I suspect that the heavy cases on the meters had a lot more to do with protecting the instrument than with protecting the operator. That kind of thinking didn't really become common until decades after those meters were built... Fascinating stuff. Thanks Fran!
@@rudolphguarnacci197 Well, that's my own made-up term. Some people make sculptures out of old electronics and old mechanical gear - which is what I mean.
I used to live near the UK National Physical Laboratory. They luminised instruments during WWII, and also were the national centre for radium sources for medical treatment. About 20 years ago that area of the site was demolished and given over to housing. They had to dig out about 6 feet of earth, then put down an impermeable membrane because of the contamination.
Awesome vid Fran, love these retro videos. According to a Department of Commerce Information Circular from 1930, the paint might contain "from 0.7 to 3 and even 4 milligrams of radium element to 100 grams of zinc sulfide.
The AN/PDR-27. I repaired so many of them while working as a technician for the US Government. I remember the Purple Rod used for testing them. Calibrating them behind lead panels was always scary business.
Wow! A real radium dial. Those are so wonderful. Dad's old radio had one... The one that sat less than a foot from his head in the headboard cabinet... Wow.
Even if you have a gamma/ x-ray counter that is not directly sensitive to alpha/beta you'll pick up a little x-ray 'bremsstrahlung' from the alpha/beta particles impinging on the window of the counter.
I had one of those in high school! As I recall, it was 0 to 50 VDC ..it glowed dimly all night. It was connected to my homemade 12 volt selenium solar cell panel. Old orange " carnival glass" was slightly radioactive. We did radiographs with a 1930s orange plate and Tri-X pan sheet film in physics class. This was back in the mid '70s... I like those old school analog meters..I have a few old ones, but most " evaporated" over the years... Another cool video of old school stuff .
In the suburban Philadelphia area in a town called Lansdowne a professor processed Radium in his basement back years ago. The site became a major hazardous waste superfund cleanup site. I grew up about 1/4 mile away. The professor and many of his family have died of cancer.
The evolution of a star. The only stage of a star that doesn't emit any significant light or energy is a black dwarf, and the universe isn't old enough for black dwarfs to exist for another several dozen billion years.
We're 'dust in the wind' but the atoms of our dust was blown on the winds of novas before it came to be reborn as a planet that gave birth to us. The universe is awesome.
Hi Fran, 40yrs ago I watched someone restore those meters !! It's a real pain in the A-- !!! Because you need LOT'S of lead shielding and a positive pressure air mask !! The guy worked at Oak Ridge !
These old instruments are works of art. One thinks to be able to recognize the quality by the care of the production. At that time, the appearance of an instrument was still very important.
Yes. Analog displays don‘t need to be read. They only need to be looked at. When I was young I had a beetle, 80 km/h (50mph) was reached when the pointer was up. To read a watch is way easier with an analog one, e.g. showing that it‘s closed to 12:00. 11:49 on a digital display has to be read carefully....
Thanks! I was aware of this aspect of the two dials on my vintage US military short wave radio Collins R-390A/URR but had not found the explanation of it yet. I now get why these dials are taken out if the crystal shielding is damaged.
That's pretty cool. It seems like those would actually be fairly safe to use in a project. I'd probably use one in a home made Geiger counter just because it would amuse me.
I still have the Baby Ben alarm clock I bought in 1972. The phosphor has been nuked off over the years so there's is very little glow when hit with bright light then put in darkness. However, it still scintillates when your eyes get dark adapted and you can see the little sparkles when you look through a magnifier. We used to do this in physics class in the 1960's with an alpha source in a tube with attached magnifier. Later, the alpha source was taken away by school officials, but we still was playing with the spilled mercury found in the windowsill that oozed up from the woodwork that a student spilled several years before. Today, if a cracked old mercury thermometer is found in one of the old school cabinets, it is red alert!
I used to live near the National Physical Laboratory in Twickenham in the UK. They used to luminise instruments there for aircraft during WWII and after. They also were the supplier of radium for medical purposes. Later they wanted to build houses on that part of the site, they had to dig out to 2 metres deep and seal the land.
That thought about how vintage tech has a lot of radium in it triggered my memory about the story of The Radioactive Boy Scout who managed to collect so much of in in his small shed that it was eventually declared a hazardous radioactive site and the cops had to call in the EPA to clean it up. His radioactive source wasn’t from vintage stuff though.. it was harvested from pilfered smoke alarms lol. What an idiot.
David Hahn built a fast breeder reactor, with americium-241 from 200 smoke detectors, Uranium from Czechoslovakia, Radium from old clocks and the mantles 1950's lanterns, and Lithium from batteries. He died aged 39 due to 'alcohol poisoning'. Taylor Wilson also built a reactor but his was a Fusion reactor, he is still inventing new things.
@DARK APPERITION a pile reactor, which is exactly what it sounds like, also his sources were very widespread, i read he had an extensive collection of radium paint and old clocks in his collection as well as other stuff, he was said to have collected anything radioactive.
