sanwa is a very accurate meter when you know how to use it, it would smoke even the expensive digital ones especially on measuring resistance,finding leaks and even detecting pcb moisture
You really messed up by NOT zeroing the meter using the zero adjust pot when measuring each resistor. You have to do this every time you change magnitude of your resistance. You will not be accurate unless you do this procedure before measuring resistors.
if first scale was let's say zeroed, it showed 1k, then moving the scale, it showed 900 ohms which is 10% not accurate, so he should've thought why is that, because that multimeter is not that much wrong. Of course you need to do zeroing for each magnitude/scale.
That’s what happens when you’re not used to analog multimeters... As it has been said before, you have to zero the meter in by shorting the leads, before you make any kind of measurement.
Excelente el protector p el SANWA preg donde lo compraste y una preg más con ese multimetro análogo SANWA se pueden medir pulsos automotrices d sensores actuadores y válvulas d transmisión automática electrónica pregunto gracias por orientación ayuda
The black case was purchased from the store in Akihabara, it was about 1500 yen from memory. overseas.sanwa-meter.co.jp/products/accessory-fuse/c_ca.html
My dad used to use an analogue insulation tester on fault finding for similar reason to you. Was easier to see a needle moving across the display than having to look for a number on an lcd display
So he was using a megger to trace faults in a circuit board? That’s interesting. I’ve actually seen other people do this, obviously must be a bit complicated because if you just hooked it straight up… It would pretty much blow everything I think. I think it can also be used to test capacitor leakage in some cases if you have a dropping resistor. But I’m not really sure how that would work. I use power supplies all the time to find bad components. When quickly diagnosing a fault, I start with my FLIR thermal camera, but if that doesn’t work… I use a current limited supply with a resistor in series. So that I can push a low-voltage and controlled current through the board, and look for the heated traces or other signs of fault.. Most commonly shorts or heat… which has caused or is generating internal board faults, component faults, heatsink bonding faults, current overload faults, or even shorted faults hidden beneath multi pin components due to solder balls etc. Probing around all those small parts for faults can be very tedious. But with the constant current supply… I can quickly probe around and look for the lowest dropped voltage… Usually a pretty fast process but the flir thermal camera is always my first choice! Sorry didn’t mean to ramble, I’d be interested to hear how your dad used the insulation tester to find faults. analog meters are so important, most people don’t know how useful they really are! can easily see what’s going on in real time instead of super fast updates, with numbers flashing and speeding by on the new digital meters
Is normal practice in the electrical industry to use them on circuits that have potential wiring or equipment faults. They arent used on electronic equipment. Most experienced electricians know not to connect to live supplies that will potentially damage themselves and the equipment. They are never used on sensitive equipment only on circuit wiring and appliances that cant be damaged. On most mains powered equipment faults it isnt safe to start putting power in to the circuit. As may risk fires and potential other issues. They are never used on circuit boards on insulation resistance voltage. Finally the Megger name is a brand name that seems to be used on any insulation resistance tester.
