EEVBlog 121GW Discussion thread

[firewalker]

There was a python script for communication with the meter under GNU/Linux? Do I remember correctly? Any links?

Alexander.

[Seppy]

Just a note for Dave or David:
The review section on the products page for this meter is starting to attract spam. You might want to take measures to prevent these (I'm not sure if email confirmation is required), or do some moderation.

Thanks! I have resolved that, its a daily thing. I've been doing it manually, our Spam filter is a bit broken I think.

[EEVblog]

A video testing the 50 ohm range at low values:

[Dr. Frank]

Hi Dave,
I don't recognize, which problem you wanted to examine...

The 50 Ohm range had two different probs, than simply being in/out of  spec.

First, if you apply F.S. of 50 Ohm, you may encounter an unstable reading on the last two digits, although it should be stable at this high test current, and also compared to the ranges of 500 Ohm to 500 kOhm. Even the 5M Ohm is stable to the last digit with FW 1-26.
Also, it's a bit tricky to make a correct REL setting, when shorting its input.

The 50 Ohm range resolves 1mOhm, which is a great favor of your 121GW. Clearly, you need to use REL to zero any cable resistance, so afterwards to measure precisely resistance in the Ohm range, with 1mOhm resolution, and even accuracy.

I was disappointed though, because the calibration of UEI had introduced a threshold, by too high residual zero calibration, which also seemed to affect this described low ohm measurement.

[EDIT:]
So if you short the 121GW with successively lower resistance from your resistor box with 10 mOhm resolution, you can check,  when this obvious threshold steps in.. maybe at about 100..200mOhm, which might suddenly give a straight reading of 0.000 Ohm.

Anyhow, I have improved the zero calibration by using a massive short, and then the gain by a precise 50.000 Ohm reference.

After that procedure, I really can use the 121GW to precisely measure resistance in the mOhm range, either correctly zeroing cables, or determine residual resistance of my resistor box, or making measurements of 10.000... 50.000 Ohm resistors, much better than the spec.

That 1 mOhm resolution feature is a great plus of the 121GW, so I would recommend to make an effort on proper calibration.

Frank

[M4x]

I've received my meter together with the probes from UEI. I can take of a kind of plastic / rubber cap to get to the thread on the tips. I assume that the idea behind these threads is to be able to screw a banana plug tip to it to be able to connect it to some clamps for example (to to to ;-) ).

When I'm checking out the Brymen test leads online, it looks to me like they always come with those banana plug tips.
https://www.welectron.com/Brymen-BL21S2-T4SC-Silicone-Test-Leads
I've assumed that the UEI leads would come with something like that too.

Are they missing in my package or does nobody have received them?

Max

[1anX]

Gold plated, screw on banana adapters like in the picture you posted came with my leads!

[ornea]

The threaded lead banana tip adapters came with my leads.

[IanB]

I think the meters were meant to come with the Brymen leads that have the banana plug adapters, but due to a shortage of supply some meters were shipped with leads from another vendor. You would have to search back through the thread history to find the post where Dave mentioned that.

[darik]

A video testing the 50 ohm range at low values:

@1:42 - There's one of those spurious 50 Mohm range readings popping up and holding up the autoranging. They look so much like a real reading. You have to think about what you're seeing. And I'm pretty sure they delay the autoranging by a half second or more when they happen. Mine will do that 90% of the time when I short the probes.

[Candid]

I can second that.

[M4x]

I think the meters were meant to come with the Brymen leads that have the banana plug adapters, but due to a shortage of supply some meters were shipped with leads from another vendor. You would have to search back through the thread history to find the post where Dave mentioned that.

I would have preferred the Brymen leads but you can read on the product page that the meter comes with the Brymen OR the UEI leads, depending on the supply situation.

NOTE: The meter may come with either Brymen (gold) probes or UEI (nickel) probes depending upon availability at the time. Both are high quality silicone rubber probes.

Source: https://www.eevblog.com/product/121gw/

Therefore Brymen or UEI are both fine. What I'm missing is the banana plug adapter.

Max

[Muttley Snickers]

Did your UEI leads come with a part or model number ?.   

I suspect they might be the UEI ATL57 silicone leads which don't come with the screw on banana plug adaptors, they are supplied with screw on alligator clips instead from what I saw on the UEI web page.

[M4x]

Unfortunately I can't find a model number. From the UEI website, the leads could although be the ATL55 (Cat III 1000V in the description; https://www.ueitest.com/products/accessories?page=1&tid_1=All&tid=24).

I've received the 121GW with 8GB SD-card inserted, temperature probe, certificate, a case and the test leads WITHOUT banana plugs or crocodile clips or something like that.

I've attached the product picture of the ATL55 from www.ueitest.com and some pictures I took from the test leads I've received with the 121GW.

Max

[Candid]

Yours seem to be the ATL55 because they are "only" CAT III 1000V. The ATL57 should be CAT IV 1000V and silicone cables. So it looks as if you got the wrong leads because EEVBlog shop states that both are silicone wires and this is not for the ATL55 as far as I can see from the UEI data sheets. And, because when you get it with Brymen leads they are part of it, you should get the 4mm banana shrouded plugs too. So I would contact Dave/David and clear this.