He had lazy parents that couldn't be bothered with what their son was doing. When hos mother found out she was more worried about herself then her son.
There is an article I found that does mention specifics and goes into detail about the amount of radium in paint and goes into detail about the composition of them
My Grandfather, I'm 62 btw, had a watch that glowed in the dark, but only the 12,3,6 and 9 had little rocks of yellow embedded in the points and the hands glowed brightly as they went by the rocks, and slowly dimmed as they were away from the rocks. He said he got it in Egypt, and that the rocks were Uranium, and the hands had some Zinc paste on them. The hands glowed a blue color and the 4 points a greenish light not as bright as the hands. Near the 3, there was a moon that changed size for the waxing and waning of the moon, and it glowed as well But I can't remember the color maybe a sort of yellow, there was a picture of the man in the moon or something like that on it. He did this trick where he held his watch up to another watch that had 'normal' radium paint on it, and the other watch would glow really brightly.
Crikey, I used to fix clocks when I was young, lots of them had dials & hands which “glowed”, but I’ll never know if any were *proper* radium ones... oh just remembered about the box of old panel meters stashed under my bench...might be time to get a geiger counter :-)
If you do not have a radiation detector, it is probably safest to assume that any "glow in the dark"-looking paint on older clocks or instruments will contain radium, the use did decline in the latter half of the 1900s, when alternatives became more common, but I wouldn't trust anything before 1970 at the earliest without testing it first(this might depend on where in the world you live, of course) The primary risk is probably not from exposure to the radiation of the dial and hands, but rather ingesting or breathing in the dust that might have collected inside or come detached during the work, so taking precaution against dust is probably best if there is any doubt.
Many years ago, my parents had some green glass bowls which turned out to be a bit radioactive. It seems they used to use uranium compounds to get the nice colour!
I was told by My Jeweler that to some of the early watches and meters used polonium instead of radium because it was less expensive also I have a Korean war-era military Jeep (m38a1) and the speedo is radium lettered and still glows brightly to this day.
Excellent video! Was literally thinking 'that's lead crystal' just as you said it... It occurs to me the dimness may also be down to radium decay, as well as phosphor degradation., but I dunno what its half-life is.
@@alankingvideo Wow. Guess not then. Does that mean the old-style pure radium lume with no phosphor is still as bright as when it was applied? I thought all old radium dials were dim nowadays.
Trump's Tiny Hands From when I looked into this about 20 years ago, it became apparent that the high radium content products were pretty much all identified years ago and disposed of in landfill. It was widely recognised in the 1960 that these items were very dangerous if fragments were inhaled. So we are left with WW1 compasses with radium/ phosphor paint added to the inside of the glass. Watch dials and meters. No toys or pots of paint. Unless someone knows differently. However I dread to think what’s under the old wallpaper in some houses, painting stars and moons on children’s walls was pretty popular.
Very cool! I don't suppose you would consider parting with a few old meters? i need 3 for my transmitter 100ma full deflection or less not picky. I could make 50 ma work too. The ones i have are old and crappy, they stick sometimes and are not the same shape and size. Yeah i could get new ones but they're new, just a thought. I forgot about the haul from the uni years back....makes me think i've been watching you for quite a while now time does in fact fly by.
Weston Meters were made in the UK and USA by Sangamo Weston, and the differences between the two are very minor but they have different model numbers. Some later models were made by other manufacturers under licence. The US company was founded in 1888 Springfield Illinois as a manufacturer of electrical measuring instruments with a factory in Newark NJ, with the UK company following on in Enfield Middlesex a year later. In 1954 the US company was bought out by Daystrom, then in 1962 Schlumberger took over Daystrom. In 1974 the Newark plant was shut down. In 1987 there were investigations going on over contamination of the surrounding land. Sangamo manufactured PCB-containing electrical capacitors there during 1955-74. Sangamo notified the US Environmental Protection Agency of its disposal of approximately 38,700 cubic yards of PCB waste on its plant site and an undetermined amount in seven satellite dumps, all in the Twelve-Mile Creek Basin. Solid, sludge, and liquid wastes were stored or disposed of in piles, landfills, and impoundments. How nice! Since then Sangamo-Weston has removed over 17,000 cubic yards of waste from past disposal areas on and off the plant property. How sad it should all end this way - I'm sure Edward would be turning in his grave if he knew.
A great little video. Imagine all those people who were woken by alarm clocks which were dosing them in radiation all night. I still have my 1970s TIMEX childs watch I wore, with its glow in the dark hands and hour markers. I'm guessing it may still click a little, although it had a thickish glass front.
Cool video, Fran! That said, the part I immediately went back and played again was the closing credits. What a fantastic groove! Is that on a record somewhere?
Also don't forget that the radium itself decays; the isotope with the longest halftime is 1600 years, but the runner-up is only 5.75 years. After a few decades quite a bit of radium may be gone.
The longer the half life, the less radiation it puts out, and the less it will glow. With a half-life of 1600 years in it's most stable form, it is no longer nearly as dangerous, but will also no longer glow enough to be useful. It will take a long time for most of the radium to decay to that state, though.
