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Can anyone help with info on this great find ??

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Adam Munich

Wed Jul 14 2010, 11:21PM

Registered Member #2893 Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242

^^ That's quite alot of radiation. An hour a foot from that meter (while on) and you have a 10% chance of death.

Good luck!

Patrick

Wed Jul 14 2010, 11:34PM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

Proud Mary wrote ...

If we are extremely conservative, and assume that the elderly vacuum capacitors in
this Jennings meter draw as little as 10uA field emission current at 100kV, then we would have about
2.5 Gy/hr at a distance of 10cm from the tube, a non trivial quantity.

wholly crap!? i reiterate my previous statement: " X-rays are only fun to play with when they dont cuase death."
i think we need here the comments from an ace radiation expert, if there are a few on the forum.

and remember distance is the best defense against anything.

also, as i said previously in this thread, a scintilation counter would settle the debate with definate measurements.

Proud Mary

Thu Jul 15 2010, 12:26AM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

Grenadier wrote ...

^^ That's quite alot of radiation. An hour a foot from that meter (while on) and you have a 10% chance of death.

I'm not sure that exaggeration is necessarily helpful here!

At a distance of 30cm, the dose rate would be of the order of 150 mSv/hr and 13mSv/hr at one metre.

To put these figures into the perspective of the UK IONISING RADIATION REGULATIONS 1999 & RADIATION DOSE LIMITS
which came into effect on January 1st 2000

IRR99 DOSE LIMITS

To limit stochastic effects the dose limits are

1 Radiation workers >18 years:
The effective dose shall be 20 mSv in any calendar year

2 Members of the public:
The effective dose shall be 1 mSv in any calendar year

3 Trainees aged under 18 years:
The effective dose shall be 6 mSv in any calendar year

To prevent deterministic effects the limits are 1 Radiation worker >18 years:
The limit on equivalent dose for the skin, hands, forearms, feet and ankles shall be 500 mSv/year

2 Radiation worker >18 years:
The limit on equivalent dose for the lens of the eye shall be 150 mSv/year

3 Trainee aged <18 years:
The limit on equivalent dose for the lens of the eye shall be 50 mSv/year

4 Trainee aged < 18 years

The limit on equivalent dose for skin, hands, forearms, feet and ankles shall be 150 mSv / year

5 Women of reproductive capacity

The limit on equivalent dose for the abdomen shall be 13 mSv in any consecutive period of three months. Once a pregnancy has been confirmed and the employer notified, the equivalent dose to the foetus should not exceed 1 mSv during the remainder of the pregnancy.

IntraWinding

Thu Jul 15 2010, 12:49AM

Registered Member #2261 Joined: Mon Aug 03 2009, 01:19AM
Location: London, UK
Posts: 581

Grenadier wrote ...

^^ That's quite alot of radiation. An hour a foot from that meter (while on) and you have a 10% chance of death.

Good luck!

Is that right?

Patrick

Thu Jul 15 2010, 01:04AM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

Proud Mary wrote ...

At a distance of 30cm, the dose rate would be of the order of 150 mSv/hr and 13mSv/hr at one metre.To limit stochastic effects the dose limits are:

1 Radiation workers >18 years:
The effective dose shall be 20 mSv in any calendar year

so you could use it for 90 mins a year, at 1 meter. And maybe not have any health effects.

Ok, sparky99, try not to die.

a stopwatch and scitillation couter would be useful.

Adam Munich

Thu Jul 15 2010, 01:14AM

Registered Member #2893 Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242

@intrawinding No, sorry. I did the calcs again and it *could* be .17 Sv/h. That could be 7% mortality rate after 6 hours.

STILL, that may be 2mSV a minute, And 4 minutes in front of that meter would be the equivalent of one CT scan!

Also, don't forget there are TWO TUBES!

Also, does anyone find it odd that we haven't heard from sparky again...?

Proud Mary

Thu Jul 15 2010, 01:23AM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

Patrick wrote ...

so you could use it for 90 mins a year, at 1 meter. And maybe not have any health effects.

Ok, sparky99, try not to die.

a stopwatch and scitillation couter would be useful.

Well, I'm sure someone will say that no harm will come from using the contraption to measure something for a minute or two, but I for one sometimes have experiments running for days on end, so without an awareness of the radiation hazard, consequences for health could follow.

Adam Munich

Thu Jul 15 2010, 01:25AM

Registered Member #2893 Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242

^^ i would still make the shields i described earlier though.

Patrick

Thu Jul 15 2010, 01:30AM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

its amazing any of our grandparents/parents survived the 1950-60's with safety standards so inadequate, if they existed at all.

radiotech

Thu Jul 15 2010, 02:19AM

Registered Member #2463 Joined: Wed Nov 11 2009, 03:49AM
Location:
Posts: 1546

Patrick wrote "its amazing any of our grandparents/parents survived the 1950-60's with safety standards so inadequate, if they existed at all."

The hazards from industrial apparatus are multiplied in 2010 by a number of factors not present in 1960.

The marketplace is global for hazardous surplus gear because of the internet and free trade treaties.

The information available in previously cloistered specialty areas is available to anyone now.

The networking of people who would be interested in unregulated hobby applications of hazardous gear is possible globally.

During the economic life of hazardous gear, it was managed by
people who were legally mandated to keep abreast of all the information the manufacturers were required to provide to keep the gear serviceable. (parts-retro kits-bulletins) After the stuff becomes obsolete, those who knew it well are likely retired.

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