Test Equipment Anonymous (TEA) group therapy thread

[Andrew_Debbie]

CONTACT CLEANER

So do you have any experience / recommendation for some cleaner from a well know brand, that I could get from Farnell ?

I use Würth Contact Spray to clean the door into the MRI faraday cage.   This was recommended by the manufacturer.   



The door frame is stainless steel. The door has copper fingers.  Both are connected to the cage earth.

Poor contact at the door will put the scanner out of spec for noise.  It can get bad enough to show up on scans.   With the old cage I used to walk around with my old Radio Shack scanner on 127.74MHz and hunt for leaks.




I'm cleaning the floor today.   If you've ever wondered how "they" clean around a 3T magnet . . .




There is MRI safe janitorial equipment.   It is expensive --  ~$1000 for a mop and bucket.    -> http://ketteringsurgical.co.uk/shop/mri/mri-maintenance/dual-bucket-and-mop-system-12808.htm
Broom and dustpan is about £300 --> http://ketteringsurgical.co.uk/shop/mri/mri-maintenance/fiberglass-broom-handle-and-broom-heads-23704.htm

[david77]

I've always got a big can of KWL handy, it's a good alround cleaner for electronics.

Just don't keep it too long or this might happen...

By the looks of it that was a VERY old can, right? Did it explode or corrode?

[Neper]

By the looks of it that was a VERY old can, right? Did it explode or corrode?

It was indeed rather old. I gather it ripped open once the seam was sufficiently weakened by corrosion. But it must have been quite a bang because the shelves in the photo had been leaning against the other side.

I've also had cans of Kontakt 60 getting leaky at the bottom seam and causing an ugly mess, but without any pressure involved. They generally tend to lose pressure over time.

Oh, and let me add another vote for Teslanol. Works nicely. I've also bought a can of the Finnish stuff after it was mentioned here but haven't had an opportunity to try it, yet.

[tautech]

Calling xrunner:
https://www.eevblog.com/forum/projects/any-old-time-ho-model-railroaders-out-there/

[Ice-Tea]

I've been told by a Kontakt Chemie rep to use their stuff in this order: First clean/deox using K60, then wash away with KWL and for delicate contacts use K61 for protecting/lubricating the contacts.

That's exactly what's in the datasheet

[Neper]

In earlier days, I've often used their Tuner 600, initially developed for the gold-plated contacts in drum-type vhf channel selectors of tv sets.

Far less aggressive than K60, no need for subsequent rinsing with WL and it had the great benefit that it could be applied while the the patient was switched on without blowing yourself up.

[m k]

Here CRC and PRF were synonyms for spray cleaners back in the day.

For a Freon era person and after it Kontakt 60 wasn't acceptable, maybe it's different now.
PRF blue is the dry one and it vaporizes shortly.
Can't remember that Kontakt WL was part of a set I was offered close to 30 years ago, not necessary how it actually was.
Kontakt 60 I had stayed around incredible long time and left something behind, that actually was so, those cans lasted quite some time.

It also seems that many times people are using those spray solvents like pressure cleaners.

[dl6lr]

The data connections between the head coil and the scanner computers are optical.   All of the receive electronics are in the head coil.  This is a huge S/N improvement over our old (2006) scanner, where the receivers were in an adjacent room.

There is a certain probability that this coil was partly developed by a good fellow of me. He wrote his thesis about a new head coil he developed at Philips Medical Hamburg (AKA Röntgenmüller).

https://www.wikiwand.com/de/Philips_Medizin_Systeme

[med6753]

CONTACT CLEANER

So do you have any experience / recommendation for some cleaner from a well know brand, that I could get from Farnell ?

I use Würth Contact Spray to clean the door into the MRI faraday cage.   This was recommended by the manufacturer.   


.....snip

I'm curious. Can a person who has perhaps a metal plate in their head or metal hardware to repair a broken arm/leg get an MRI? My gut says no. 

[Specmaster]

Just added another label printer machine to my collection, saw this Brother P-300 SP on the bay of evil, alleged was working fine and then would not power up, well at the price it would have been rude not to I thought. Need something to get on with on my bench instead of radios, which I have a couple to do but at the moment can't be arsed with, so I thought a labeller might be interesting to have a go at. Expecting it any day now 

[Andrew_Debbie]

HP 6235A Fun Fact

While the supply is rated +6V  and +/- 18V maximum,  it can go quite a bit higher with no risk of damage.