In the older meters & such, we don't know that they isolated for shorter half-life isotopes. I know I've seen WW2 era meters (almost 80yrs) with dead phosphors that are still hot as heck. Too bad Geiger counters aren't cheaper to have on the average tinkerer's workbench.
@@rich1051414 Actually, the main issue with radium paint is not radium decay-with a 1600 year half-life, the decay is not important in the short-term. HOWEVER, as Fran noted, the phosphors in the paint DO deteriorate. The radiation itself does that, and moisture speeds the process up. Of course, time is a major factor as well. Some alarm clocks from 1968(which was pretty much the last year radium was used in them) will still have a faint glow even after being in the dark for a long period of time, even though they are not too well sealed. The older ones generally have ZERO glow(except under UV light). Fran's meters are way older, but due to they being totally sealed, the faint glow still remains.
@@ordinaryaverageguy76 It does not matter much:radium 226(which was the primary isotope used) has a 1600 year half-life. So the meters can still be quite hot with totally dead phosphors.
I've seen a lot of regular, panel meters at the surplus places I used to go to, but I've never seen a radium dial version. (or if I did, it was when I was young and didn't realize it.) Sadly, they are all out of business now. I should have taken every panel meter the last guy had, but I didn't. (but I've still got quite a few, and my dad has some as well)
I love radium dials. I know "radioactivity is bad" and stuff… I'd probably wouldn't leave it in my pocket but a watch is fine and you could actually see it in the dark as opposed to whatever they use in watches now. Cause that new stuff doesn't glow what so ever.
Yes, Fran. More like this. Ancient electronics porn. The music at the end is genius. I could see it getting old at some point, but right now, it's great.
Be careful not to open or break the glass/celluloid cover on old clocks and watches. Inhaling or ingesting the dust from that paint is lethal. I got a ww2 pocket watch recently, and didn't even think about radium until I'd had the back off and looked inside... 😓😵😱
I remember back in the 1950s you could buy tins of Humbrol luminous paint and as far as I know it was radioactive. The withdrew it in the 1960s because kids used suck the brushes after painting here glow in the dark model skeleton kits.
Beautiful meters Fran! God I love vintage meters. Doesn't the inverse square law only apply to an isotropic radiator? Surely a highly collimated beam doesn't behave this way. Unless I'm wrong of course. Haha. Thank you for the fun and VERY interesting vids Fran ~{:-]
right? I noticed that too after seeing the second cable going to the little tube but thought maybe like it's some sort of two option fancy detector wand....geiger-mueller? [edit] 5:50 oh neat :D
At th-cam.com/video/DWM5MVmHZUM/w-d-xo.html you can see that it is not or not completely covering the gamma detector. The lid for the particle detector tube is to thin to shield gamma radiation.
@@tomnwoo when measuring Gamma, the cover is closed. You only open it to read Alpha and Beta. With the cover closed, the large tube is used for Gamma on the lower ranges, and the smaller tube is used on the higher ranges.
Radium emits a weak 186 keV gamma but it's daughter's have much higher and more penetrating Gamma Ray's. Namely Lead ²¹⁴ and Bismuth ²¹⁴ this was from HPS.org As you know, both 214Bi and 214Pb emit measurable gamma rays, and both can be useful in the indirect determination of 226Ra, a precursor in the decay chain that produces the lead and bismuth progeny. The 214Pb emits lower-energy photons than does the 214Bi, the three most abundant gamma rays from the lead being at 242 keV (7.43 percent), 295 keV (19.3 percent), and 352 keV (37.6 percent). The dominant gamma rays from 214Bi are more in number and higher in energy than the lead gamma rays; the range of useful energies is from about 600 keV to about 2.5 MeV. The bismuth gamma ray of highest yield is at 609 keV (46.1 percent); there is a gamma ray at 1.12 MeV (15.1 percent) and one at 1.765 MeV (15.4 percent). The others have individual yields no higher than about 5 percent.
They wouldn't present a serious risk by being opened given the comparatively limited radioactivity of radium paint, but even so, I wouldn't open them just from the point of preservation.
A lot of meters are painted with things other than Radium, like mesothorium, which is insanely radioactive, with a half-life of about 6 years. So it's likely those dials, if they are 60 years old, will be down to about 2^-10 of their initial radioactivity, or just one part per thousand of the original activity!
There is one thing you didn't mention. What were these gauges used for? There is no indication of measurement on them. Just a graduate from 0 to 100. Amps? Watts? Voltage? Temperature? The angle of the dangle? What?
Um, when did radium exit the retail sphere? I'm sure my first wristwatch in the Sixties glowed for hours after eliminating any light source. Also, no need to capitalise the elements, folks, unless you're capitalising the first letter of every word in a sentence for... I don't know what for.
