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Load image into Gallery viewer, Radiometer
Load image into Gallery viewer, Radiometer
  • Load image into Gallery viewer, Radiometer
  • Load image into Gallery viewer, Radiometer
Vendor
TEDCO

Radiometer

3.3
Regular price
HK$ 390.00
Sale price
HK$ 390.00
Regular price
HK$ 644.00
Sold out
Unit price
per 
Save 39% (HK$ 254.00)
Error You can't add more than 500 quantity.

  • Tracked Shipping on All Orders
  • 14 Days Returns

Description

  • Vanes in the Radiometer are alternately dark and light in color
  • Vanes transfer heat to each one but not at the same degree
  • Lighter vane reflects the rays and the darker vane absorbs the rays
  • For ages 8 and above

Shipping and Returns

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  • All customers are entitled to a return window of 14 days, starting from the date of delivery of the product(s).
  • Customers are advised to read our return policy for details of the return process, eligibility, refunds as well as cancellations or exchanges.
  • In case of any issues or concerns about Shipping or Returns, please contact us and we will be happy to help.

Customer Reviews

- A fascinating device of science-The explanation given for the movement of a radiometer is something about difference in temperature. I beg to differ. I've used a Tesla coil to rotate this one and monitored the Temp using a thermal camera. There was No heat flux occuring, simply ionization of the gas inside the sphere. Eventhou description says there is a vcacuum. There can't be because some gas is glowing greyish blue, which began to glow, when the coil was activcated. Having said that, this is an interesting device. Judge for yourself the source of it's motion. 5Fascinating, But Does Not LastThis fascinating little gadget has been around for years. It is the approximate size and shape of a clear, standard incandescent lightbulb, with a base to stand on. Inside, instead of a filament, there is a small structure of four square vanes held atop a sharp needle, allowing the apparatus to spin. The vanes are colored white on one side and black on the other. Through action of direct sunlight, the vanes spin; the brighter and clearer the light, the faster they spin. The physics of it are explained on an insert. No batteries required, just put it on a sunny windowsill and watch it go!This really is a terrific and fascinating demonstration of the power of the sun. No matter that now that I am older I understand the physics of it, it is still a remarkable and awesome thing. Fun for young and old, it is probably more suitable for older children who are beginning to express interest in the workings of the world around them and for grownups who still retain a measure of wonderment of natural processes like solar power.But for its durability, I would easily have given this five stars on coolness and educational merit alone. There is no denying that this is a delicate item, unable to withstand the rigors of a toddler's attention; mine was immediately put on a sunny windowsill where, after spinning smartly for two weeks, it quit. It seems another factor of physics, that of friction, led to its demise. Whether the cap that rests on top of the needle wasn't made of tough enough stuff or whether an initial dab of graphite lubrication manufactured-in would have helped, I don't know. (I'll not leave the question begging: Yes, it was perfectly sunny when it stopped) The vanes are not stuck, as the device does wobble and spin through physical action of rotating the unit, but they can no longer move solely through solar power.I thought the cost reasonable initially, for such a cool device. But it's no value for a lifespan of two weeks and far more than I would have wanted to spend on a paperweight.I am reluctant to give what really should be an excellent little scientific experiment three stars. Maybe mine was a dud - I really hope so, because like so many others I rely on ratings on Amazon to help with my purchasing decision and I would hate to think some would not be able to experience this based on ratings. Caveat emptor, then, for those who want to go for it: I think you'll love it, but it may not last. 3chatuoe'orniment'Nice piece of scientific kit to have 'anging round the lounge! 5Poor quality item but Amazon is awesome!This item arrived with a manufacturers defect in the glass (small bubble/hole) that had had already started to crack/crawl down the glass. Technically/ideally these are supposed to be in a vacuum though I'm not sure how the lack of one affects performance. Regardless, it still doesn't move at all when I shine a light on it (tried both a high-frequent purple laser and a full spectrum white bulb). Amazon refunded my purchase so I'm not upset & I'll be ordering another radiometer but not from the same manufacturer. I can't recommend this brand. 