[M4x]

Oh, I think you're right! I've attached a picture from the "data sheet": https://www.ueitest.com/sites/default/files/product-resources/L322_Accessories%202017.pdf

[Candid]

That's it. If you got silicone leads they should be very flexible. The PVC ones are most time very shiny, the silicone ones are often more mat.

[Muttley Snickers]

The leads shown in the image posted above are definitely the ATL57 silicone series which are identifiable by the ridiculously long strain relief, the ATL55 series have a shorter strain relief.

Use this UEI page for better images and detail.
https://www.ueitest.com/search/node/leads

[ELzekio]

I really don’t know to much about probe material, but the UEI probes I received with my meter seem a lot more malleable than any of my other pvc probes I’ve got. They sure feel like silicone.



Also if you type in the UL number printed on the meter probes on google

E496219

This link to the UL website will pop up saying they are the ATL57 probes.
http://productspec.ul.com/document.php?id=PICQ.E496219

[M4x]

You're both right, from the touch and look, I think it's silicone. And if you click on "HI-RES PICTURE" on the UEI site, you'll get another picture for the ATL55 than shown as a thumbnail image in the overview. I've attached both pictures. Like Muttley Snickers said, I've definitely received the ATL57 leads.

And I can't find banana plug addons at the UEI website. The banana plugs would be very useful to me. By searching for "Screw-On" I can only find the AAC3 Alligator Clips (https://www.ueitest.com/products/accessories/aac3). I'm thinking about getting the Brymen BL21S2-T4SC Silicone Test Leads (https://www.welectron.com/Brymen-BL21S2-T4SC-Silicone-Test-Leads).

Anyway, I'm wondering if my test leads should've come with some "tip addons".

Max

[Muttley Snickers]

Anyway, I'm wondering if my test leads should've come with some "tip addons".

As mentioned earlier, I don't think UEI does the screw on banana plug adaptors which you have seen supplied with the Brymen leads, nothing is wrong with that either as various manufacturers do things in different ways and have differing products lines.

I think UEI need to tidy up some of those accessory pages as some of the images appear to be incorrect or misleading, particularly in regards to the test leads which makes it confusing for some. The images also give the impression that alligator clips are supplied with certain test lead sets but are instead a separate accessory.

[Candid]

The leads shown in the image posted above are definitely the ATL57 silicone series which are identifiable by the ridiculously long strain relief, the ATL55 series have a shorter strain relief.

Use this UEI page for better images and detail.
https://www.ueitest.com/search/node/leads

UEI uses the same picture for both on their website so you cannot belief what you see. When you open the data sheet you get a pdf where they use the exact same picture for both ATL55 and ATL57.

When you click on the link "HI-RES PICTURE" for the ATL55 you get a picture of completely other leads () and when you click on the "HI-RES PICTURE" link for the ATL57 you get a low res picture of the leads from the PDF.

[Muttley Snickers]

The leads shown in the image posted above are definitely the ATL57 silicone series which are identifiable by the ridiculously long strain relief, the ATL55 series have a shorter strain relief.

Use this UEI page for better images and detail.
https://www.ueitest.com/search/node/leads

UEI uses the same picture for both on their website so you cannot belief what you see. When you open the data sheet you get a pdf where they use the exact same picture for both ATL55 and ATL57.

When you click on the link "HI-RES PICTURE" for the ATL55 you get a picture of completely other leads () and when you click on the "HI-RES PICTURE" link for the ATL57 you get a low res picture of the leads from the PDF.

This is not correct, if you follow the link I provided shown in the first image below it offers a 360° view of the ATL57 lead set which clearly shows the extended strain relief as can be seen in the third image, the web page that M4x linked does not offer up the 360° view option which aids to hinder proper identification as can be seen in the second image, my work here is done.   

[Candid]

So you can see that UEI made the mistake and placed wrong pictures and 360° views. At the ATL57 e.g. they write "CATIV Test Leads (Silicone)". The leads on the picture are red and/black. When you open the 360° view of the ATL57 you see red/grey test leads with the text "CATII 1000V" on it. In the "data sheet" for both ATL55 and 57 they take the exact same picture (what I think is the ATL57).

At the ATL55 look on the HIGH-RES PICTURE what is totally different again. And at the ATL55 there is no 360° view. I am pretty sure we would find a fourth variant of leads there 

So we both are correct and UEI is the culprit  I am starting to see why the firmware of the 121GW is a little "confused" so seemes the company to be. 

The links I checked are:
https://www.ueitest.com/products/accessories/atl57
https://www.ueitest.com/products/accessories/atl55

[logictom]

Can anyone point me in the direction of a supplier for replacement fuses at reasonable price and preferably in Australia, failing that a UK supplier? I am after the 400mA but I may as well pick up both while I'm at it

[tautech]

Can anyone point me in the direction of a supplier for replacement fuses at reasonable price and preferably in Australia, failing that a UK supplier? I am after the 400mA but I may as well pick up both while I'm at it

Daves shop but it show he's out of stock.
https://www.eevblog.com/product/multimeter-fuse-pack/

Send him a message.