Mine will regulate well past 7V and can take the meter off scale high, even under load.

7V out is fantastic.  I can use it to drive things that have an on-board 5V regulator and reverse polarity protection diode.    7805 w/series diode here:
(Sorry about the return of the AN-888S.  I needed two meters)

[THDplusN_bad]

I've been told by a Kontakt Chemie rep to use their stuff in this order: First clean/deox using K60, then wash away with KWL and for delicate contacts use K61 for protecting/lubricating the contacts. I've always got a big can of KWL handy, it's a good alround cleaner for electronics. Do not use on optics!

I have to say I prefer the Caig stuff, especially the D5 in the needle dripper bottle. So much less mess. I've had that small bottle for >5 years now and it is maybe 1/5 empty. Not cheap and not readily available but lasts a long time. The FaderLube is also nice for all kinds of pots.

I can second that advice on "Kontakt Chemie" products. They are a subsidiary of CRC for some time now http://www.kontaktchemie.com/KOC/.
For "simple" switches such as used in car electric or power switches, you may also want to look into https://brunox.swiss/index.php/en/products/turbo-spray
Mind the NSF certification... It's also very useful in the workshop. Turbo Spray and Ballistol in my workshop - never ever tempted to use any WD-40 again! 

Cheers,

THDplusN_okish

[ch_scr]

I've been told by a Kontakt Chemie rep to use their stuff in this order: First clean/deox using K60, then wash away with KWL and for delicate contacts use K61 for protecting/lubricating the contacts. I've always got a big can of KWL handy, it's a good alround cleaner for electronics. Do not use on optics!

I have to say I prefer the Caig stuff, especially the D5 in the needle dripper bottle. So much less mess. I've had that small bottle for >5 years now and it is maybe 1/5 empty. Not cheap and not readily available but lasts a long time. The FaderLube is also nice for all kinds of pots.

I can second that advice on "Kontakt Chemie" products. They are a subsidiary of CRC for some time now http://www.kontaktchemie.com/KOC/.
For "simple" switches such as used in car electric or power switches, you may also want to look into https://brunox.swiss/index.php/en/products/turbo-spray
Mind the NSF certification... It's also very useful in the workshop. Turbo Spray and Ballistol in my workshop - never ever tempted to use any WD-40 again! 

Cheers,

THDplusN_okish

Poor Vince is going to need an Excel sheet to weigh all the Pros and Cons to find the "right" contact cleaner now 

[Robert763]

Interesting cables chosen for the picture of an OWON current clamp 
www.ebay.co.uk/itm/173844935892
Really instills confidence........

[Neomys Sapiens]

CONTACT CLEANER

So do you have any experience / recommendation for some cleaner from a well know brand, that I could get from Farnell ?

I use Würth Contact Spray to clean the door into the MRI faraday cage.   This was recommended by the manufacturer.   


.....snip

I'm curious. Can a person who has perhaps a metal plate in their head or metal hardware to repair a broken arm/leg get an MRI? My gut says no.

So you have ferromagnetic metal in your gut? 

[ch_scr]

Interesting cables chosen for the picture of an OWON current clamp 
www.ebay.co.uk/itm/173844935892
Really instills confidence........

I think someone did a joke he knew his Boss would not understand 

[TERRA Operative]

Meanwhile in Seattle: local radiostation bricks Mazda's car radios:

https://www.seattletimes.com/seattle-news/thanks-to-a-glitch-some-seattle-mazda-drivers-cant-tune-their-radios-away-from-kuow/

  

lol, smells like the satnav tried to do an OTA update with a jpeg of an album cover... 

[mnementh]

   www.ebay.co.uk/itm/173844935892   

Interesting cables chosen for the picture of an OWON current clamp     Really instills confidence........

BWAHAHAHA! That's a instant classic! 

mnem

[Neomys Sapiens]

Another comment on the operation of the DMMCheck is due, I think. I find the method used to select a frequency very clumsy during continued testing. In combination with the fact that there is no indication for the currently active frequency, you are only left the choice between
a.) keeping an instrument at hand to measure frequency
or
b.) switching the DMMCheck On and Off unnecessarely.
I think that an additional switch would be the best solution.

