# What kind of scanning device can detect concealed currency? **URL:** \ **Category:** Factual Questions\ **Created:** [February 2, 2012, 7:19am UTC](https://boards.straightdope.com/t/what-kind-of-scanning-device-can-detect-concealed-currency/611520 "2012-02-02T07:19:26Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Patty\_O\_Furniture](https://avatars.discourse-cdn.com/v4/letter/p/96bed5/32.png) [@Patty\_O\_Furniture](https://boards.straightdope.com/u/Patty_O_Furniture)\ **Post date:** [February 2, 2012, 7:19am UTC](https://boards.straightdope.com/t/what-kind-of-scanning-device-can-detect-concealed-currency/611520/1 "2012-02-02T07:19:26Z")
From the Sydney Morning Herald: [Malaysian Airports To Install Money Detectors](http://www.smh.com.au/travel/travel-news/malaysian-airports-to-install-money-detectors-20120202-1qu8u.html) [/QUOTE] > [@](#): > > Malaysia is installing scanners to detect bank notes at airports and border crossings to curb illegal money outflows believed to be in the hundreds of billions of dollars over the past decade. A quick scan of the wiki article on the ringgit doesn’t reveal any advanced detection mechanisms. > [@](#): > > Security features on the banknote include a watermarked portrait of the Yang di-Pertuan Agong, a security thread, micro letterings, fluorescent elements visible only under ultraviolet light, a multi coloured latent image which changes colour when viewed at different angles, and a holographic stripe at the side of the note and a image that is visible only via a moiré effect to prevent counterfeiting using photocopiers. I know that dog can be trained to sniff out large amounts of currency, but this article is suggesting some sort of new technology. Any ideas what kind of device could tell the difference between a stack of polymer bills and a stack of anything else? ---
**Author:** ![psychonaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/psychonaut/32/4655_2.png) [@psychonaut](https://boards.straightdope.com/u/psychonaut)\ **Post date:** [February 2, 2012, 8:55am UTC](https://boards.straightdope.com/t/what-kind-of-scanning-device-can-detect-concealed-currency/611520/2 "2012-02-02T08:55:39Z")
I’d think that the standard handbag scanners used at airports nowadays would do just fine at this. The device itself doesn’t need to tell the difference between a stack of polymer bills and a stack of anything else; it need only show the operator that the bag contains a stack of something which could be currency. Determing whether or not it _is_ currency is the job of whoever opens the bag. ---
**Author:** ![Patty\_O\_Furniture](https://avatars.discourse-cdn.com/v4/letter/p/96bed5/32.png) [@Patty\_O\_Furniture](https://boards.straightdope.com/u/Patty_O_Furniture)\ **Post date:** [February 2, 2012, 2:29pm UTC](https://boards.straightdope.com/t/what-kind-of-scanning-device-can-detect-concealed-currency/611520/3 "2012-02-02T14:29:17Z")
So I guess that’s my question. If the existing set of garden variety x-ray scanners can provide enough clues to trigger a manual inspection, what device could the article be talking about? And if the existing crop of scanning devices has been seeing this cash on the conveyor belt all along, why haven’t they been doing something about it before now? ---
**Author:** ![Rhythmdvl](https://avatars.discourse-cdn.com/v4/letter/r/85f322/32.png) [@Rhythmdvl](https://boards.straightdope.com/u/Rhythmdvl)\ **Post date:** [February 2, 2012, 2:44pm UTC](https://boards.straightdope.com/t/what-kind-of-scanning-device-can-detect-concealed-currency/611520/4 "2012-02-02T14:44:24Z")
It’s a little robot that roams the security line asking if anyone can change a 500,000 RM bill. Given the control the government has over the currency’s composition, wouldn’t it be trivially easy to develop a machine that is sensitive to one of those components. The type and nature of the bill itself, the scent of the ink, etc. I know American money has a distinctive smell; I’d imagine any currency would be similar. Since they’re looking for large amounts, the unit doesn’t have to be that sensitive. What exactly it’s detecting, though, the government is probably sensitive about. ---
