Test Equipment Anonymous (TEA) group therapy thread

[neo]

I just calibrated my first multimeter, a Fairchild 7050, it is a nixie tube multimeter ^{_{(i will post pictures tomorrow)}} though mine may as well just be a meter. It gives you volts and ohms but if you try to calibrate both the second half throws the first off and only has two 10 turn pots to adjust i. As far as a volt meter goes it is now as accurate _{(as i think)} my fluke 8000A is and much prettier.

[madires]

Calibration is something different. You've adjusted the multimeter. Calibration is the process of compairing the measurements of your multimeter with a calibration standard. The results tell you how much your multimeter drifts over time.

[Red Squirrel]

I keep getting urges to buy test gear that I don't really need, my electronics hobby is quite small so it's hard to justify spending tons of money (oh, I still do... lol).  But I think I may have possibly found a need to buy a thermal imaging camera.

I've been playing with stuff involving mosfets and power electronics, and my current test method to see if a part is getting hot involves my finger.

The other day I managed to imprint a burn mark in my finger the shape of a resistor. I think that may be a good case to buy a thermal imaging camera.    The tip of a TO-220 package will leave a nice mark too.    I have to admit I'm surprised at how resilient a typical mosfet is.  Accidentally shorted them out more times than I'd like to admit. 

Actually I also need to invest in a bench supply that can do current limiting and variable voltage.  Just using an ATX PSU now.  I keep putting it off as I want to learn more about power electronics and build my own, but I should probably still get a proper one to at least start off with.  So another item to add to the shopping cart. 

[PA0PBZ]

The other day I managed to imprint a burn mark in my finger the shape of a resistor.

A bit like the old dram chips that were used in a lot of 'personal computers' like the TRS-80 and such. It was very easy to find the defective chip but not so easy to get the manufacturers logo from your finger afterwards 

[neo]

Calibration is something different. You've adjusted the multimeter. Calibration is the process of compairing the measurements of your multimeter with a calibration standard. The results tell you how much your multimeter drifts over time.

The standard here is my fluke 8000A. I never said it was a good calibration but it does technically qualify i think. The fluke is the multimeter i defer to whenever something seems weird and is more or less the standard in my 'lab' at least until i get a proper calibrated standard.

[alm]

It does not help that many vendors, for example Keysight, will adjust any equipment you send in for calibration if possible and found to be out of spec (see attachment). Calibration without adjustments is something you would have to specifically request. So I think you can consider that distinction a lost cause.

A calibration does not have to be traceable to a standards lab. You can calibrate everything to your house standard to keep measurements consistent across the company without necessarily being traceable. This is for example very common for mass production: products get calibrated by some production tester using procedures that may not qualify as traceable calibration. Which is why you often pay extra to get a calibration certificate with a new piece of equipment.

[tautech]

It does not help that many vendors, for example Keysight, will adjust any equipment you send in for calibration if possible and found to be out of spec (see attachment). Calibration without adjustments is something you would have to specifically request. So I think you can consider that distinction a lost cause.

A calibration does not have to be traceable to a standards lab. You can calibrate everything to your house standard to keep measurements consistent across the company without necessarily being traceable. This is for example very common for mass production: products get calibrated by some production tester using procedures that may not qualify as traceable calibration. Which is why you often pay extra to get a calibration certificate with a new piece of equipment.

Why could that be, well I mean that new equipment has been verified as meeting published spec before it's packaged for delivery by some non-traceable standard ? 
You can be sure in production of test equipment that some buyer will use for complex design or precision measurement that the manufacturer will have a record of such Cal and to not make it freely available to the buyer is just penny pinching meanness.

Cal labs on receiving gear for checks first verify the equipment meets spec or not and then proceed with adjustments (calibration) if their customer has asked for them.
One needs to distinguish between verification, calibration and some untraceable adjustment as they all mean different things.

[madires]

If you're required to have a NIST or whatever traceable calibration, the correct procedure for an adjustment would be to calibrate the measurement device first, then to adjust it, and to calibrate it again afterwards. If you keep your measurement devices consistent with an internal standard, it's an adjustment. You adjust the devices to match your standard. Calibration is meant to track the accuracy and drift of a device over time. Performing an adjustment without the calibration before and after breaks the tracking chain. It's totally fine to just adjust your DMM or what have you from time to time. But you don't get the tracking provided by the calibration.