Edit: I was a bit quick on my previous reply and put my foot firmly in my mouth :P In this case, for voltage, the specification does say a +/- 3% of full scale on the DCV range. So the most accuracy is near the top end of the range. That means only the last division is within 3%, it actually gets WORSE the lower you go, reducing to 3.75% at around 80% of the scale, 5% at 60% of scale, 6% at 50% of the scale, 7.5% at 40% of the scale, ballooning to 15% at 20% of the scale, 30% at 10% of scale. As the pointer approaches zero, the meter error is constant but the percentage of error increases until the over-all error reaches and exceeds 100 percent at the very low end. An example for your DC reading on the 30V DC scale, if you are measuring 15V (verified by some other source) the meter could read anywhere from 14.1V to 15.9V and be within spec. I'd recommend checking out the PDF I linked to below for more about it. For resistance, however, they give a specification of +/- 3% of arc which means the arc on the range selected. If you want to know how to read the resistance properly, check out this old Electronics World magazine from 1966. It shows how to read the resistance properly for different types of meters. On the magazine scan it'll be page 82, but it's page 78 of the actual PDF. worldradiohistory.com/Archive-Electronics-World/60s/1966/Electronics-World-1966-04.pdf
@@redemptusrenatus5336For what it's worth, the movement in this meter is *way* more accurate than the FS error specs indicate. The one I got is well within +/-0.5% on the movement linearity. It was hard measuring it to begin with - had to use machine vision to read out the pointer angle. The analog front-end could be made to match the movement if one wanted to. The FET front-end is probably where a lot of the error originates from. A jellybean CMOS op-amp should take care of that - even the lousiest op-amp is more linear than the movement. If someone wanted to design an alternate PCB for that thing, it could be a pretty good upgrade. With a good nanovoltmeter front end it's possible to use the taut band as a torsion strain gage, although that's of academic interest mostly. It requires resolution and stability that costs so much you could just slap a resolver in there and have a meter with a mechanical accuracy good enough to read out with a loupe :)
Of course it would be trivial to reset the Ohms calibration to improve that accuracy. It seems that the voltage dividers are almost perfect (very uniform between ranges) so just a small tweak of that trimpot! As an aside, it would be an improvement to swap out those horrid little trimpots for a set of multi-turn wirewound pots. Make the setting easier plus more stable than the carbon pots over time.
I could do a trimpot swap, but then I'm up against the inaccuracy of reading an analogue gauge anyway. I've swapped trimpots out on other gear before for the exact reasons you mention (like my Yokogawa 2554 volt/current standard I made a previous video on), but I don't think the improvement in accuracy would have much effect when the display isn't digital. Plus it is still under warranty, so it'll have to wait before I start modding it anyway. :D
Do you know why these multimeter has ohms adjuster ? And you can't get real time needle movement because it has fet across it. It delays You can compare under $50 analog meter's needle moving speed with this one. This multimeter use for mesasurement not for fault findings like DMMs and diagnose
@@NearFarMedia Two things, I have something to send to you for review and perhaps use. Just a little electronic project. Not so soon as the current situation not okay yet. The other thing, I wish to communicate through email. my email is yusdiytechATgmaildotcom
Hello. I have 2 of them. One is damaged due to a leak of the 9v battery. Trimpots went damaged. The other one keeps stored without the batteries. Other than that fragility, they are wonderful. Good price for a FET input Multimeter.
Ohhh, AND, just one final thing, the SANWA user manual ..specifically warns you ..NOT, to ..Change ..Ranges, on the meter, WHILE, it is ..connected to ANY energised circuit..!! 🙄🙄
They did it wrong. Using a chopper amplifier is way more advantagous than using a FET differential amplifier. There is a circuit for the similar EM3000 on the internet.
Before measure the resistence you need to "zero" the multimeter scale.
sanwa is a very accurate meter when you know how to use it, it would smoke even the expensive digital ones especially on measuring resistance,finding leaks and even detecting pcb moisture
19:36 you not ADJ the ZERO before measuring the Ohms for sure
You really messed up by NOT zeroing the meter using the zero adjust pot when measuring each resistor. You have to do this every time you change magnitude of your resistance. You will not be accurate unless you do this procedure before measuring resistors.
if first scale was let's say zeroed, it showed 1k, then moving the scale, it showed 900 ohms which is 10% not accurate, so he should've thought why is that, because that multimeter is not that much wrong. Of course you need to do zeroing for each magnitude/scale.
That’s what happens when you’re not used to analog multimeters... As it has been said before, you have to zero the meter in by shorting the leads, before you make any kind of measurement.
Excelente el protector p el SANWA preg donde lo compraste y una preg más con ese multimetro análogo SANWA se pueden medir pulsos automotrices d sensores actuadores y válvulas d transmisión automática electrónica pregunto gracias por orientación ayuda
Thank you for your review..I have the same meter but where did you buy the Black case and how much is it?