**Author:** ![psychonaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/psychonaut/32/4655_2.png) [@psychonaut](https://boards.straightdope.com/u/psychonaut)\ **Post date:** [February 2, 2012, 2:47pm UTC](https://boards.straightdope.com/t/what-kind-of-scanning-device-can-detect-concealed-currency/611520/5 "2012-02-02T14:47:02Z")
The article indicates only that the scanners are new, not that the technology driving them is. A perfectly plausible reading is that they’ve purchased and installed extra garden-variety scanners (and hired the appropriate staff to operate them) to make the baggage checking process faster or more thorough (for example, in case they previous did only spot checks, or used a less sophisticated scanning technology able to detect only things like bombs and weapons). It’s also possible that there _is_ new technology which incorporates image recognition AI for identifying things which are possibly stacks of banknotes. Again, the technology need not reliably distinguish between banknotes and worthless pieces of paper; it need only reliably flag things which look like they _could_ be smuggled currency so that a human can open the bag and check. ---
**Author:** ![LarryM](https://avatars.discourse-cdn.com/v4/letter/l/0ea827/32.png) [@LarryM](https://boards.straightdope.com/u/LarryM)\ **Post date:** [March 31, 2013, 6:27pm UTC](https://boards.straightdope.com/t/what-kind-of-scanning-device-can-detect-concealed-currency/611520/6 "2013-03-31T18:27:21Z")
I went thru LAX a few years ago and the customs agent seemed to know within $400 the amount of currency that I had in my luggage. Then was really pissed off to find that some of the bills were old $100 bills. He spent more than 2 hours tearing my luggage apart in an effort to fine more and put it over the limit. So I am sure they can detect any amount of cash that you have. ---
**Author:** ![DataX](https://avatars.discourse-cdn.com/v4/letter/d/e99b99/32.png) [@DataX](https://boards.straightdope.com/u/DataX)\ **Post date:** [March 31, 2013, 7:03pm UTC](https://boards.straightdope.com/t/what-kind-of-scanning-device-can-detect-concealed-currency/611520/7 "2013-03-31T19:03:18Z")
> [@psychonaut](#): > > The article indicates only that the scanners are new, not that the technology driving them is. A perfectly plausible reading is that they’ve purchased and installed extra garden-variety scanners (and hired the appropriate staff to operate them) to make the baggage checking process faster or more thorough (for example, in case they previous did only spot checks, or used a less sophisticated scanning technology able to detect only things like bombs and weapons). > > It’s also possible that there _is_ new technology which incorporates image recognition AI for identifying things which are possibly stacks of banknotes. Again, the technology need not reliably distinguish between banknotes and worthless pieces of paper; it need only reliably flag things which look like they _could_ be smuggled currency so that a human can open the bag and check. I think this is it - I can’t imagine there is some sort of external device that would be more accurate at detecting hidden currency than an add on to software that runs the X-rays. That may be cause my imagination is poor. I know - like the OP writes - dogs can detect them - and I’ve never heard of a device that can - nor do I believe one exists. I think the dogs can detect as few as 50 notes or so (perhaps less, but then you’d be running into too many false positives. ---
**Author:** ![aruvqan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aruvqan/32/2891_2.png) [@aruvqan](https://boards.straightdope.com/u/aruvqan)\ **Post date:** [March 31, 2013, 7:37pm UTC](https://boards.straightdope.com/t/what-kind-of-scanning-device-can-detect-concealed-currency/611520/8 "2013-03-31T19:37:54Z")
Sounds like the new RFID antiscan wallets and pouches are going to be pissing off the scanners. My new [pacsafe messenger bag](http://www.ebags.com/product/pacsafe/metrosafe-150-gii-anti-theft-cross-body-sling-bag/242663?productid=10212678&rlid=DETAIL) is equipped with an RFID scan protection pocket in the front zippy compartment. Actually, since they are enclosed in an anti-slice metal cable mesh, they might qualify as all antiscan.