@@philt4346 radium started being phased out in the 1960s, IIRC. Pocket watches were first to remove it, with wrist watches a bit later. Table clocks(alarm clocks mostly) were available until the late 60's(1968)?. Westclox made vast quantities of Big Ben & Baby Ben clocks with Radium dials/hands(many other companies did so as well).
I DO NOT think these contain Ra-226. These were probably re-lumed or never had radium. Not all old instruments contain radium, military or not. For military instruments, if the paint isn't tan or doesn't look "burnt", it's probably not radium. I would do a timed count, for about 10 minutes: One with the meters as close to the G-M tube window as possible, and the other with the meters out of the area with the window open for background. Repeat this for better results. If there is no change, than it wouldn't be radium, since some of the Ra-226 daughters emit very high energy gamma rays, e.g. bismuth-214, which easily penetrate glass. I have A LOT of various Ra-226 sources, and all of my Geiger-Müller counters can easily detect them, some through concrete and lead bricks.
These are ammeters. You can see in the lower right, right of the pointer pivot and slightly lower, FS= 1ma DC. That means that full scale (FS) is 1 milliampere. Often these ammeters are labeled "volts," but are ammeters designed to be used with an appropriate circuit. (usually a series resistor) Some have a series resistor " in the can" so to speak, and are thus "voltmeters."
In a sense, all such moving-coil meters are ammeters because the principle on which they work is current flowing through windings immersed in a magnetic field. But as @excavatoree explains, we tend to name meters for whatever the dial is labeled.
Americium 241, only .9 uCi, VEEERY weak gamma rays and lots of alpha particles that are stopped by the little shield, as well as most of the gamma, very weakly radioactive, measuring outside the casing
I had a physics professor bring over a fancy geiger-counter to check over my Collins R-392 military radio. It had a small barely glowing tuning meter. The counter showed 13 millirems/hr at 4 inches away. Pretty high, even it was probably about 8 half-lifes run down.
I suspect that the heavy cases on the meters had a lot more to do with protecting the instrument than with protecting the operator. That kind of thinking didn't really become common until decades after those meters were built... Fascinating stuff. Thanks Fran!
you are correct.
I really like old dials and meters.
The problem is that the steam-punkers are driving the prices up!
@@dahdahditditditditditditda7536
What's a steam-punker?
@@rudolphguarnacci197 Well, that's my own made-up term. Some people make sculptures out of old electronics and old mechanical gear - which is what I mean.
@@dahdahditditditditditditda7536
I like it, Dah-Dah-Dit. It's original.
I used to live near the UK National Physical Laboratory. They luminised instruments during WWII, and also were the national centre for radium sources for medical treatment. About 20 years ago that area of the site was demolished and given over to housing. They had to dig out about 6 feet of earth, then put down an impermeable membrane because of the contamination.
Awesome vid Fran, love these retro videos.
According to a Department of Commerce Information Circular from 1930, the paint might contain "from 0.7 to 3 and even 4 milligrams of radium element to 100 grams of zinc sulfide.
The AN/PDR-27. I repaired so many of them while working as a technician for the US Government. I remember the Purple Rod used for testing them. Calibrating them behind lead panels was always scary business.
Any experience repairing IM-179U Radiac or IM-174a/pd?
Wow! A real radium dial. Those are so wonderful. Dad's old radio had one... The one that sat less than a foot from his head in the headboard cabinet... Wow.
Even if you have a gamma/ x-ray counter that is not directly sensitive to alpha/beta you'll pick up a little x-ray 'bremsstrahlung' from the alpha/beta particles impinging on the window of the counter.
I had one of those in high school! As I recall, it was 0 to 50 VDC ..it glowed dimly all night. It was connected to my homemade 12 volt selenium solar cell panel.
Old orange " carnival glass" was slightly radioactive. We did radiographs with a 1930s orange plate and Tri-X pan sheet film in physics class.
This was back in the mid '70s...
I like those old school analog meters..I have a few old ones, but most " evaporated" over the years...
Another cool video of old school stuff .
In the suburban Philadelphia area in a town called Lansdowne a professor processed Radium in his basement back years ago. The site became a major hazardous waste superfund cleanup site. I grew up about 1/4 mile away. The professor and many of his family have died of cancer.
I love these films where you fix things up..
What's awesome is to realize, assuming natural Radium, those clicks represent a direct connection to the energy from the death of a star.
We are all Star Stuff!
@@FranLab "Billions and billions..." so saith Carl Sagan.
The evolution of a star. The only stage of a star that doesn't emit any significant light or energy is a black dwarf, and the universe isn't old enough for black dwarfs to exist for another several dozen billion years.
we are ...✨Star Dust✨!!
We're 'dust in the wind' but the atoms of our dust was blown on the winds of novas before it came to be reborn as a planet that gave birth to us. The universe is awesome.
Hi Fran, 40yrs ago I watched someone restore those meters !! It's a real pain in the A-- !!! Because you need LOT'S of lead shielding and a positive pressure air mask !! The guy worked at Oak Ridge !
I never knew that the phosphorus is what's actually glowing! Very fascinating!
She said "phosphors" not "phosphorus".
