Author Topic: Test Equipment Anonymous (TEA) group therapy thread  (Read 1723348 times)

mansaxel, Addicted2AnalogTek, mnementh, nixiefreqq, med6753, Mortymore, Johnny10, scl, BU508A, Cubdriver, Wolfgang, Kosmic, Specmaster, calin, jjoonathan and 20 Guests are viewing this topic.

Online mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11125 on: May 23, 2018, 03:41:32 pm »


Bet you a dollar after your conversation re: the Fluke calibration software, they found that they HAD the right software modules, and after a little digging, ALSO had the correct cabling to do the cal via the GPIB. Wouldn't be surprised if they didn't need to move the switch to do it that way either. Probably all the techs who actually knew how to use the software had already retired or moved on to better-paying jobs.

mnem
*Back out into the suck*
Says in the manual it won't talk cal data to HP-IB if the cal switch wasn't turned.

I bet they employ fucktards.

Well, so much for that excuse. But the fucktard factor is kindof where I was headed with the rest of that suggestion. ;)

mnem
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Online mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11126 on: May 23, 2018, 03:45:24 pm »
Except you didn't a valid Cal cert, and you were hoping to use this meter to validate the accuracy of your MS7221...

mnem
Fu**... we've just gone recursive again.
Trust you to spot the flaw in my logic  :palm: Its going to be more then accurate enough for me when those reading are also supported by, let me see now, about 14 or 15 other meters and it would be an absolute fluke if there all of their game and were all wildly out of calibration  :-DD

Surprising thing that the MS7221 seems to be at full whack of by about 4mV so I think I can live with that knowledge so currently there's no truth in the rumor that I'm just to top myself but I might have a celebratory cup of tea and a biscuit, shouldn't do, I'm big enough already but I feel like celebrating to sod it thats what I'm going to do  :-DD

Truly, 'tis a sad, SAD day when I am the voice of reason... ANY reason.  :-DD


mnem
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Online mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11127 on: May 23, 2018, 04:29:58 pm »


Sometimes I think to myself... "Maybe I need to re-evaluate Guugle as my default search engine..."

This it what it returned when I searched for this random CyrusTek-based RF module I found in a kids toy.  :palm:

mnem
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Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11128 on: May 23, 2018, 05:12:40 pm »
I used a function generator and another meter as a reference. You only need to cal on the 3v range. I think you’re just calibrating the AC converter and the rest is based on the DC cal.
Am I doing this right, I have my function generator all set up with frequency set to 50Hz, sine wave and output connected a voltmeter and adjusted to read 1V.

3478A set in CAL mode, follow same procedure as for DC, ie, short terminals, blue button, then SGL TRIG button and the display shows 3.0000 and all the other indicators to with CAL mode? Where in blue hell did the 3 come from? There is nothing other than a pair of long nose pliers in the input jacks? 
« Last Edit: May 23, 2018, 05:20:28 pm by Specmaster »
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Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11129 on: May 23, 2018, 05:19:56 pm »
It doesn’t need zeroing on ACV I don’t think. Check the cal steps in the manual!

I did mine with the manual in front of me and carefully followed the instructions.
« Last Edit: May 23, 2018, 05:22:03 pm by bd139 »
 

Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11130 on: May 23, 2018, 05:31:14 pm »
So am I, just re-reading the instructions again and it seems I am doing it right, but have to pop out and pick up SWMBO so I'll try it again when I get back. The only thing I'm doing wrong is zeroing it, but that to my mind does not explain why the screen is reading 3.0000 with no input connected?

I have done the 2W resistance cal so now I have DCV, DCA,  \$\Omega\$ 2W and 4W done, its just the AC now and I'll be a happy bunny and less of a grumpy old man  :-DD

I'm very impressed with the little Mastech MS7221 calibrator too, especially at the price I stole it for  :-DD :-DD :-DD
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Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11131 on: May 23, 2018, 05:36:50 pm »
No, the 2w  \$\Omega\$ is not calibrated, it can't be if the 4w is done, it takes its approximation from the 4w though as it within a hairs width of the value  :-+

The ACA does have to be set as at 300mA, will investigate this later.
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Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11132 on: May 23, 2018, 05:48:04 pm »
If it’s reading 3.0000 with no input it’s asking for 3.0000 to be applied.

AC amps should be fun. I’d stuff a 1k resistor, the FG, a known good meter and the 3478A in series and crank it as close as you can get to 3v and adjust the 3478A cal parameter.