[alm]

Cal labs on receiving gear for checks first verify the equipment meets spec or not and then proceed with adjustments (calibration) if their customer has asked for them.

Or in the case of Keysight, adjusts them unless their customer has asked them not to.

If you're required to have a NIST or whatever traceable calibration, the correct procedure for an adjustment would be to calibrate the measurement device first, then to adjust it, and to calibrate it again afterwards.

Well yes, NIST traceable calibration must be traceable to NIST. And you can easily get traceable calibration without data from the likes of Fluke. Very useful for the crowd that just wants their rubber stamp for ISO9000. But the fact that we use the term traceable calibration implies that there is such a thing as non-traceable calibration. How would you define that?

If you keep your measurement devices consistent with an internal standard, it's an adjustment. You adjust the devices to match your standard. Calibration is meant to track the accuracy and drift of a device over time. Performing an adjustment without the calibration before and after breaks the tracking chain. It's totally fine to just adjust your DMM or what have you from time to time. But you don't get the tracking provided by the calibration.

You can track accuracy and drift relative to your internal standard. The fact that your internal standard may not be traceable to NIST breaks the traceability chain. So it is clearly not a traceable calibration. But is it not a non-traceable calibration?

Let's see how Fluke defines it in "Calibration: Philosophy in Practice (2nd edition)", page 3-6:

Calibration: A set of operations, performed in accordance with a definite, documented procedure, that compares the measurements performed by an instrument to those made by a more accurate instrument or standard, for the purpose of detecting and reporting, or eliminating by adjustment, errors in the instrument tested.

Nothing about traceability. And indicating that calibration may either report the data or adjust the instrument (I imagine that is a non-exclusive or).

[madires]

Well yes, NIST traceable calibration must be traceable to NIST. And you can easily get traceable calibration without data from the likes of Fluke. Very useful for the crowd that just wants their rubber stamp for ISO9000. But the fact that we use the term traceable calibration implies that there is such a thing as non-traceable calibration. How would you define that?

When an internal standard (not NIST or whatever traceable) is used for calibration. The problem with that is your 1V might be 1.12345V based on the NIST standard and someone else's 1V could be 0.98765V.

You can track accuracy and drift relative to your internal standard. The fact that your internal standard may not be traceable to NIST breaks the traceability chain. So it is clearly not a traceable calibration. But is it not a non-traceable calibration?

Same as above. In your local view everything looks fine while your standard drifts.

Let's see how Fluke defines it in "Calibration: Philosophy in Practice (2nd edition)", page 3-6:

Calibration: A set of operations, performed in accordance with a definite, documented procedure, that compares the measurements performed by an instrument to those made by a more accurate instrument or standard, for the purpose of detecting and reporting, or eliminating by adjustment, errors in the instrument tested.

Nothing about traceability. And indicating that calibration may either report the data or adjust the instrument (I imagine that is a non-exclusive or).

The more accurate instrument or standard could be an internal, but also a traceable one. In most cases EEs would expect a traceable one. Actually calibration is the prerequisite for verification and adjustment. You compare the measurements with your standard or more accurate instrument. Based on the instrument's specs (our your requirements) you verify if it's within specs or not. If not, you'll adjust the instrument.

[neo]

I got the HP 5340A  frequency counter

It counted to 55 MHz before it wouldn't read, i assume due to signal level. But i can't go much higher anyways.
 
I took the top off, it does have option 001

My nixie tube multimeter now has company

HELP! It worked, until i took the top off to look inside put it back on and then put the unit on the shelf, now it just reads 0000.0000. Did i break it already?    I didn't touch anything inside.

[AF6LJ]

Nice;
Just remember those counters that are old enough to have grandchildren are very temperamental.
My 5245 has an interment switch on the real panel that needs wiggling once and a while.

[neo]

Fellow TEA partakers may be please to know i found a suitable replacement knob in my scrap drawer. Nowhere near original but it does look nice and not out of place. In further news its still locked into whatever mode and will not count, my cheese is slipping ever further off its cracker over that.

[xrunner]

Fellow TEA partakers may be please to know i found a suitable replacement knob in my scrap drawer. Nowhere near original but it does look nice and not out of place.

I like to hear good news about knobs! 

[GreyWoolfe]

Speaking if knobs, I remember back in my mispent youth, a busty young lady having a t-shirt with text prominently placed that said-I am perfectly well adjusted, leave my knobs alone.