These old instruments are works of art. One thinks to be able to recognize the quality by the care of the production. At that time, the appearance of an instrument was still very important.
And it’s not important now?
It should be. But how can one achieve the charm of a pointer instrument with a digital display?
Yes. Analog displays don‘t need to be read. They only need to be looked at. When I was young I had a beetle, 80 km/h (50mph) was reached when the pointer was up. To read a watch is way easier with an analog one, e.g. showing that it‘s closed to 12:00. 11:49 on a digital display has to be read carefully....
Thanks! I was aware of this aspect of the two dials on my vintage US military short wave radio Collins R-390A/URR but had not found the explanation of it yet. I now get why these dials are taken out if the crystal shielding is damaged.
Wow, I haven't seen an AN/PDR-27 in years. Not since I was in the Navy.
The Army used them too
@@mshotz1 It was also used by the Air Force. BTW, the AN designation stands for Army/Navy.
That's pretty cool. It seems like those would actually be fairly safe to use in a project. I'd probably use one in a home made Geiger counter just because it would amuse me.
I still have the Baby Ben alarm clock I bought in 1972. The phosphor has been nuked off over the years so there's is very little glow when hit with bright light then put in darkness. However, it still scintillates when your eyes get dark adapted and you can see the little sparkles when you look through a magnifier. We used to do this in physics class in the 1960's with an alpha source in a tube with attached magnifier. Later, the alpha source was taken away by school officials, but we still was playing with the spilled mercury found in the windowsill that oozed up from the woodwork that a student spilled several years before. Today, if a cracked old mercury thermometer is found in one of the old school cabinets, it is red alert!
Thanks for the video on these. Love those old units.
I used to live near the National Physical Laboratory in Twickenham in the UK. They used to luminise instruments there for aircraft during WWII and after. They also were the supplier of radium for medical purposes. Later they wanted to build houses on that part of the site, they had to dig out to 2 metres deep and seal the land.
That thought about how vintage tech has a lot of radium in it triggered my memory about the story of The Radioactive Boy Scout who managed to collect so much of in in his small shed that it was eventually declared a hazardous radioactive site and the cops had to call in the EPA to clean it up. His radioactive source wasn’t from vintage stuff though.. it was harvested from pilfered smoke alarms lol. What an idiot.
It’s a great book. He ended up getting a job in the Navy.
David Hahn built a fast breeder reactor, with americium-241 from 200 smoke detectors, Uranium from Czechoslovakia, Radium from old clocks and the mantles 1950's lanterns, and Lithium from batteries. He died aged 39 due to 'alcohol poisoning'. Taylor Wilson also built a reactor but his was a Fusion reactor, he is still inventing new things.
@DARK APPERITION a pile reactor, which is exactly what it sounds like, also his sources were very widespread, i read he had an extensive collection of radium paint and old clocks in his collection as well as other stuff, he was said to have collected anything radioactive.
He had lazy parents that couldn't be bothered with what their son was doing. When hos mother found out she was more worried about herself then her son.
There is an article I found that does mention specifics and goes into detail about the amount of radium in paint and goes into detail about the composition of them
Love the Green Glow of Radium
You can get the same with tritium much easier.
@@evensgrey And you can buy Tritium at amazon easily... Not sure about Radium
Great video, Fran!
My Grandfather, I'm 62 btw, had a watch that glowed in the dark, but only the 12,3,6 and 9 had little rocks of yellow embedded in the points and the hands glowed brightly as they went by the rocks, and slowly dimmed as they were away from the rocks. He said he got it in Egypt, and that the rocks were Uranium, and the hands had some Zinc paste on them. The hands glowed a blue color and the 4 points a greenish light not as bright as the hands. Near the 3, there was a moon that changed size for the waxing and waning of the moon, and it glowed as well But I can't remember the color maybe a sort of yellow, there was a picture of the man in the moon or something like that on it. He did this trick where he held his watch up to another watch that had 'normal' radium paint on it, and the other watch would glow really brightly.
Very interesting episode thanks! Reminds me of the scene in Dr No when Bond tests his geiger counter by putting it against his watch dial.
There's a museum near me in Ottawa, IL that is dedicated to the radium girls. Sad, but interesting history.
I really miss the radioactive painted dials. Especially on my watch.
Crikey, I used to fix clocks when I was young, lots of them had dials & hands which “glowed”, but I’ll never know if any were *proper* radium ones... oh just remembered about the box of old panel meters stashed under my bench...might be time to get a geiger counter :-)
If you do not have a radiation detector, it is probably safest to assume that any "glow in the dark"-looking paint on older clocks or instruments will contain radium, the use did decline in the latter half of the 1900s, when alternatives became more common, but I wouldn't trust anything before 1970 at the earliest without testing it first(this might depend on where in the world you live, of course)
The primary risk is probably not from exposure to the radiation of the dial and hands, but rather ingesting or breathing in the dust that might have collected inside or come detached during the work, so taking precaution against dust is probably best if there is any doubt.