The black case was purchased from the store in Akihabara, it was about 1500 yen from memory.
overseas.sanwa-meter.co.jp/products/accessory-fuse/c_ca.html
How is about it schematic diagram ?
For each Resistance Range scale , you would need to Re-Zero that scale. Otherwise happens exactly the “inaccuracies” you witnessed.
My dad used to use an analogue insulation tester on fault finding for similar reason to you. Was easier to see a needle moving across the display than having to look for a number on an lcd display
So he was using a megger to trace faults in a circuit board? That’s interesting.
I’ve actually seen other people do this, obviously must be a bit complicated because if you just hooked it straight up… It would pretty much blow everything I think. I think it can also be used to test capacitor leakage in some cases if you have a dropping resistor.
But I’m not really sure how that would work. I use power supplies all the time to find bad components.
When quickly diagnosing a fault, I start with my FLIR thermal camera, but if that doesn’t work…
I use a current limited supply with a resistor in series. So that I can push a low-voltage and controlled current through the board, and look for the heated traces or other signs of fault..
Most commonly shorts or heat… which has caused or is generating internal board faults, component faults, heatsink bonding faults, current overload faults, or even shorted faults hidden beneath multi pin components due to solder balls etc.
Probing around all those small parts for faults can be very tedious. But with the constant current supply… I can quickly probe around and look for the lowest dropped voltage… Usually a pretty fast process but the flir thermal camera is always my first choice!
Sorry didn’t mean to ramble,
I’d be interested to hear how your dad used the insulation tester to find faults.
analog meters are so important, most people don’t know how useful they really are!
can easily see what’s going on in real time instead of super fast updates, with numbers flashing and speeding by on the new digital meters
Is normal practice in the electrical industry to use them on circuits that have potential wiring or equipment faults. They arent used on electronic equipment. Most experienced electricians know not to connect to live supplies that will potentially damage themselves and the equipment. They are never used on sensitive equipment only on circuit wiring and appliances that cant be damaged. On most mains powered equipment faults it isnt safe to start putting power in to the circuit. As may risk fires and potential other issues. They are never used on circuit boards on insulation resistance voltage. Finally the Megger name is a brand name that seems to be used on any insulation resistance tester.
DC voltage readings on mine are always like 0.5 V off (lower) in 30 V scale. Should I mess with the internal pot or just consider is within spec?
Edit: I was a bit quick on my previous reply and put my foot firmly in my mouth :P In this case, for voltage, the specification does say a +/- 3% of full scale on the DCV range. So the most accuracy is near the top end of the range. That means only the last division is within 3%, it actually gets WORSE the lower you go, reducing to 3.75% at around 80% of the scale, 5% at 60% of scale, 6% at 50% of the scale, 7.5% at 40% of the scale, ballooning to 15% at 20% of the scale, 30% at 10% of scale. As the pointer approaches zero, the meter error is constant but the percentage of error increases until the over-all error reaches and exceeds 100 percent at the very low end. An example for your DC reading on the 30V DC scale, if you are measuring 15V (verified by some other source) the meter could read anywhere from 14.1V to 15.9V and be within spec. I'd recommend checking out the PDF I linked to below for more about it. For resistance, however, they give a specification of +/- 3% of arc which means the arc on the range selected. If you want to know how to read the resistance properly, check out this old Electronics World magazine from 1966. It shows how to read the resistance properly for different types of meters. On the magazine scan it'll be page 82, but it's page 78 of the actual PDF. worldradiohistory.com/Archive-Electronics-World/60s/1966/Electronics-World-1966-04.pdf
@@redemptusrenatus5336For what it's worth, the movement in this meter is *way* more accurate than the FS error specs indicate. The one I got is well within +/-0.5% on the movement linearity. It was hard measuring it to begin with - had to use machine vision to read out the pointer angle. The analog front-end could be made to match the movement if one wanted to. The FET front-end is probably where a lot of the error originates from. A jellybean CMOS op-amp should take care of that - even the lousiest op-amp is more linear than the movement. If someone wanted to design an alternate PCB for that thing, it could be a pretty good upgrade. With a good nanovoltmeter front end it's possible to use the taut band as a torsion strain gage, although that's of academic interest mostly. It requires resolution and stability that costs so much you could just slap a resolver in there and have a meter with a mechanical accuracy good enough to read out with a loupe :)
Is there any circuit diagram
Nothing from the manufacturer unfortunately.