[mtdoc]

Uh oh - I just purchased my first Nixie tube test equipment. I've been on the lookout for a reasonably priced, good condition and small Nixie tube counter. Not because I need a counter - I have a perfectly functional Tek CM251 - but because Nixie tube counters look cool.  Is that so wrong? Am I in danger od succumbing to Nixie Tube Derangement Disorder?

[neo]

Uh oh - I just purchased my first Nixie tube test equipment. I've been on the lookout for a reasonably priced, good condition and small Nixie tube counter. Not because I need a counter - I have a perfectly functional Tek CM251 - but because Nixie tube counters look cool.  Is that so wrong? Am I in danger od succumbing to Nixie Tube Derangement Disorder?

Quick! Give it here before you are too horribly infected by a love of nixes to be saved! 

[xrunner]

Not because I need a counter - ...

Good attitude!

I have a perfectly functional Tek CM251 - but because Nixie tube counters look cool.  Is that so wrong?

If that's wrong I don't wanna be right. 

Am I in danger of succumbing to Nixie Tube Derangement Disorder

Yes. Hell yes. It ain't so bad enjoy the ride.

[Berni]

I don't have any equipment with nixies in it, but this sure makes me want to get some- But i already have my eye on some gear that went up for auction on ebay.... To my defense the said gear has a HP badge.

[mtdoc]

Thanks for the reassurance all. It's just what I needed - a TEA sanity check and group therapy session! 

[Cubdriver]

Uh oh - I just purchased my first Nixie tube test equipment. I've been on the lookout for a reasonably priced, good condition and small Nixie tube counter. Not because I need a counter - I have a perfectly functional Tek CM251 - but because Nixie tube counters look cool.  Is that so wrong? Am I in danger od succumbing to Nixie Tube Derangement Disorder?

Your two questions answered in order. 

1) No, it is not wrong.
2) No worries, you're not in danger of succumbing.  You already have.  It's an insidious affliction.  Stick a fork in yourself, you're done.   

Other nixie equipped gear will begin to show up on your doorstep.  Embrace it.  Welcome it.  Nurture it.  You've begun the long but fun slide down the slippery slope.

Welcome to the orange glowie side.   

-Pat

(Nixie tube DVMs look cool, too.    )

[neo]

Uh oh - I just purchased my first Nixie tube test equipment. I've been on the lookout for a reasonably priced, good condition and small Nixie tube counter. Not because I need a counter - I have a perfectly functional Tek CM251 - but because Nixie tube counters look cool.  Is that so wrong? Am I in danger od succumbing to Nixie Tube Derangement Disorder?

Your two questions answered in order. 

1) No, it is not wrong.
2) No worries, you're not in danger of succumbing.  You already have.  It's an insidious affliction.  Stick a fork in yourself, you're done.   

Other nixie equipped gear will begin to show up on your doorstep.  Embrace it.  Welcome it.  Nurture it.  You've begun the long but fun slide down the slippery slope.

Welcome to the orange glowie side.   

-Pat

(Nixie tube DVMs look cool, too.    )

Cooler even than a nixie tube DVM is one with a fresh calibration fixing other nixie tube gear!

[tggzzz]

Uh oh - I just purchased my first Nixie tube test equipment. I've been on the lookout for a reasonably priced, good condition and small Nixie tube counter. Not because I need a counter - I have a perfectly functional Tek CM251 - but because Nixie tube counters look cool.  Is that so wrong? Am I in danger od succumbing to Nixie Tube Derangement Disorder?

Welcome to the orange glowie side.

Neither forget nor neglect the other orange glowie displays: Panaplex.

They are remarkably soothing and restful to watch. Every home should have some.

[Cubdriver]

Uh oh - I just purchased my first Nixie tube test equipment. I've been on the lookout for a reasonably priced, good condition and small Nixie tube counter. Not because I need a counter - I have a perfectly functional Tek CM251 - but because Nixie tube counters look cool.  Is that so wrong? Am I in danger od succumbing to Nixie Tube Derangement Disorder?

Welcome to the orange glowie side.

Neither forget nor neglect the other orange glowie displays: Panaplex.

They are remarkably soothing and restful to watch. Every home should have some.

Ahh yes - a very valid point.  Panaplex - the other neon crack.

-Pat

[guido]

double dose