i only ever used one before and I’ve forgotten how to set the device to test the resistance of an atty. What setting do I want?
thanks
thanks
Dmm
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Thanks. I still get nothing so I’m not sure what’s wrong. It reads +1 and never zeros out.
Zero change when I apply to the pos and neg
Zero change when I apply to the pos and neg
They usually read +1 just to show continuity when the resistance is lower than that particular DMM is able to measure. Most of those style DMM's are not real good at reading sub-ohm ranges.
Thanks for the help but I’m not trying to measure sub-ohm.
It’s a proper hybrid and although I am certain of what the 6 wraps will be on any atty I’d be happier with the dmm showing me the 1.2 that I’m looking for before I fire away
It’s a proper hybrid and although I am certain of what the 6 wraps will be on any atty I’d be happier with the dmm showing me the 1.2 that I’m looking for before I fire away
Because it’s a “proper” hybrid I can’t put it on the ohm reader or any other mod just to check
If you used that method before and it worked, then it could be that there is some internal short in the atomizer causing it to actually be really low ohm. Low batteries in the DMM may also be the culprit.
You can test the DMM's accuracy by measuring the resistance of just a straight piece of wire roughly the same length as what you would wrap. You don't even have to cut it off the spool. Just unspool several inches, hold one lead touching the end of the wire, and the other lead touching several inches further down the wire. If you get a good reading, then something is going on inside the atomizer. If not, then something is going on with the DMM.
Thank you. Yeah I’ll try that with the spool.
No, it was another atty and another dmm and a while ago.
These are both new. Cheers
No, it was another atty and another dmm and a while ago.
These are both new. Cheers
Remove the leads from the meter. Take a piece of bare wire and short between the two lead sockets. If it still reads +1, the meter is NFG. If it zeros out, then one of the leads is NFG.
So I just looked up that DMM, I was hoping to find the measurable range for resistance and found some...horrible reviews on Amazon (including one pasted below). I didn't realize this was the same one that Harbor Freight gives away for FREE they are so cheap. So you should consider getting a better DMM.
___________________________________________________________
Criminally dangerous design
I would not trust this meter even as a throwaway. This is the meter they often give away free via coupon next to the monthly 20% or 25% off coupon and is usually on sale for $5.49 to $5.99.
What I don't like:
The banana plugs and jacks are non-standard safety shroud. So these leads won't work in something else, and standard safety shrouded leads won't work in these meters. I thought they might be OK for the battery test function, but a 9V battery that showed about 9.5V on three other known-good meters displayed as 5.7V on this meter. I checked the voltage using another meter while it was connected to this meter, in case the internal load was loading the battery down. Same result.
In addition, the insulation on the test leads is rather stiff, and to my eye (over 20 years as an ET and with an EET degree a few years ago and a recently expired IPC inspection certification) the insulation looks too thin for me to feel safe measuring the 1000V DC or 750V AC the meter is rated for.
Internally, the banana jacks are on a separate PCB connected only by large solder blobs bridging the two boards. This is a terrible design, prone to cracking solder. Putting the leads in and taking them out, or even just pushing on the case or leads will flex the solder blobs, eventually leading to cracking. The board with the banana jacks is held in only by a tiny pin from the removable back, and a small plastic tab that broke easily when I took the meter apart. So maybe you are using the meter to check an AC outlet or light fixture to make sure you shut off the correct breaker, and the solder has cracked. The meter says zero volts. You are now trusting your life to a poor design that would never pass IPC inspection of -any- level.
Also internally, the connection from the board to the LCD glass is via the standard vertically conductive silicone, but the glass is mounted to the plastic case rather than directly to the board. The glass is held in only by the pressure of the PCB pressing against the silicone conductive strip and a small plastic tab. So flexing of the relatively soft plastic case will eventually cause failure of the display. Merely bouncing it around in a toolbox/bag or even just turning the selector switch flexes the case. In addition, the PCB is visibly curved due to this method of attachment, which can potentially cause broken solder joints to the surface mount components.
Removing the board and doing a closer inspection revealed errors in assembly above and beyond the poor design.
The PCB with the banana jacks wasn't properly pushed in all the way before the solder blobs were applied, so it is sitting up at an angle. The 9V battery wiring was poorly soldered, the positive lead isn't even soldered in. There are multiple places where solder blobs cover the board, or are strung across traces including a long thread of solder connected to the fuse. This potentially creates places where using the meter close to its maximum voltage could cause arcing internally. A polyester capacitor is incompletely covered. The thick gauge copper wire used as a shunt for the 10A range was adjusted up in resistance by partly cutting it multiple times, creating stress points that could fail while being used at high currents, which could cause a high temperature arc to form.
In addition: What happened to autoranging? DMMs got so even the cheapest had autoranging. Now you have to buy at least a mid-range to get autoranging.
I would not have as much of a problem with these meters if they were only rated to, say, 20V and 500mA max. Well, I'd still have a problem with them because of the solder balls and solder icicles, and the generally poor construction.
A friend of mine, in spite of my warnings, used one of these Centech red meters when troubleshooting his dryer.
The exact failure that I worry most about with this meter happened: He thought he had the leads plugged in correctly, but instead had the red lead in the 10A jack. He then plugged the leads into a 240Vac outlet.
He said there was a tremendous bang and the meter blew apart. What saved him from serious injury was that he had the meter sitting on the ground, not in his hand. I wish he'd gotten pictures so I could share them.
