Nice work on checking out the software! Pretty cool it can extract out all the manual save points. I'm guessing it if you just read the values over the raw COM port text you wouldn't even need to install anything either. Majority of the reason to have an "integrated" resistor network is so that all of their temperature coefficients match very closely, so even if the values drift, their ratios won't. I guess it's not quite needed for 4.5 digit DMM.
Yes, you could issue SCPI commands like "comf" to change functions and "meas" to get the values. I think you are right on the resistor packs. You can add to the that some ADCs don't have individual compensation for the analog channels. Older designs especially. My old Fluke 8050 has a Caddock net in it. Of course, it was fairly high end in it's day.
I'm fairly sure it would be due to the meter's ability to determine the cold junction temperature and do the math to compensate for it. Google "cold junction compensation for thermocouples". There will be a little math an physics involved.
Just putting the Kelvin clips in the holes does not give you 4-wire mode. Plug some 4mm connectors in and clip the leads on. You need to get the feed and sense parts of the Kelvin clip apart.
It does not introduce as much error as you might to think. Your idea to put banana plugs in would create about the same error of about 2 cm of un-corrected wire length. The measurement node is where the kelvin clips make contact. Whether or not that contact is across the component leads, or the component leads meet that point in another way is immaterial. The only error will be the unaccounted for conductor from that node to the internal element of the component. The way I did it, they measurement node is where the clips first contact each other which might a cm or 2 from the contact point to the banana socket. Virtually the same would be true if banana plugs were inserted.
@@uni-byte The problem with simply dropping the probes in the hole is that you have no idea how good the contact is. And the sense wires are now on the wrong side of that uncertain contact so they have no way of correcting for it. Plugging in a 4mm connector (no insulating cap) allows you to make contact close to the hole, but now with the sense wires doing their proper task.
@@donepearce Ahh, I get what you mean and generally I'd agree. However, in this case the kelvin clips have sharp gold plated edges that when put into a banana socket make very good contact.
I have not had my hands on one, but the 4-wire Ohms mode and the form factor alone are worth the extra few dollars. You can actually stack stuff on this, but not on the XDM1041 so it makes better use of your shelf space. The front accessible fuse is also a BIG plus.
I've found that temperature measuring functions are by far the sloppiest measurements in hobby-level gear. They are all over the place. I'd stick to Omega gear for commercial applications. As far as calibration of hobbyist gear, I use distilled water turned to crushed ice and water. I put the thermocouple in a Styrofoam cup of it and stir it while calibrating and I have a good zero degree reference. Mildly boiling the water and adjusting for barometric pressure gives me a good 100C reference point, so I have at least 2 good points on the line. If the circuit is linear I'm in good shape. If it's not, I can at least be closer than I was, and I can toss out any device that can't be set to those 2 points. I do this every couple of years just to be sure that things haven't drifted very far. My gallon of distilled water was very cheap, (I don't buy lab-grade, just off the shelf,) and I'm still on my first gallon. It's nice to be able to create an effectively (at least close) primary standard for a hobbyist lab. I can't do that for voltage.
Thanks for your effort.
You're welcome.
Nice work on checking out the software! Pretty cool it can extract out all the manual save points. I'm guessing it if you just read the values over the raw COM port text you wouldn't even need to install anything either. Majority of the reason to have an "integrated" resistor network is so that all of their temperature coefficients match very closely, so even if the values drift, their ratios won't. I guess it's not quite needed for 4.5 digit DMM.
Yes, you could issue SCPI commands like "comf" to change functions and "meas" to get the values. I think you are right on the resistor packs. You can add to the that some ADCs don't have individual compensation for the analog channels. Older designs especially. My old Fluke 8050 has a Caddock net in it. Of course, it was fairly high end in it's day.
Big help nice job thanks for your time
Thank you for watching.
1:45 It's odd that the meter shows 00.00 Ohms when autoranging when you move to a different resistor.
Yes, a lot of times it is zeroed out as the ranges change. I guess that's a decision that was made in the firmware over on teh digital side.
Can you make a video to just figure out why the temperature probe reading varies so much across your 3 instruments?
I'm fairly sure it would be due to the meter's ability to determine the cold junction temperature and do the math to compensate for it. Google "cold junction compensation for thermocouples". There will be a little math an physics involved.
Just putting the Kelvin clips in the holes does not give you 4-wire mode. Plug some 4mm connectors in and clip the leads on. You need to get the feed and sense parts of the Kelvin clip apart.
It does not introduce as much error as you might to think. Your idea to put banana plugs in would create about the same error of about 2 cm of un-corrected wire length. The measurement node is where the kelvin clips make contact. Whether or not that contact is across the component leads, or the component leads meet that point in another way is immaterial. The only error will be the unaccounted for conductor from that node to the internal element of the component. The way I did it, they measurement node is where the clips first contact each other which might a cm or 2 from the contact point to the banana socket. Virtually the same would be true if banana plugs were inserted.
@@uni-byte The problem with simply dropping the probes in the hole is that you have no idea how good the contact is. And the sense wires are now on the wrong side of that uncertain contact so they have no way of correcting for it. Plugging in a 4mm connector (no insulating cap) allows you to make contact close to the hole, but now with the sense wires doing their proper task.
@@donepearce Ahh, I get what you mean and generally I'd agree. However, in this case the kelvin clips have sharp gold plated edges that when put into a banana socket make very good contact.
@@uni-byte I feel an experiment coming.
@@donepearce Kind of did that in the video when I compared teh result with the REL mode. No?
Have you had a chance to look at the XDM 1041 and do you feel the 2041 is worth the $40 difference?
Thanks!
I have not had my hands on one, but the 4-wire Ohms mode and the form factor alone are worth the extra few dollars. You can actually stack stuff on this, but not on the XDM1041 so it makes better use of your shelf space. The front accessible fuse is also a BIG plus.
I've found that temperature measuring functions are by far the sloppiest measurements in hobby-level gear. They are all over the place. I'd stick to Omega gear for commercial applications. As far as calibration of hobbyist gear, I use distilled water turned to crushed ice and water. I put the thermocouple in a Styrofoam cup of it and stir it while calibrating and I have a good zero degree reference. Mildly boiling the water and adjusting for barometric pressure gives me a good 100C reference point, so I have at least 2 good points on the line. If the circuit is linear I'm in good shape. If it's not, I can at least be closer than I was, and I can toss out any device that can't be set to those 2 points. I do this every couple of years just to be sure that things haven't drifted very far. My gallon of distilled water was very cheap, (I don't buy lab-grade, just off the shelf,) and I'm still on my first gallon. It's nice to be able to create an effectively (at least close) primary standard for a hobbyist lab. I can't do that for voltage.
That's a great method and I've used that in the past for a few devices I have.
Has anyone found a way to set default high speed instead of low?
I'm not aware of any way. It would be nice feature though.