RS's Schedule of Accreditation is here. It would be a lot easier if RS made it clearly available, rather than having to hunt it down via UKAS.
Thank you for this, reading the two it seems that Calmet offer the best calibration of the two, but anyone reading RS's capabilities (claimed) would feel comforted to know that they can achieve high standards in theory.
Sadly though my experience does not reflect this capability and the person who I spoke to said that both he and another colleague had downloaded the 3478A manual and neither of them could get it to accept a calibration and retain it. Its no good having all the big flash and expensive calibration equipment if the staff don't know how to use it and or read manuals because clearly something prevented them from achieving what I've achieved at home.
Also claimed that it was reading around 3v low across all voltage ranges, something that is not now doing as it concurs with my 21 other meters, 2 Fluke 27, 10 Fluke 25, 2 HP 3466A, 1 Philips PM2521, 1 Solarton 7045, 1 Keithley 160 and 4 other less known DMM's so on that basis I'm lost for words.
I have my theory's on this but perhaps its best not airing them on a public forum.
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
I could send you my Valhalla AC Calbrator if you like? About $3-400 each way should cover the postage
Hmm it might as cheap to come visit you down under and make a holiday of it I reckon
For that kind of money it must be the motherfucker of all boatanchors jeez.
There needs to be a separate category for some of the big calibrators and voltage standards.... Gould paper recorders can go in it too.... something like battleship anchors? Mind you, even small boat anchors can cover up to pretty hefty items once they're covered in mud. I've nearly bust my farting clapper a few times.
I'm actually developing muscles I'd forgotten I had hoofing test equipment on and off my bench and arranging things. Only little muscles, knots in string stylee.
It's only 4RU high but 500mm deep
@Beanflying , when will we start getting some teardowns...
Well, my Ohmless 3455A turned up today. I'm cleaning off the layer of sticky orange goop covering the front panel, and all the buttons, before doing anything else. I's not a very heavy box, but it's 21" deep. I think this is going to necessitate yet another re-arrange of my bench.
Well, my Ohmless 3455A turned up today. I'm cleaning off the layer of sticky orange goop covering the front panel, and all the buttons, before doing anything else. I's not a very heavy box, but it's 21" deep. I think this is going to necessitate yet another re-arrange of my bench.
German tank maintenance? Do you have a Tiger in your lab you're not telling us about?
... 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.
Dude... reading that made my testicles shrink up like weapons-grade blue balls. In fact, I think one of them may have jumped back inside and "un-descended".
mnem
MEDIC!!!
German tank maintenance? Do you have a Tiger in your lab you're not telling us about?
I wish I did! I've spent the last ten years making scale models of armour, Tigers included, and I'm a stickler for accuracy. I suppose it's unsurprising that once I got into electronics I'd gravitate to TEA in short order. Weirdly, both Silicon Valley and the British tech industry owe their existence to WW2, so having a handle on the history of that period has helped me get my head around the story of how things have developed since then. My understanding is up to about the early eighties at best, I reckon, I'm trying to give myself a better grounding in the basics before diving into MCU's and more complicated stuff.
It's only 4RU high but 500mm deep
...aaand my testicles just came back with an audible *POP!*
mnem
SCHWANNNG!!!
Well, my Ohmless 3455A turned up today. I'm cleaning off the layer of sticky orange goop covering the front panel, and all the buttons, before doing anything else. I's not a very heavy box, but it's 21" deep. I think this is going to necessitate yet another re-arrange of my bench.
German tank maintenance? Do you have a Tiger in your lab you're not telling us about?
Strangely, that 3455 does nothing for me. Not even a little tingle.
I too am more curious about the Panzer Tech on the shelf; I have had my hands inside a couple M4s as a youth, but mostly cleaning parts and whatever they needed a young skinny kid for. I hung with the club just enough to realize how weird the the powertrain was; then I joined my local Fire Dept. and quickly ran out of free time. Radial power in a bulldozer never did make any sense to me; made me glad to get back to passenger vehicles you could just weld whatever V8 you liked into.
mnem
Bulldozer chic!
From what I've seen online (haven't opened it yet) the insides of the 3455A may well induce some wood.
