Bug Report: FLUKE 233 magical multimeter is clipping through objects again.

@leocurious9919

Жыл бұрын

I thought it was a recording from a 2. camera that he overlaid... until he touched in the the second scene...

Another step on the long road to Signal Path lithography. We know what the chip logo will be.

@benmodel5745

Жыл бұрын

Pooch, definitely

14:16 The sudden horror of a decapitated multimeter head never fails to appall!

Thanks for still doing these vids they are often far too advanced for me but your delivery makes me understand a little more each time. Keep it up!

Great addition to the channel. From microwave to nanowave!

@Peter_S_

Жыл бұрын

DC to Daylight

Fascinating! I've never worked with optics but recently got to see some operating optical clocks. Have you ever thought of doing a teardown and demo of an atomic clock? Watching the PLL lock in a rubidium module might be interesting.

@witeshade

Жыл бұрын

i'm pretty sure he did a bunch of videos about rubidium timing modules 5-6 years ago!

@TrimeshSZ

Жыл бұрын

There isn't much to see, unfortunately - the transmission difference on the Rb cell at resonance is very small, which is why you have to modulate it and use a lock-in amplifier to detect it.

Definitely like the variety of vids! As usual you show way more of the workings of these pieces of equipment than other channels, that makes it always interesting to watch.

The helium reservoir on the ones I’ve seen has a membrane that has increasing helium permeability as it’s temperature is increased. The heat sink band stops the heat conduction along the glass, so that the helium leakage is near zero. Incidentally, if a laser has been sitting too long, the helium pressure may be too high to achieve lasting until the tube has been run for possibly as much as 100-200 hours. And for the benefit of anyone who hasn’t already read a service manual on a helium cadmium laser, the discharge current is typically 100mA or more DC, with significant amounts of capacitance in the power supply. Accidents are likely somewhere between extremely painful and potentially deadly, from muscle contractions or heart stoppage. If you’re really lucky, you’ll only realize your heart stopped when it starts beating again and you just used up one of your nine lives. Or maybe that’s just what happens when voltage jumps without a direct contact with a HV lead.

This might have been the first time I've heard emission line spectra described as "tones". But I get it! I have a H-𝛼 emission line filter in the filter wheel of my CCD camera I use for astrophotography. It produces some very nice images of emission nebula. Turns out there's a lot of hot hydrogen in the Universe!

Beautiful! I have seen a couple of these pop up en eBay, but minus the power supply. So nice to see one up and running!

Another incredible breath of knowledge with a side of nerdgasm 🍻

Big burney lasers always get my attention, never seen this type before. Big Thumbs Up 👍👍

Very cool indeed. It reminds me my studies and specifically the lab time we spent building a HeNe laser "from scratch".

Love it! I've been reading a few books on laser physics so this came at a perfect time.

Helium/Cadmium? Never heard before - thanks! Once upon a time I got a HeNe laser for measuring the angle of a worn out steel blade used in making soft tissue in a paper machine. The blade was about 1 mm in thickness and the edge was worn an polished maybe 0.1 to 0.3 mm size. The laser had 1.5 mm beam, so some of the beam passed on eatch side of the blade, when aligned. At that orientation the worn surface reflected light at an angle, which I calculated by arctan function from the dot on a graph paper. The reason for my angle measurements was that also the machine slightly barrel shaped cylinder wore out unevenly and the blade wear angle variation along the nearly 5 meter length of the blade gave a map of the cylinder wear. Some time later my boss got new glasses, which he found some way wrong. He suspected a mistake in the pupil distance and asked if I could somehow measure it from the lenses. He knew what his pupil distance had been "for ever". I found that both 18:41 the glass surfaces produced a reflection and they matched, and also reflected back to the laser aperture only when at the desired pupil spots. Marking them with ink, it was easy to to measure the distance and confirm his suspicion. He went back to the optician, who was surprised that the distance had been correctly measured without an optician's tool. A "feather to my hat". Some time later I was involved with a test whether the paper dryness could be measured in line with an experimental Water Vapor laser. Despite a good theory, the desired 5 meter distance quickly turned beyond reach. Our test setup was only about 1 meter and already was too challenging. At the time there were commercial infrared based paper web moisture measuring devices, but they required complex mechanisms on two sides of the paper web, source and receiver traveling in a synchronized way. Consequently, they were deemed too cumbersome in use, and also too expensive. That is why the idea of a water vapor laser was tried.

@pariskennard4540

Жыл бұрын

Thank you, this is fascinating!