Resistors I have a set of 0.1% RN55D’s and made the rest of the values up from 1% ones in series/parallel and measured them on the U1241C
 

Online mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11133 on: May 23, 2018, 05:56:10 pm »
I believe tgzz (or was it tautech?) mentioned earlier that the default is 3V, and that you can Cal at 1/3 scale (1V), but inaccuracy would be 3 times as great at the high end of the scale.  :bullshit:  You would have to bring the displayed number down to read 1V, which I think will also be LOTS of button clicks...  :scared:


mnem
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Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11134 on: May 23, 2018, 05:58:46 pm »
I was well prepared for this after Daley Thompson’s Decathlon, one of the finest games ever.
 

Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11135 on: May 23, 2018, 06:16:28 pm »
If it’s reading 3.0000 with no input it’s asking for 3.0000 to be applied.

AC amps should be fun. I’d stuff a 1k resistor, the FG, a known good meter and the 3478A in series and crank it as close as you can get to 3v and adjust the 3478A cal parameter.

Resistors I have a set of 0.1% RN55D’s and made the rest of the values up from 1% ones in series/parallel and measured them on the U1241C
I assume then if I stuff in as near to 3V as possible that I'd have to adjust the reading to reflect that of the other known meter?

When it comes to AC amps, do you mean 300mA rather then 3V as I wont be reading volts on the other meter??
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Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11136 on: May 23, 2018, 06:21:03 pm »
I believe tgzz (or was it tautech?) mentioned earlier that the default is 3V, and that you can Cal at 1/3 scale (1V), but inaccuracy would be 3 times as great at the high end of the scale.  :bullshit:  You would have to bring the displayed number down to read 1V, which I think will also be LOTS of button clicks...  :scared:


mnem
Maybe we should do a musical number now...
Yes you are correct, but it wouldn't be a lot of button clicks, just a marathon button hold while it went from 3.0000 to 2.9999, to 2.9998 all the way to 1.0000 there is no speed up function unlike many other things were the speed gets faster the after holding the button down for a period, if there is it isn't working on mine. :(
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Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11137 on: May 23, 2018, 06:28:39 pm »
If it’s reading 3.0000 with no input it’s asking for 3.0000 to be applied.

AC amps should be fun. I’d stuff a 1k resistor, the FG, a known good meter and the 3478A in series and crank it as close as you can get to 3v and adjust the 3478A cal parameter.

Resistors I have a set of 0.1% RN55D’s and made the rest of the values up from 1% ones in series/parallel and measured them on the U1241C
I assume then if I stuff in as near to 3V as possible that I'd have to adjust the reading to reflect that of the other known meter?

When it comes to AC amps, do you mean 300mA rather then 3V as I wont be reading volts on the other meter??
If you can get 300ma out of your FG. Unlikely as at 50 ohms that’s 42v pp ish.
 

Offline Mr. Scram

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11138 on: May 23, 2018, 06:31:03 pm »
I'm sorry you're having all these problems, Specmaster. Looking at it from the perspective of a neutral observer it's quite an entertaining story and there are a few lessons to be learned as well.
 

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11139 on: May 23, 2018, 06:32:20 pm »
If it’s reading 3.0000 with no input it’s asking for 3.0000 to be applied.

AC amps should be fun. I’d stuff a 1k resistor, the FG, a known good meter and the 3478A in series and crank it as close as you can get to 3v and adjust the 3478A cal parameter.

Resistors I have a set of 0.1% RN55D’s and made the rest of the values up from 1% ones in series/parallel and measured them on the U1241C
I assume then if I stuff in as near to 3V as possible that I'd have to adjust the reading to reflect that of the other known meter?

When it comes to AC amps, do you mean 300mA rather then 3V as I wont be reading volts on the other meter??
If you can get 300ma out of your FG. Unlikely as at 50 ohms that’s 42v pp ish.
I could get 300mA easily enough via a variac but at 50Hz?
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Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11140 on: May 23, 2018, 06:33:00 pm »
Variac isn’t going to be voltage stable enough. Mains is all over the shop.
 

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11141 on: May 23, 2018, 06:42:55 pm »
Variac isn’t going to be voltage stable enough. Mains is all over the shop.
Yes you're right, I have a look at that in more detail when I get to doing the AC Amps and I'll get 300mA out of my wimpy Chinese FG (could be the next item in my tool kit to be replaced) it seems almost everytime I use I have to fiddle with it to get the membrane buttons to respond correctly  :palm:
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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11142 on: May 23, 2018, 07:44:26 pm »
Wow, I know have a fully functioning meter that not only checks out against my calibrator but even more importantly agrees with my other meters give or take the odd least significant digit by 1 or 2 counts as these are often bouncing around due to noise etc, I'm not at all bothered by that  :phew:

Thanks to bd139 for his assistance and no I don't think I'll bother getting this checked over by any other Lab because I doubt its going to be worth it and also of course apart from RS the only other lab remotely near me is Calmet, who say that can do it but it is not known to how many digits, unless bd139 does as he spoke to them? I have personally spoken to quite a few labs, many declined because they could not do it, and there was 3 others that claimed that they could calibrate it to either 2 or 3 digits and if I wanted 4 digits, then 1 on those said that they could farm it out a sister company but none said they could do a full 5 digit cal.