[mnementh]

Meanwhile in Seattle: local radiostation bricks Mazda's car radios:

https://www.seattletimes.com/seattle-news/thanks-to-a-glitch-some-seattle-mazda-drivers-cant-tune-their-radios-away-from-kuow/

  

lol, smells like the satnav tried to do an OTA update with a jpeg of an album cover... 

    https://xkcd.com/327/

So... do we blame the radio station for something randomly borked in their datastream, or the car MFR, who didn't program the FW so it rejected rando "OTA update files" that fail their checksum?

mnem
*toddles off to find a m4 screw the right length*

[Andrew_Debbie]

I'm curious. Can a person who has perhaps a metal plate in their head or metal hardware to repair a broken arm/leg get an MRI? My gut says no.

I am extremely cautious and will not scan someone if there is any doubt about an implant.

Metal can cause distortion or signal loss. Sometimes even a small bit of metal will ruin a scan.   (I've attached an example  -- A tiny bit of Aluminum in a mask noseband caused loss of signal - the front of the head is gone)

Most orthopaedic implants like pins and screws are either MRI safe or MR Conditional.  MR Conditional can be scanned if you follow manufacturer guidance.  Either they aren't ferromagnetic or they aren't going anywhere once the bone has healed.

Aneurism clips are a NO SCAN.  They don't have to be ferromagnetic.   Moving around in a high magnetic field can induce a torque which can be catastrophic.   

Along with the static field there are also rapidly changing magnetic gradients.  The gradients can induce a torque. They can also induce a current in implants which can cause heating.   Something to consider if someone ticks a yes box on the safety screening form.

A scanner uses brief RF pulses ~10kW (127.74MHz for a 3T scanner)   There is a danger of RF burns if you happen to have a conductive loop that is close to resonance.








Source:
http://www.mrisafety.com/TMDL_list.php?mastertable=SafetyInformation&masterkey1=189






 

[tggzzz]

I'm curious. Can a person who has perhaps a metal plate in their head or metal hardware to repair a broken arm/leg get an MRI? My gut says no.

Usually.
https://monib-health.com/en/post/1-can-you-get-an-mri-with-a-metal-implant
https://www.caepv.org/can-you-have-an-mri-scan-with-metal-implants/

I swallowed a gold tooth crown a week before an MRI; the technicians were unconcerned. I was unconcerned because I had gone panning for gold, and recovered it before the scan.

[Robert763]

The Sunset E10 tester arrived today. Seems to work, but the basic datacom cable that all those leads and adaptors connect to is missing    It appears to be unobtainable too, Has a HDI-30 plug on it (was used on some MAC SCSI interfaces). So looks like the E10 won't be much use other than testing coax at 2.048 MHz.

Anyone got an old MAC SCSI lead with a HDI-30 (30 pin square) plug? Maybe I could hack one of those into something usable. 

[Neomys Sapiens]

The Sunset E10 tester arrived today. Seems to work, but the basic datacom cable that all those leads and adaptors connect to is missing    It appears to be unobtainable too, Has a HDI-30 plug on it (was used on some MAC SCSI interfaces). So looks like the E10 won't be much use other than testing coax at 2.048 MHz.

Anyone got an old MAC SCSI lead with a HDI-30 (30 pin square) plug? Maybe I could hack one of those into something usable.

Please send detailed image of connector. I have recently seen a gaggle of related types in a drawer.
Could check next week.

[Neomys Sapiens]

More TEA. Despite trying to downsize and organise, I’m still buying.
I have a very good collection of current clamps and transformers, more than 20. They range from Tek CT2 & P6019 (mA to A HF) through multiple 100 A & 1000 A (AC and AC/DC) to a MA431 rated at  40,000A pulse. However there has been a bit of a “hole” in the tens of mA to tens of A AC/DC range. I felt this recently when investigating a EMC mains filer with high leakage.
So I fixed that last night by a BIN of an albino Fluke i30s AKA LEM HEME PR30.
.
.

I have a PR30 and a PR430 (DC to 30kHz, 40/400A) and there is nothing wrong with them. The PR30 is used frequently even as I have a AM503/A6301.
Tek CT2 is something nice to have!
MA431 is awesome!