I got into lasers on a hobby level with some HeNe tubes and not much later with an Argon Ion head and homemade power supply. But those transparent "glass" tube laser are always much nicer to watch ;)

Thats a heck of a laser pointer to keep your cat entertained!!☺☺😎

Nice! Really enjoyed this one!

I would love to see more laser and optics videos!

I have loved lasers since we got to experiment with a very low power HeNe laser when I was in 8th grade (a VERY long time ago). That looks like a very capable spectrometer. I have always been fascinated by how 19th century scientists doing some fairly crude spectroscopy produced results that led us to understand so much about the structure of the atom and, on a different branch of the scientific tree, to the beginnings of quantum mechanics. I encourage you to explore more fundamental science topics!

@lolilollolilol7773

Жыл бұрын

It was very crude indeed, not much different from what Newton did with his prism.

Very illuminating!

0:33 "dumpster find", yea your dumpster is not the same as mine.. for sure.

@Gameboygenius

Жыл бұрын

Dave's (EEVBlog's) dumpster room also has a bunch of good stuff all the time. How do they do it?

@dtiydr

Жыл бұрын

@@Gameboygenius You normally work at a place where there is a lot of high tech companies around you or in the same building where all the companies throw their things at one place where you have access to, and that was (is?) the case with Dave. I don't know where he in the video is (forgot your name) but its no doubt not in the middle of nowhere but high tech companies in the close vicinity or building is my guess where he has access to any dumpster room.

@willthecat3861

Жыл бұрын

@@Gameboygenius Dave finds it (or is given it) first, and it's a "dumpster find." Some people believe 'reality T.V." too.

Very cool and unusual laser, thanks for sharing it with us!

Curious as to what the Optical Power output of the Laser is?

Gotta love seeing the spectral pairs.

Amazing!

Thank you

Awesome topic !....cheers.

Love this video, more lasers please!!!

Really enjoy these photonics videos. 🤌

What a beautiful machine, thank you

Awesome work many thanks 🙏🏼

Great Video Thanks.

I think the connectors are MIL-DTL-5015. On the back of the case, the left most connector looks like insert 22-20, the middle one is 24-5, and the last one is 24-22. Maybe. Is the keying rotated? You can get MIL-DTL-5015 connectors on Mouser, though for whatever reason the pictures of circular connectors are always wrong.

Just brilliant.

Incredibly cool laser and a great explenation. Could you maybe do a breakdown of the power supply? It would be interesting to see how all the current regulation and the controls work.

I remember working with helium cadmium lasers back in the 1970s at Intec corporation. We used them to test certain types of photographic film without exposing the film.

Would be nice to follow-up with a measurement of the narrowband laser spectrum and the coherence length of the laser..

Thanks for another good and informative video! Those Omron hour counters lose their count when the internal battery dies, so they're not always accurate.

Im firing with my lazooor! Nice video!

great -- very interesting video again, never saw a he cd laser in action. I use laser in my profession usually semiconductor, also for spectrum analysis, I have a helium neon laser for experiments and reference -- @the signal path : which spectrometer have you used ? - I myself have a thorlab spectrometer CCS200 (200nm-1000nm) your seem to have a larger range !

Are those cadmium deposits on the working laser inside of the tube meant to be there or was that due to improper shutdown sequence? and how do you know if hasn't negatively affected the mirror on the front of the laser tube?

@Thesignalpath

Жыл бұрын

I don’t think it affects anything as it is not on the mirrors.

The three metal rods that form the structure are made of a highly specialized alloy with extremally low thermal expansion.

Had a rodenstock laser lens calibration machine back then from the scrapyard, luckily it tripped the breaker before anything worse happened.. ^^

@TheSignalPath i completely agree, never take lasers lightly, darkly yes but not lightly. 😉

It threw me off at first seeing the laser spot through the goggles with a rated attenuation of 10^9 at the wavelength being emitted. I'd guess the light seen is not the emitted ~400nm light but instead longer wavelengths generated by fluorescence of the paper.

That was fun.

That is gorgeous all right. Was it out of something or is it some sort of lab optical source?

These lasers are extremely tricky to operate. Each laser head has to married with the power supply. To retune a head to a new power supply you have to run it to heat up properly and then adjust the the cadmium and helium heater to get the correct pressure and gas mix. The filaments burning out are usually due to a current regulation fault in the power supply. ❤

It would be nice if you could disassemble the broken unit. I'm very interested how the helium storage and release mechanism is looking / working. First time seeing something like that for a nobel gas.

@MarkTillotson

Жыл бұрын

No please don't poison yourself with cadmium(!)

@jakubniemczuk

Жыл бұрын

@@MarkTillotson I asked to disassemble the tube, not to eat it. :v

Do you have any thoughts on optical transconductance varistors and their applicability to microwave transmitters?