Should I email the lab that returned it uncalibrated and FOC because they couldn't get it to retain the calibration and tell them that what they couldn't do I've managed to do?  >:D
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Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11143 on: May 23, 2018, 07:49:25 pm »
I would shitpost on trustpilot :)

I’m going to get mine calibrated at some point via calmet. Urgency is low at the moment though.
 

Offline tautech

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11144 on: May 23, 2018, 07:58:04 pm »
I believe tgzz (or was it tautech?) mentioned earlier that the default is 3V, and that you can Cal at 1/3 scale (1V), but inaccuracy would be 3 times as great at the high end of the scale.  :bullshit:  You would have to bring the displayed number down to read 1V, which I think will also be LOTS of button clicks...  :scared:


mnem
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Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11145 on: May 23, 2018, 07:59:31 pm »
Many thanks for your help. The AC Amps don't have to be calibrated if you have the DCV, DCA and resistance ranges and the ACV all done but the way I read it needs to be done is if it fails the performance testing.

I might, if I feel particularly flush at some point get it done at Calmet if they can do it to 5 digits, it would then demonstrate just how good the tools that I have are  ;) problem is that then I'd have to get all the others re calibrated to reflect the 3478A, if it came back different, does it ever stop  :palm:
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Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11146 on: May 23, 2018, 08:23:01 pm »
Welcome to voltnuttery.

 

Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11147 on: May 23, 2018, 08:31:36 pm »
Haha, your the one who has no faith in his current calibration and is getting it done professionally >:D

You're right though, years ago with analogue meters it was not so important but with the advent of digital everything it seems that we have gone stir crazy on getting everything to match and digits to switch over at the same time etc because we can see things in so much more clarity. Before just viewing just slightly away from dead centre  would make slight differences but no-one really worried so much did they?
« Last Edit: May 23, 2018, 08:44:47 pm by Specmaster »
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Offline Cerebus

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11148 on: May 23, 2018, 08:51:09 pm »
... the only other lab remotely near me is Calmet, who say that can do it but it is not known to how many digits, unless bd139 does as he spoke to them?

To more digits than you've got. Calmet's UKAS accreditation details can be found here https://www.ukas.com/wp-content/uploads/schedule_uploads/00001/0143Calibration%20Multiple.pdf. The limit on their capabilities (for artefact calibrated meters like the HP 3458A) is their sourcing capability for standard quantities like 10 V (0.8ppm k=2) or 10kΩ (3.0 ppm k=2).

For more mundane calibrations their generation capability (i.e. the output of a variable calibrator) for resistance is ~25 ppm, DC voltage ~35ppm, AC voltage ~200-300ppm (all with an expanded uncertainty with k=2 i.e. the standard deviation of any error is 1/2 the stated number). I'm just picking values for middling ranges there, you can see full details in the UKAS accreditation.
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Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11149 on: May 23, 2018, 09:10:43 pm »
... the only other lab remotely near me is Calmet, who say that can do it but it is not known to how many digits, unless bd139 does as he spoke to them?

To more digits than you've got. Calmet's UKAS accreditation details can be found here https://www.ukas.com/wp-content/uploads/schedule_uploads/00001/0143Calibration%20Multiple.pdf. The limit on their capabilities (for artefact calibrated meters like the HP 3458A) is their sourcing capability for standard quantities like 10 V (0.8ppm k=2) or 10kΩ (3.0 ppm k=2).

For more mundane calibrations their generation capability (i.e. the output of a variable calibrator) for resistance is ~25 ppm, DC voltage ~35ppm, AC voltage ~200-300ppm (all with an expanded uncertainty with k=2 i.e. the standard deviation of any error is 1/2 the stated number). I'm just picking values for middling ranges there, you can see full details in the UKAS accreditation.
Thanks, thats a lot more detail than RS provide for their certification details of which are here https://uk.rs-online.com/web/generalDisplay.html?id=aboutRS/our-certifications but they also have UKAS accreditation and yet were unable to calibrate my poor lowly (by today's standards) 3478A.

Yet I have managed it at home without all of their complicated gear, admittedly it might be a few ppm out but certainly near enough for my simple needs. I don't need to have it 100% bang on for fear of being inspected etc as I'm not carrying out a commercial operation of any kind.
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