Very Cool Fran! Thanks for sharing.
Many years ago, my parents had some green glass bowls which turned out to be a bit radioactive. It seems they used to use uranium compounds to get the nice colour!
"Gosh ms.mallison these oranges stay fresh forever when they're in this green bowl for some reason, I wonder why?!?!"
I was told by My Jeweler that to some of the early watches and meters used polonium instead of radium because it was less expensive also I have a Korean war-era military Jeep (m38a1) and the speedo is radium lettered and still glows brightly to this day.
Ah you mean Promethium-147. It was safer than radium. It had a half-life of 2.6 years. Compared to Radium’s 1,600 year half-life.
Excellent video! Was literally thinking 'that's lead crystal' just as you said it... It occurs to me the dimness may also be down to radium decay, as well as phosphor degradation., but I dunno what its half-life is.
1600 years.
I was also thinking it was probably leaded glass!
@@alankingvideo Wow. Guess not then. Does that mean the old-style pure radium lume with no phosphor is still as bright as when it was applied? I thought all old radium dials were dim nowadays.
Trump's Tiny Hands From when I looked into this about 20 years ago, it became apparent that the high radium content products were pretty much all identified years ago and disposed of in landfill. It was widely recognised in the 1960 that these items were very dangerous if fragments were inhaled. So we are left with WW1 compasses with radium/ phosphor paint added to the inside of the glass. Watch dials and meters. No toys or pots of paint. Unless someone knows differently. However I dread to think what’s under the old wallpaper in some houses, painting stars and moons on children’s walls was pretty popular.
Pretty nifty dials!
I've always loved leaded glass :)
DON'T lick the paint brush Fran!
Damn everyone is always ruining the fun
If i replace the phosphors on my R390 meters will they work again ?
AH, The Warmth and Glow of Radiation..
Very interesting. Thank you.
Very cool! I don't suppose you would consider parting with a few old meters? i need 3 for my transmitter 100ma full deflection or less not picky.
I could make 50 ma work too. The ones i have are old and crappy, they stick sometimes and are not the same shape and size. Yeah i could get new ones but they're new, just a thought. I forgot about the haul from the uni years back....makes me think i've been watching you for quite a while now time does in fact fly by.
Have you done a video about your Geiger counter?
Weston Meters were made in the UK and USA by Sangamo Weston, and the differences between the two are very minor but they have different model numbers. Some later models were made by other manufacturers under licence. The US company was founded in 1888 Springfield Illinois as a manufacturer of electrical measuring instruments with a factory in Newark NJ, with the UK company following on in Enfield Middlesex a year later.
In 1954 the US company was bought out by Daystrom, then in 1962 Schlumberger took over Daystrom. In 1974 the Newark plant was shut down. In 1987 there were investigations going on over contamination of the surrounding land. Sangamo manufactured PCB-containing electrical capacitors there during 1955-74. Sangamo notified the US Environmental Protection Agency of its disposal of approximately 38,700 cubic yards of PCB waste on its plant site and an undetermined amount in seven satellite dumps, all in the Twelve-Mile Creek Basin. Solid, sludge, and liquid wastes were stored or disposed of in piles, landfills, and impoundments. How nice! Since then Sangamo-Weston has removed over 17,000 cubic yards of waste from past disposal areas on and off the plant property. How sad it should all end this way - I'm sure Edward would be turning in his grave if he knew.
Are those painted with Undark?
What did they measure?
Now could you paint over the numbers with fresh phosphorous and get it to glow again
And does tritium vials have less emitted radiation
A great little video. Imagine all those people who were woken by alarm clocks which were dosing them in radiation all night. I still have my 1970s TIMEX childs watch I wore, with its glow in the dark hands and hour markers. I'm guessing it may still click a little, although it had a thickish glass front.
If it's radium it's just as radioactive as the day it was made, but usually the glass stops most of the radiation, no worries
another frantastic video. thanks for this video.
If you take a loupe, say 30X, and look at the radium phosphor in the dark, you’ll see little sparkles around each disintegration.
tritium dials are kinda cool too
And to think that thousands had these clock radio right next to them while they slept! Surprised they didn't glow after they woke up!
Cool video, Fran! That said, the part I immediately went back and played again was the closing credits. What a fantastic groove! Is that on a record somewhere?
What is the model of that detector?
So Fran, at 1 foot what is the hazard? Is it dangerous at one foot?
But is it really Ra-226? There is little information about that, but Ra-228, Th-228 and Sr-90 were being used, too.
Also don't forget that the radium itself decays; the isotope with the longest halftime is 1600 years, but the runner-up is only 5.75 years. After a few decades quite a bit of radium may be gone.
The longer the half life, the less radiation it puts out, and the less it will glow. With a half-life of 1600 years in it's most stable form, it is no longer nearly as dangerous, but will also no longer glow enough to be useful. It will take a long time for most of the radium to decay to that state, though.
In the older meters & such, we don't know that they isolated for shorter half-life isotopes. I know I've seen WW2 era meters (almost 80yrs) with dead phosphors that are still hot as heck. Too bad Geiger counters aren't cheaper to have on the average tinkerer's workbench.