1Junk. Not a real radiometer. Not the same as is pictured!It arrived falling out of the package, and mailed in a plastic bag. It CAN'T be in a vacuum! It would have been tossed around too much to keep a vacuum. The whole thing is plastic. I had one of these as a kid and it worked in ANY light. It was a glass bulb and was cool to watch it work in ANY light. This does NOT work in any light. It is NOT heat, it is light that makes it work. This is TRASH! 1Well Constructed, Good PriceAt the time I purchased this version of the Radiometer, the Amazon price was $10.95, with free Super-Saver shipping available. I have seen the identical model retailing in science gift shops and catalogs for $12.95 to $15.95, so I was quite happy with the Amazon price.The device is sturdily constructed, for what it is. Keep in mind, this is a thin glass bulb similar to a light bulb; it will shatter when dropped. The rotating vanes inside, while intricately crafted, are delicate and not designed to withstand heavy shaking or jarring. It is not a "toy," particularly not for young children. Rather, it is an interesting scientific novelty, or a "curio," not intended for frequent handling.The bulb is securely affixed to the black plastic base. I appreciate the "retro" appearance of the base, reminiscent of antique bakelite. It is much more attractive and sturdy than the version I remember from my childhood, which had a piece of gaudy colored paper glued to the bottom of the glass bulb. The vanes are nicely painted and well-balanced. The unit will begin to spin when exposed to even muted sunlight. The one I received will spin quite rapidly under bright light without any rattling or shaking, unlike those I remember from years ago.I am quite pleased with this version of the Radiometer: The Sphere Powered By the Sun (I miss the phrase "Space-Age Sphere," which no longer appears on the packaging), and am ordering several more for demonstrations in my elementary school science classes... and for myself, because... what can I say... it's really cool! 5Like 0 RPMsThis product simply doesn't work AT ALL. I just got it (appears to have been packed with all the skill and intelligence of an injured llama).I put it in the back yard at 3:00 pm on a sunny Texas September afternoon and did it spin? Nope.I have video -- it's impressive how it doesn't work. I would think that under these conditions even the most poorly-built radiometer would spin a little bit. But this one does not spin AT ALL. Like 0 RPMs.I checked to make sure it wasn't jammed or stuck against the glass. I made it spin by gently moving it rhythmically for a few seconds. But sitting in the directed (intense) sunlight simply did NOT work at all. 1Warning, not the same as picutred!Although I purchased it directly from this listing, the radiometer I received is not the same. The base of the version that is now being sent is not flared, nor is it glossy. The bulb shape is different and the internals look very different (ie very cheap) and is off center. The top part that spins is loosely placed on top and is poorly balanced. I bought this based on all of the five star reviews but obviously did not receive the same quality of product that others did. This one bare spins in full direct sunlight and does nothing in partial sun.If you are purchasing after April of 2014 and expecting to get the product pictured....beware! 2very poorly madeThis fails even as a toy, because it is so cheaply constructed. It's as if a child made this, and not a particularly bright child, either.First, the spindle was bent and corroded. Second, the 'bearing' that the vanes spun on was so wobbly that the mechanism just shook instead of spinning. Third, the 'vanes' look as if they are scraps of paper that someone blackened on one side with a Sharpie. The ink bled through to the "silvered" side (which looks as if it is just white paper), which defeats the entire principle that the device operates on. Last, the vanes are attached by some kind of sloppy crimping that angles them, each differently. The injection-molded base is glued together with all of the craftsmanship of a toddler.The item was defective, but the supplier said that they would send me another. Nice of them, but it's still a piece of junk.My advice is to spend your money on one the German-made radiometers. You don't want your "conversation piece" to start a conversation about how shoddy it looks. 1UnsustainableI was jazzed to have this unit arrive, and I placed it in my office window, where it spun merrily whenever it got full sun for a few hours each clear morning. I'm in SoCal, and our summers are full of clear mornings. I ordered it on June 2. Sometime in the last week or two it has stopped spinning. If I tap it, or otherwise break the stiction in the bearing, it will spin half-heartedly for a few minutes, but will slow to a complete stop regardless of the amount of sunlight it receives. I don't know if the vacuum was not sealed tight or if the "bearing" degraded. At any rate, it is now a static toy. Sigh.I'm going to get another one, but not this brand. 2
Radiometer

Radiometer

3.3
Error You can't add more than 500 quantity.
Regular price
HK$ 390.00
Sale price
HK$ 390.00
Regular price
HK$ 644.00
Sold out
Unit price
per 
Save 39% (HK$ 254.00)