Before you berate me for worrying about what a meter does when it is misused- this is the difference between a good meter and a bad meter. The good meter is built to fail in a non-life threatening way when something goes wrong, -especially- operator error. Design can only go so far, but protection against a meter being on the wrong scale or having the leads plugged in to the 10A position and being connected to a voltage source are basic and necessary.
See Dave Jones of EEVBlog on Youtube - his videos covering multimeters talks about these safety issues.
___________________________________________________________
Criminally dangerous design
I would not trust this meter even as a throwaway. This is the meter they often give away free via coupon next to the monthly 20% or 25% off coupon and is usually on sale for $5.49 to $5.99.
What I don't like:
The banana plugs and jacks are non-standard safety shroud. So these leads won't work in something else, and standard safety shrouded leads won't work in these meters. I thought they might be OK for the battery test function, but a 9V battery that showed about 9.5V on three other known-good meters displayed as 5.7V on this meter. I checked the voltage using another meter while it was connected to this meter, in case the internal load was loading the battery down. Same result.
In addition, the insulation on the test leads is rather stiff, and to my eye (over 20 years as an ET and with an EET degree a few years ago and a recently expired IPC inspection certification) the insulation looks too thin for me to feel safe measuring the 1000V DC or 750V AC the meter is rated for.
Internally, the banana jacks are on a separate PCB connected only by large solder blobs bridging the two boards. This is a terrible design, prone to cracking solder. Putting the leads in and taking them out, or even just pushing on the case or leads will flex the solder blobs, eventually leading to cracking. The board with the banana jacks is held in only by a tiny pin from the removable back, and a small plastic tab that broke easily when I took the meter apart. So maybe you are using the meter to check an AC outlet or light fixture to make sure you shut off the correct breaker, and the solder has cracked. The meter says zero volts. You are now trusting your life to a poor design that would never pass IPC inspection of -any- level.
Also internally, the connection from the board to the LCD glass is via the standard vertically conductive silicone, but the glass is mounted to the plastic case rather than directly to the board. The glass is held in only by the pressure of the PCB pressing against the silicone conductive strip and a small plastic tab. So flexing of the relatively soft plastic case will eventually cause failure of the display. Merely bouncing it around in a toolbox/bag or even just turning the selector switch flexes the case. In addition, the PCB is visibly curved due to this method of attachment, which can potentially cause broken solder joints to the surface mount components.
Removing the board and doing a closer inspection revealed errors in assembly above and beyond the poor design.
The PCB with the banana jacks wasn't properly pushed in all the way before the solder blobs were applied, so it is sitting up at an angle. The 9V battery wiring was poorly soldered, the positive lead isn't even soldered in. There are multiple places where solder blobs cover the board, or are strung across traces including a long thread of solder connected to the fuse. This potentially creates places where using the meter close to its maximum voltage could cause arcing internally. A polyester capacitor is incompletely covered. The thick gauge copper wire used as a shunt for the 10A range was adjusted up in resistance by partly cutting it multiple times, creating stress points that could fail while being used at high currents, which could cause a high temperature arc to form.
In addition: What happened to autoranging? DMMs got so even the cheapest had autoranging. Now you have to buy at least a mid-range to get autoranging.
I would not have as much of a problem with these meters if they were only rated to, say, 20V and 500mA max. Well, I'd still have a problem with them because of the solder balls and solder icicles, and the generally poor construction.
A friend of mine, in spite of my warnings, used one of these Centech red meters when troubleshooting his dryer.
The exact failure that I worry most about with this meter happened: He thought he had the leads plugged in correctly, but instead had the red lead in the 10A jack. He then plugged the leads into a 240Vac outlet.
He said there was a tremendous bang and the meter blew apart. What saved him from serious injury was that he had the meter sitting on the ground, not in his hand. I wish he'd gotten pictures so I could share them.
Before you berate me for worrying about what a meter does when it is misused- this is the difference between a good meter and a bad meter. The good meter is built to fail in a non-life threatening way when something goes wrong, -especially- operator error. Design can only go so far, but protection against a meter being on the wrong scale or having the leads plugged in to the 10A position and being connected to a voltage source are basic and necessary.
See Dave Jones of EEVBlog on Youtube - his videos covering multimeters talks about these safety issues.
Thank you @Rossum ill try that later
Thank you @ScottP
I appreciate the concern. I’m more than capable of understanding the reading to a degree to determine the safety. It isn’t as though I am completely unaware as to what the dmm should read in relation to the build for this atty.
It was recommended by a gentlemen (or possibly a gentle-woman) on this forum not too long ago. Being in the U.K. it was hard for me to get but I found one new unit on eBay and it was real cheap (not quite free though) so I thought I’d give it a go. I’m only looking for a rough guide as I want 1.2 and so a large margin of error is fine. If the same margin correlates to one of my other attys then I can work out the build (kind of).
Thank you @ScottP
I appreciate the concern. I’m more than capable of understanding the reading to a degree to determine the safety. It isn’t as though I am completely unaware as to what the dmm should read in relation to the build for this atty.
It was recommended by a gentlemen (or possibly a gentle-woman) on this forum not too long ago. Being in the U.K. it was hard for me to get but I found one new unit on eBay and it was real cheap (not quite free though) so I thought I’d give it a go. I’m only looking for a rough guide as I want 1.2 and so a large margin of error is fine. If the same margin correlates to one of my other attys then I can work out the build (kind of).
Thank you though. I’ll do some more reading and perhaps it will become throwaway. Who knows.
I do value my hands though...
I do value my hands though...
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