True, but some of the radium daughters are even "hotter" than the radium itself.
@@rich1051414 Actually, the main issue with radium paint is not radium decay-with a 1600 year half-life, the decay is not important in the short-term.
HOWEVER, as Fran noted, the phosphors in the paint DO deteriorate.
The radiation itself does that, and moisture speeds the process up.
Of course, time is a major factor as well.
Some alarm clocks from 1968(which was pretty much the last year radium was used in them) will still have a faint glow even after being in the dark for a long period of time, even though they are not too well sealed.
The older ones generally have ZERO glow(except under UV light).
Fran's meters are way older, but due to they being totally sealed, the faint glow still remains.
@@ordinaryaverageguy76 It does not matter much:radium 226(which was the primary isotope used) has a 1600 year half-life. So the meters can still be quite hot with totally dead phosphors.
Nice find
I've seen a lot of regular, panel meters at the surplus places I used to go to, but I've never seen a radium dial version. (or if I did, it was when I was young and didn't realize it.)
Sadly, they are all out of business now. I should have taken every panel meter the last guy had, but I didn't. (but I've still got quite a few, and my dad has some as well)
I love radium dials. I know "radioactivity is bad" and stuff… I'd probably wouldn't leave it in my pocket but a watch is fine and you could actually see it in the dark as opposed to whatever they use in watches now. Cause that new stuff doesn't glow what so ever.
are old darkroom timers hot too?
Thank you!
I have not been able to fully shield the Gamma rays from Radium/Radon daughter's without having to use very thick lead
Very interesting video!
Great Video
Very interesting, love it. Do these instruments really have the exactly same SN 175318?
Pretty cool. I'm also curious about that geiger counter, it's obviously not the typical old Civil Defense relic. Looks like a Fallout prop!
Not CD-it's an military model-AN/PDR-27S
The one Fran has is a demilitarized version renamed as the HDER-1
Same meter, with the test source removed
Yes, Fran. More like this. Ancient electronics porn. The music at the end is genius. I could see it getting old at some point, but right now, it's great.
Don't forget the story of the radium girls
Right. Those that died while wetting the paint brush while painting watch dual faces in watch manufacture.
_Licking_ their paint brushes.
en.m.wikipedia.org/wiki/Radium_Girls
Recently read that book. So sad ...
@@dahdahditditditditditditda7536 Yeah its a pretty Sad and horrific way to go.
Be careful not to open or break the glass/celluloid cover on old clocks and watches. Inhaling or ingesting the dust from that paint is lethal. I got a ww2 pocket watch recently, and didn't even think about radium until I'd had the back off and looked inside... 😓😵😱
I remember back in the 1950s you could buy tins of Humbrol luminous paint and as far as I know it was radioactive. The withdrew it in the 1960s because kids used suck the brushes after painting here glow in the dark model skeleton kits.
Beautiful meters Fran! God I love vintage meters. Doesn't the inverse square law only apply to an isotropic radiator? Surely a highly collimated beam doesn't behave this way. Unless I'm wrong of course. Haha. Thank you for the fun and VERY interesting vids Fran ~{:-]
Is the shield on the end the wrong way round? it shields the gamma tube while open..
right? I noticed that too after seeing the second cable going to the little tube but thought maybe like it's some sort of two option fancy detector wand....geiger-mueller?
[edit] 5:50 oh neat :D
At th-cam.com/video/DWM5MVmHZUM/w-d-xo.html you can see that it is not or not completely covering the gamma detector. The lid for the particle detector tube is to thin to shield gamma radiation.
@@berndeckenfels would it not read more accurately without the obstruction?
tomnwoo hm possible, don’t know but those counters are just a rough guess anyway
@@tomnwoo when measuring Gamma, the cover is closed.
You only open it to read Alpha and Beta.
With the cover closed, the large tube is used for Gamma on the lower ranges, and the smaller tube is used on the higher ranges.
Is the fluorescence green uranium glass radioactive?
Yes, it emits a small amount of beta radiation.
It's a mild source. Don't eat off it!
@@FranLab *looks up with spaghetti face*
You have to be careful when you buy surplus stuff. Vacuum tubes sometimes contain Thorium.
I have an old Western Meter, it is a model 301, it weighs about 240 Gram's. But mine has a silver like face on it.
radium should still be used safely of course it make some of the best glow in the dark stuff
Tritium glow tubes are still available and are much safer
Very cool
Awesome sauce😆
Radium emits a weak 186 keV gamma but it's daughter's have much higher and more penetrating Gamma Ray's. Namely Lead ²¹⁴ and Bismuth ²¹⁴ this was from HPS.org
As you know, both 214Bi and 214Pb emit measurable gamma rays, and both can be useful in the indirect determination of 226Ra, a precursor in the decay chain that produces the lead and bismuth progeny. The 214Pb emits lower-energy photons than does the 214Bi, the three most abundant gamma rays from the lead being at 242 keV (7.43 percent), 295 keV (19.3 percent), and 352 keV (37.6 percent). The dominant gamma rays from 214Bi are more in number and higher in energy than the lead gamma rays; the range of useful energies is from about 600 keV to about 2.5 MeV. The bismuth gamma ray of highest yield is at 609 keV (46.1 percent); there is a gamma ray at 1.12 MeV (15.1 percent) and one at 1.765 MeV (15.4 percent). The others have individual yields no higher than about 5 percent.