I might have missed it, but what's the rated input and output power of this unit?

@Thesignalpath

Жыл бұрын

It is rated for up to 60mW optical output power.

Please use some polarizing lens to demonstrate Bell's theorem.

I have a question, when you examine the incoherent light in the chamber with the spectrometer what you see are the spectra lines of helium or you see also spectra lines of cadmium?

@Thesignalpath

Жыл бұрын

I mostly saw the lines of He.

FIX MOAR TEST EQUIPMENT!!! J/k - this is really interesting.

Hi. What spectrometer are you using?

I see people repairing CRTs from vintage TVs. Maybe there is hope for the broken laser. Although cadmium isn't exactly friendly to play with.

@Thesignalpath

Жыл бұрын

With the filament broken, I am not sure if it can be repaired.

@pizzablender

Жыл бұрын

@@Thesignalpath If it is exposed, glassblowing is not that specialized. Though it is a very manual process, and the cadmium is nasty. Plus cleaning/ovenizing and refilling, probably best done befor ethe cadmium is everywhere like it is now.

Could you make video on phase array radar too ?

I had a friend of mine who got killed at home by stepping on a laser cable part of his home laser setup - he was in his 20ies.

Near the start of this video you say that “if you only were to use helium and make a helium laser, you would get wavelengths at 632 nm or so which depends on the helium atomic structure.” I think that the 632 nm wavelength is associated with a helium-neon laser. The light from a He-Ne laser is from some of the neon atoms that radiate at 632 nm. The light is from neon not helium.

@Thesignalpath

Жыл бұрын

Yes, He by itself is not a best gain medium and is often mixed with something else. What I meant to say was the common HeNe laser.

@pizzablender

Жыл бұрын

@@Thesignalpath Laser gain media have special properties. Even more so if one wants some modicum of efficiency. One needs an easy pumping transition, then a quick relaxation to an excited relatively stable level that is not much lower. Stable, so only stimulated emission occurs and no spontaneous. Then, after that stimulated emission, the energy level should drop again quickly and spontaneously. Otherwise, the atom that just "cooled down" would absorb laser light again to get excited. So no, one cannot just use any transmission line in a laser. (Note that these transitions/levels are also achieved through gas mixtures, AFAIR. The levels do not need to be in a single atom.)

Is the helium or cadmium being consumed when the laser is operating?

@Thesignalpath

Жыл бұрын

No, the system is closed. There will be small losses over time. Nothing is perfectly contained.

What were these lasers used for?

@douro20

Жыл бұрын

Laser fluorescence, primarily in confocal microscopy, where they are still in use today.

@NiHaoMike64

Жыл бұрын

@@douro20 Have they been replaced with 445nm diode lasers which nowadays are very common?

@douro20

Жыл бұрын

@@NiHaoMike64 Yes, but from what I understand the multiple lines of a HeCd laser are advantageous for exciting fluorescence in different biological molecules.

@johannglaser

Жыл бұрын

@@douro20 Ah, interesting, thanks!

@johannglaser

Жыл бұрын

@@douro20 At 16:16, there is only one line. Or did I misunderstand your sentence?

So what are these lasers used for ?

As Spock would say…..fascinating 🧐

Brilliant, thanks 👍

Wowsers what dumpster are you looking through?

Can the glass experience a catastrophic failure?

@Thesignalpath

Жыл бұрын

If it is met with a hammer, I suppose.

Where is the the rest body of the multimeter ? :D

@zebo-the-fat

Жыл бұрын

it was a bad meter and had it's head chopped off!

So what makes cd go its own place?

@Thesignalpath

Жыл бұрын

The cavity size of the laser.

@omsingharjit

Жыл бұрын

@@Thesignalpath how , why not it deposit on glass !!

I would've thought that laser was much older than 1996.

The reason you can see the spot with the OD9 goggles is because of the fluorescence wavelengths.

@Thesignalpath

Жыл бұрын

I think so!

👍🙏❤

Very neat! We have a coherent source of light lasing at a specific wavelength. What is this light source used for exactly in it’s time period? I’ve heard of lasers dubbed as a solution looking for a problem…what applications does this particular unit used for?

Not a fan of HeCd lasers... which were developed over 50 years ago. You can see by looking at it: they're very expensive. Supposedly Melles Griot still produces them (or at least sells them)... and some old photolith processes need them. I think newer, more robust, and affordable technologies have almost completely replaced them.

LED luminous coating produces visible light and semiconductor produce UV

I've watched like 1 minute of the video and I'm guessing it's a helium laser that fires up and heats the cadmium enough to get that part of the process started... probably not...but am I close even?