Some great photos in those Volker Ruff books, plus all the necessary plans to build a Fries 16T gantry crane, should the need ever arise (?). I think the range of engines (and guns) they managed to shoe-horn into the Sherman is what it made it such a success. The Chrysler Multibank from the M4A4 has to be my favourite, even more than the radial. Five V8's on a common crank, genius!
From what I've seen online (haven't opened it yet) the insides of the 3455A may well induce some wood.
Some great photos in those Volker Ruff books, plus all the necessary plans to build a Fries 16T gantry crane, should the need ever arise (?). I think the range of engines (and guns) they managed to shoe-horn into the Sherman is what it made it such a success. The Chrysler Multibank from the M4A4 has to be my favourite, even more than the radial. Five V8's on a common crank, genius!
Close - it was five inline sixes geared together. Definitely a pretty impressive piece of machinery!
-Pat
Close, but no cigar, thanks Pat. I knew they were engines! I have a vague memory of making the same mistake before. Actually, I have a vague memory in general.
Close, but no cigar, thanks Pat. I knew they were engines! I have a vague memory of making the same mistake before. Actually, I have a vague memory in general.
Mine is normally like that, too, but I happened to have seen this particular powerplant recently during my net wanderings, so it was somewhat fresh in my otherwise addled brain. Wartime needs certainly made for some novel engine designs.
-Pat
Well, my Ohmless 3455A turned up today. I'm cleaning off the layer of sticky orange goop covering the front panel, and all the buttons, before doing anything else. I's not a very heavy box, but it's 21" deep. I think this is going to necessitate yet another re-arrange of my bench.
That's why I quickly started to hunt down a 3478A as its only 14" deep and half the width and has all the options built in as standard. I'm chuffed as fuck with mine now I have her calibrated at last. If you get all options plugged into the 3455A it will weigh a bloody ton so make sure have plenty of support strength in whatever you put it on.
From mobile device so predictive text might have struck again [emoji83]
The 3478A is on the sweet spot between boringly innaccurate and voltnut crazy. It’s just right
The 3478A is on the sweet spot between boringly innaccurate and voltnut crazy. It’s just right
Yep, bang on there, even now the last digit changing about can be a distraction at times, imagine if you had 2 or 3 changing [emoji48]
From mobile device so predictive text might have struck again [emoji83]
Time to get back to TEA this accurate bending and soldering of wire is doing me in
I remember now why my 8x8x8 kit is still in kit form
You have more patience than me with that LED cube
Getting seriously annoyed. Won that Heathkit AC VM 7 days ago and it was send via Hermes on Monday which to be honest was very late by the seller. Tracking is stuck at "We're expecting your parcel" since then. FFS. £2 more and it would have been here on Tuesday with UPS but cheap fuckers will only deal with Hermes for some crazy reason.
You have more patience than me with that LED cube
Getting seriously annoyed. Won that Heathkit AC VM 7 days ago and it was send via Hermes on Monday which to be honest was very late by the seller. Tracking is stuck at "We're expecting your parcel" since then. FFS. £2 more and it would have been here on Tuesday with UPS but cheap fuckers will only deal with Hermes for some crazy reason.
I know that feeling, I've sat looking at similar screens many times myself. Sometimes though it doesn't get updated at all. I'd check with Hermes just to make sure that it is correct. Then I'd be creating hell with the seller, tell him you needed it by a certain date and now it's to late, threaten to open a dispute via Ebay, if nothing else you might get a refund.
From mobile device so predictive text might have struck again [emoji83]
The 3478A is on the sweet spot between boringly innaccurate and voltnut crazy. It’s just right
Yep, bang on there, even now the last digit changing about can be a distraction at times, imagine if you had 2 or 3 changing [emoji48]
From mobile device so predictive text might have struck again [emoji83]
Now that you've got the 3478A where you want it I would advise you to buy a 2nd AD584. Why? As a cross check. If something starts drifting you'll know right away which device is going south. That's what I've done here. And I document the results. My most accurate DMM is a Fluke 8800A. Here's the chart of how it compares to each AD584. I'll know right away if there's an issue.
1st AD584 8800A
2.50066 2.5007
4.99794 4.9979
7.50011 7.5002
9.99691 9.9970
2nd AD584 8800A
2.49937 2.4994
5.00030 5.0003
7.50042 7.5004
10.00096 10.0010