorter to the DC Load)
So Why is it that this 3065X agree's with the PSU, Fluke, and DC Load and the other one did not? This one seems to be stable also after a few hours will keep it on for (week) 168 hours and recheck.
David is very reasonable person and listens to logic. If you ever need assistance from Siglent talk to David. Scott in my opinion needs a big lesson in customer service (pink slip type) I have other words I could use but will not express them publicly.
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So Why is it that this 3065X agree's with the PSU, Fluke, and DC Load and the other one did not? This one seems to be stable also after a few hours will keep it on for (week) 168 hours and recheck.
Obviously the other one was broken. It would be interesting to figure out what the exact issue was with it, but I guess we'll be deprived of that particular learning experience. At first glance it might appear to be a tempco issue, but I actually think it is more likely to be an issue with some sort of tempco compensation scheme and related stored values, as Kleinstein suggested earlier. I think a the undocumented (publicly at least) nature of many modern instruments is a huge drawback. We aren't likely to ever know exactly how this system works.QuoteDavid is very reasonable person and listens to logic. If you ever need assistance from Siglent talk to David. Scott in my opinion need a lesson big in customer service (pink slip type) I have other words I could use but will not express them publicly.
Frustration at this sort of debacle is understandable, but I'm jaded enough to actually prefer an honest but wrong opinion to carefully rehearsed PR bullshit. The tech in question tried an experiment to try and confirm or refute your assertion of a defect, apparently got the concepts wrong and I suppose things went downhill from there. Perhaps he felt strongly that he was right--it's not uncommon for support people to think that their customers are idiots because often times they are. That's why I predicted that things might get ugly--and I'm glad to hear that everything was quickly resolved, although not perhaps at a technical level or for technical reasons.
And for those that doubted the F187, don't ever bet against ancient Fluke or HP meters, even if they have tire tracks on them.
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Yea, for-sure something was not working right with that other unit.
The mathematical dribble Scott spewed trying to justify the error.
It would be nice to know why Serial # SDM36GBQ4R0577 was that far off and drifted with time. I was going to post the SN earlier then deleted. I figure the SN should be public just in case it's resold as a factory second / refurbished unit and someone has the same issues with it they may find this post.
Quickly? that is subjective.. It Seemed like forever!
My fluke is a Fricken reliable tank very few issue the last 20 years. It sat in a drawer for a good 12-13years being used off and on while I ventured in my Aviation Career traveling this planet solo never knowing what county I would end up in next!
I plan on grabbing a Fluke 287 soon and pass this 187 down to the kid I's sure it's got another decade of life left in it.
I will put it thru its paces.. I got a few Venkel Engineering sample kits with hundreds of values of caps and resistors. So far this dmm seems faster at resolving the values! -
Yea, for-sure something was not working right with that other unit.
The mathematical dribble Scott spewed trying to justify the error.
It would be nice to know why Serial # SDM36GBQ4R0577 was that far off and drifted with time. I was going to post the SN earlier then deleted. I figure the SN should be public just in case it's resold as a factory second / refurbished unit and someone has the same issues with it they may find this post.
Quickly? that is subjective.. It Seemed like forever!
My fluke is a Fricken reliable tank very few issue the last 20 years. It sat in a drawer for a good 12-13years being used off and on while I ventured in my Aviation Career traveling this planet solo never knowing what county I would end up in next!
I plan on grabbing a Fluke 287 soon and pass this 187 down to the kid I's sure it's got another decade of life left in it.
I will put it thru its paces.. I got a few Venkel Engineering sample kits with hundreds of values of caps and resistors. So far this dmm seems faster at resolving the values!
Glad to hear you got it sorted out, nothing worse when you get new equipment and it doesnt work as described.
BTW, there are many in these forums which very much like the 187/189 meters. I have both the 189 and 287 (both of which I got very good deals on), but the one that usually sits on the bench is the 189 mainly because it starts up quicker. Be interesting to see which you prefer after you start using the 287. -
It has powered on over 24 hours stable so far.
I have some Venkel Capacitor and Resistor engineering kits I was testing some values today and it seems to be accurate.