I think a tear down would be informative to see what indestructo work had been done on these.
They wouldn't present a serious risk by being opened given the comparatively limited radioactivity of radium paint, but even so, I wouldn't open them just from the point of preservation.
I love that stuff!
A lot of meters are painted with things other than Radium, like mesothorium, which is insanely radioactive, with a half-life of about 6 years. So it's likely those dials, if they are 60 years old, will be down to about 2^-10 of their initial radioactivity, or just one part per thousand of the original activity!
Really interesting video, thanks :-)
Are the meters still working? 100 Amp full scale?
Saw the comments - only 1 ma, still solid hardware.
Look carefully at the meter face lettering. They don't say amps but they do say 1mA full scale.
With the proper shunt, they probably could do 100 amps full scale.
@M. K. No question about it.
@@m.k.8158 You, Sir have made my day! Great answer. Only now I want one of these retro meters even more.
By having them sealed, wouldn't they be protecting not just the operators but also the instruments themselves?
There is one thing you didn't mention. What were these gauges used for? There is no indication of measurement on them. Just a graduate from 0 to 100. Amps? Watts? Voltage? Temperature? The angle of the dangle? What?
Tritium dial?
i would have expected those to be brighter
Love your videos wish I could afford to get on patreon with you
Do these meters work?
Almost certainly. I have sealed meters older than those & they work fine.
Um, when did radium exit the retail sphere? I'm sure my first wristwatch in the Sixties glowed for hours after eliminating any light source.
Also, no need to capitalise the elements, folks, unless you're capitalising the first letter of every word in a sentence for... I don't know what for.
Radium doesn't need any exposure to light. It glows all the time from its own radioactivity.
Thanks for the reply, I understood about radiation, I was enquiring about withdrawal from sale and when did that happen?
@@philt4346 radium started being phased out in the 1960s, IIRC.
Pocket watches were first to remove it, with wrist watches a bit later.
Table clocks(alarm clocks mostly) were available until the late 60's(1968)?.
Westclox made vast quantities of Big Ben & Baby Ben clocks with Radium dials/hands(many other companies did so as well).
@@m.k.8158 Thanks M.K. and you've nudged my recall somewhat with the staggered withdrawal schedule ringing a bell.
I DO NOT think these contain Ra-226. These were probably re-lumed or never had radium. Not all old instruments contain radium, military or not. For military instruments, if the paint isn't tan or doesn't look "burnt", it's probably not radium. I would do a timed count, for about 10 minutes: One with the meters as close to the G-M tube window as possible, and the other with the meters out of the area with the window open for background. Repeat this for better results. If there is no change, than it wouldn't be radium, since some of the Ra-226 daughters emit very high energy gamma rays, e.g. bismuth-214, which easily penetrate glass. I have A LOT of various Ra-226 sources, and all of my Geiger-Müller counters can easily detect them, some through concrete and lead bricks.
Are they ammeters or voltmeters?
These are ammeters. You can see in the lower right, right of the pointer pivot and slightly lower, FS= 1ma DC. That means that full scale (FS) is 1 milliampere. Often these ammeters are labeled "volts," but are ammeters designed to be used with an appropriate circuit. (usually a series resistor)
Some have a series resistor " in the can" so to speak, and are thus "voltmeters."
In a sense, all such moving-coil meters are ammeters because the principle on which they work is current flowing through windings immersed in a magnetic field. But as @excavatoree explains, we tend to name meters for whatever the dial is labeled.
@@excavatoree ammeters need to use a parallel resistance called a shunt to measure higher current.
How about smoke alarms?
I think those use americium and in tiiiiiiny tiiiiiny amounts.
Americium 241, only .9 uCi, VEEERY weak gamma rays and lots of alpha particles that are stopped by the little shield, as well as most of the gamma, very weakly radioactive, measuring outside the casing
Another reason not to open them is possible accumulation of radon gas inside, assuming they are really well sealed.
Compared to the amount of Radon in the basement of the house I grew up in.... yeesh!
thank you good imfo.
That detector wand looks like a lightsber ...if Star Wars had been made in the 1940's
I had a physics professor bring over a fancy geiger-counter to check over my Collins R-392 military radio. It had a small barely glowing tuning meter. The counter showed 13 millirems/hr at 4 inches away. Pretty high, even it was probably about 8 half-lifes run down.
benim radyum vereceğim ... rica ederim
Nice vintage display...
"dark mode" isn't just a new feature for cellphones.
Might have just been well made for durability not to protect the users .