Repeat??XRF Analysis of the Yellow Base of CD V-715 Geiger Counter:
1. Titanium
2. Chromium
3. Lead
4. Iron
5. No Cadmium Detected
Chemical Reactions of the earlier rusted piece:
- Dissolves in both weak and strong acids, producing a clear yellow solution.??
- Minor effervescence (bubbling) was observed.??
- No detectable hydrogen sulfide (H?S) odor ("rotten egg" smell), ruling out sulfide-containing compounds (e.g., cadmium sulfide).??
Additional Observations:
- Visible light transmittance analysis suggests the yellow pigment is chromium-based (e.g., lead chromate or chromium oxide).??
- The absence of H?S further supports the lack of cadmium sulfide pigment, aligning with??new XRF results.??
Comparison with CD V-750 Base Plate:
- The CD V-750 features a similar steel framework but includes a??tin coating on the inner surface, absent in the CD V-715.??
- Tin may act as a corrosion-resistant layer
Safety Implications:
- Lead exposure remains a critical concern, particularly for children and pregnant individuals, due to its neurotoxicity.??
- Vintage devices like these may pose risks if pigments delaminate, rust, or require repainting. Proper handling (e.g., gloves, avoiding abrasion) is essential.??
- Modern regulations now restrict lead and cadmium in paints, but older items like the CD V series?likely predate such safeguards.??
- While unrelated to school buses (which typically use safer modern pigments), this case underscores the importance of verifying pigment safety in all yellow-painted objects, especially antiques.??
Pics and files to follow?
Thanks?
On Saturday, March 22, 2025, 12:48 AM, taray singh via groups.io <sukhjez@...> wrote:
Correction?
The CDV715 is painted on both sides yellow.
CDV 750 ?bottom case?has got a??shiny inner??tin coat besides the outer yellow paint.
The pigment is a mixture Pb and Cd based compounds in the CDV 715
The rust has pushed up the pigment layer??making it more accessible to xrf
I can’t check on the ?intact?CDV715 cos too bulky and difficult to mount?
I believe both pigments are identical?
This is my opinion .
On Saturday, March 22, 2025, 12:18 AM, taray singh via groups.io <sukhjez@...> wrote:
Most likely iron case is tin plated ?responsible for the inner shine,The rust pushed the pigment up disintegrating the tin coat below.The Cd pigment becomes more prominent in the process?
The pigment is likely Pb and cadmium based .
Care when handling .
On Friday, March 21, 2025, 10:32 PM, taray singh via groups.io <sukhjez@...> wrote:
Lets compare with a shiny yellow CDV -750? bottom empty case.
Not rusted and? magnetic? suggesting a? painted iron alloy,
Xrf shot towards the outer yellow case
Both scans are? somewhat similar? but done under different physicochemical? states
Xrf show high lead? and Sn peak
Cd? barely visible ?Need longer count rate for confirmation.
I? believe? besides iron,the rest of the elements are from the?? yellow pigment
The rust has? changed the surface chemistry.
Let me know what is your opinion on this.
Never leave batteries behind,
Thanks