ISO 9001 is a manufacturing tracing system, it does not guarantee accuracy, only traceability.
Ah yep, you are correct. :)
Of course it would be trivial to reset the Ohms calibration to improve that accuracy. It seems that the voltage dividers are almost perfect (very uniform between ranges) so just a small tweak of that trimpot!
As an aside, it would be an improvement to swap out those horrid little trimpots for a set of multi-turn wirewound pots. Make the setting easier plus more stable than the carbon pots over time.
I could do a trimpot swap, but then I'm up against the inaccuracy of reading an analogue gauge anyway.
I've swapped trimpots out on other gear before for the exact reasons you mention (like my Yokogawa 2554 volt/current standard I made a previous video on), but I don't think the improvement in accuracy would have much effect when the display isn't digital.
Plus it is still under warranty, so it'll have to wait before I start modding it anyway. :D
spark gap?
Very nice, I want one.
Do you know why these multimeter has ohms adjuster ?
And you can't get real time needle movement because it has fet across it. It delays
You can compare under $50 analog meter's needle moving speed with this one. This multimeter use for mesasurement not for fault findings like DMMs and diagnose
The adjustment is to allow you to zero the ohms scale in each range before taking a measurement.
Excelente
Hey great video, how do I get in contact with Mr. NFM.
You just did. :)
What's up?
@@NearFarMedia Two things, I have something to send to you for review and perhaps use. Just a little electronic project. Not so soon as the current situation not okay yet. The other thing, I wish to communicate through email. my email is yusdiytechATgmaildotcom
saya punya sanwa cd800a made in china, apakah itu asli? makasih...
Hello.
I have 2 of them. One is damaged due to a leak of the 9v battery. Trimpots went damaged. The other one keeps stored without the batteries. Other than that fragility, they are wonderful. Good price for a FET input Multimeter.
Don't you need to re-zero when you change resistance scales. I have this meter & it equals the Simpson swing arm meters !!!
OMG 2 WHOLE boxes! WITH Free shit!?... fucken' love free shit! lul ;D
Yeah, I couldn't believe my luck! The boxes were a bit expensive, but the free stuff inside made up for it in the end. :D
You need to zero the needle for ohms measurement before measuring ohms!
Those are Spark Gaps
Sanwa EM7000 is an excellent meter (MADE IN JAPAN)! You tested it wrong.
I love mine but don't place it anywhere near magnetic objecst such as fans, TV sets etc. it throws the meter out of wack !
Ohhh, AND, just one final thing, the SANWA user manual ..specifically warns you ..NOT, to ..Change ..Ranges, on the meter, WHILE, it is ..connected to ANY energised circuit..!! 🙄🙄
Each time you change the resistor scale x1 x10 x100 etc... you need to ZERO it first.
Please Zero Ohm before use😅
a
They did it wrong. Using a chopper amplifier is way more advantagous than using a FET differential amplifier. There is a circuit for the similar EM3000 on the internet.
You didn’t, ZERO, the resistance range before you tried using it on your “home-brewed, precision resistance box” ..BOOF-head…!! 🙄🙄
Too expensive. I got one for $11 on Aliexpress.
A Sanwa for $11? If so, it won't be genuine...
If it's another brand, I wouldn't trust it to be safe or accurate as far as I could throw it. :)