30 cm/12 inch Diameter Gazing Globe Mirror Ball

MUY BUEN ACABADO, ACERO INOXIDABLE AL ALTO BRILLO, MUY DECORATIVA; TOTALMENTE RECOMENDABLE

Muy bien algunas un poco maltratada pero bien 👍 llego muy rápida creo que eso también importa mucho . Volveré a pedir . Gracias 🙂

La esfera llegó abollada. Por tiempo (necesitaba usarla al otro día de la entrega) intenté repararla. No encontré forma de quitar la abolladura, por lo que llegué a la conclusión de que un gorila le metió tremendo coscorrón.

Finally decided to cross a DIY project off my bucket list; an electrometer for Earth-science research. I have long wanted a metal sphere for this but didn't know how to get one affordably, so I let this project rot in my head for years. Finally just happened to run a search on Amazon and was surprised to find that these silly "gazing balls" for gardens and such are actually real metal. So, I ordered an 8 inch "silver" one and hope it would be suitable and not too heavy for the project. It arrived today and yep I'm actually pretty impressed. It's VERY lightweight. So lightweight that I could see it actually being an escapee in a windstorm, lol, but fortunately it'll be well fastened down for my project so I really don't care... in fact being so lightweight is a definite plus so it doesn't crush the box it'll be affixed to. The construction appears to me to be chrome plated steel, because it is very silvery, more so than I would have expected from even highly polished stainless, but what do I know really. The surface quality is a little bit uneven, which doesn't exactly surprise me given that it was only $20. For my purposes it's a big so what, and from any distance it looks like a very neat, accurate reflective sphere. The reflection itself is very good, very clean. There is a noticeable equatorial bump from where they clearly welded two half spheres together, but again that's not a terrible thing. If I were using this for decor, I'd line that seam up so that it was minimally visible and that would be that. Again from any distance, it would reasonably hard to notice. On to the important stuff - electrical properties!! I found it a little difficult to get good contact with multimeter probes but once I did I managed to read a low of just 2.5 ohms from side to side. That may be residual difficulty in getting good contact or it may be the meter itself, or perhaps stainless or the possible overcoating may simply exhibit some small resistance, but regardless it's fine for my purposes. I saw someone in the reviews asking about use for a Van De Graaf generator - I'd say emphatic yes, it'll work very well for that. One small concern I have - this feels as I mentioned, VERY light. Mine is 8" diameter and just 320 grams, or 0.7 pounds. That means it is very thin metal, and THAT means it's potentially delicate. Don't play football with the thing and I think you'll be fine. Make sure you've affixed it to some kind of supportive surface so it doesn't try to go wandering in a storm, and you'll be good to go. One last thing... Since I am using this as an antenna, I need a solid connection to the metal. I dabbed a tiny spot of regular hardware store solding flux paste onto the desired spot on the sphere and hit it with good electronic solder and my Weller pencil iron turned up to max heat, and in seconds I had a very nice solder weld to the spot. Stainless is a terrible heat conductor, so it doesn't take much applied spot heat to get it crazy hot in that spot. Easy peasy and I didn't have to drill to get my connection. That's a big yay. Now it's on to designing the electrometer transimpedance amp and I'm good to go for testing. Maybe I'll come back in the future and post some pics of it once (if) it all goes well. Final result will go outside on my back porch rooftop, so I need to go to lengths to weatherproof and all that, but if it works like I want, it'll be pretty amazing. It'll be added to all my other 24/7 Earth science graphs on my website, alongside such craziness as my SBM-19 Geiger counter and my Earth magnetic field listener. Crossing fingers for a win for 2024, hoo-ah! NR417

I was expecting the surface of the globe to be more optically perfect than it is. Sadly the surface is covered with really fine scratches which show up under bright reflections. Probably the result of less than quality polishing of the surface. (see photo) There are place around the globe where the polishing defects show as permanent smudges that don't clean out and the seam where the two halves of the globe join is evident around the globe because of poor finishing of the weld. This globe was purchased with the intent of using it as a quality image reflector for closeup & medium closeup photography. It does not meet those expectations.