Vintage
On this forum I had expressed my concerns about the radioactivity emanating from my G-P ref: 7317 Gyromatic. I store most of my small watch collection on cushions in individual wooden boxes with hinged transparent lids that all fit neatly together, twelve at a time in desk draws. All my manufacturer
On this forum I had expressed my concerns about the radioactivity emanating from my G-P ref: 7317 Gyromatic. I store most of my small watch collection on cushions in individual wooden boxes with hinged transparent lids that all fit neatly together, twelve at a time in desk draws. All my manufacturers’ watch boxes are stored elsewhere in archive. The innocuous looking luminous hands and indexes of my Gyromatic indicate “off the clock” readings on my little Geiger counter, which has a maximum register of 9.99µSV/hour.
From calculations based on a few measurements at varying distances (using inverse square law) from my Gyromatic, the true “spot” radiation is approximately between 13.0µSV/hour and 15.0µSV/hour, which is quite high and probably harmful to my wrist and body over time. So last weekend as an experiment I lined one watch box internally with six panels cut from some scrap lead sheet 1.8 mm thick to completely screen my environment from most of the stored Gyromatic’s radiation. The transparent lid is now blocked with lead so the dial is hidden from view.
Below are two photographs of the results. The first is the open lead-lined box containing the Gyromatic on its cushion close to the Geiger counter, which reads 9.99µSV/hour maximum as expected. The second photo shows the box's lid closed and the closely positioned Geiger now reading 0.90µSV/hour. My home’s background radiation is between 0.12µSV/hour and 0.14µSV/hour so with the box closed, only approximately 0.78µSV/hour radiation is escaping to do me “harm” at my desk. I think I can live with that.
However from 1960’s back to 1920’s many watch dials were painted with radium-powered luminosity. What accumulated harm did they inflict on those watch wearers? After all, wearers in likely ignorance were happy to wear their luminous watches. Of course a single watch on a wrist is a point source of radiation. Retailers and manufacturers with a large number of radium powered luminous watches held in store or on display must have been detrimentally affected by the multiple sources of radiation where they worked.
Are there any records of the harm caused to individual wearers, which perhaps precipitated the change in the law in 1960’s?
How harmful is my Gyromatic to wear and should I have the Gyromatic’s dial renovated with the removal of the luminous paint, which will down-value and lose the dial's wonderful current patina?
Best
Clive
The Girard-Perregaux Gyromatic reference 7317 is notable as the original Gyromatic 39 Jewels, a model prominently featured in period advertisements for its innovative jewel roller bearings. Introduced in 1957, this reference was a significant commercial success for the brand, with a production run that spanned several years and inspired later heritage models. It represents a key period in Girard-Perregaux's development of self-winding movements.
The 7317 was produced in a substantial quantity of 34,055 pieces between 1957 and 1962, though it remained in catalogs until 1968. Production figures include 24,000 pieces in steel, 1,475 in yellow gold, 850 in rose gold, 5,530 in yellow gold plated, 1,400 with yellow gold cap, and 800 with rose gold cap. The watch features a self-winding movement with 39 jewels.
This reference appeals to collectors interested in historically significant self-winding watches and those seeking a piece from a high-production, yet less commonly seen, vintage series. Its various case material options provide collectors with choices, reflecting the diverse market strategies of the era. The 7317 stands as a testament to Girard-Perregaux's manufacturing capabilities and design approach in the mid-20th century.
And alpha particles were stopped by a sheet of paper, non-penetrative, and the risk was in inhalation or ingestion? How are they even escaping the watch itself?
Perhaps the geiger counter is in need of calibration?
Gamma radiation is emitted by radium 226 in the luminous paint and that is what is detected. Emitted beta radiation is not detected by the Geiger. Alpha is absorbed by the watch casing etc but there is the creation of Radon gas within the watch, which can leak out. The Geiger counter Radex 1503 shown also detects X-rays but that is not relevant here. There is nothing wrong with my Geiger counter. When flying above 30,000' the Radex 1503 also detects gamma radiation from space. You may be surpris
www.ld-didactic.de Interesting! A lead-lined box is likely sufficient, maybe store it away from where you normally sit. Also, I would strongly advise against licking the hands of the watch. Don't do it!
Here is a link to a long report that may explain answers to my questions but I do not understand the measurement units described with relation to µSv/hour: RADIUM TIMEPIECE DOSE MODELING Prepared by A. J. Boerner, CHP M. A. Buchholz
The thing is that if you are worried about that, you should sell it, certainly on redial it. The watch looses all its interest if you touch its " integrity ", here, the dial. Best, Nicolas
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