Helium Leak Detectors for Vacuum Vessels

June 2, 2021
 •  2:38 pm

There are many theories as to how Alvin and the Chipmunks achieved their classic falsetto sound. Back in 1958, the trio of Alvin, Simon, and Theodore forever changed the course of pop music history: first with their hit “Witch Doctor,” and then, reaching for heights previously unimaginable, with their even more enduring classic “Christmas Don’t Be Late.”

Helium Leak Detection
“We ran out of helium and can’t make it to the concert tonight Dave!”

Of course, speculation and conspiracies with regard to how these three plucky rodents went from obscurity to pop music stardom abound:

  1. The Chipmunks’ label, Liberty Records, on the verge of bankruptcy, sent music producer David Seville out on a mission to sign new acts. Stumbling upon the recently opened Gaslight Cafe in Greenwich Village, where Beatnik poets performed and some guy named Bob Dylan would later make his debut, Seville discovered The Chipmunks (then playing under the name of the Kingsmen trio). With their natural falsetto range, Seville knew right then that he had America’s next musical hitmakers on his hands.
  2. The Chipmunks don’t actually exist. Seville merely sang the songs himself, speeding up the tape to create an “unnatural” falsetto.
  3. The first theory is true up to a point: Seville did visit the Gaslight Cafe where the Chipmunks performed on a weekly basis, but that night Alvin, the group’s Brian Jones and Mick Jagger, decided that he would try to spice up their set by taking a draw from a tank of helium. When the Kingsmen took the stage, Alvin performed a helium-supplemented cover of “Moon River” that left, according to one Chipmunks’ biographer, “not a dry eye in the house.”

The most plausible origin story of the Chipmunks is the third. According to Dr. Austin Gorman, Chipmunks’ historian and author of the monograph Alvin’s Hubris: The Making of a Pop Music Icon, chipmunks do not naturally have high voices. Dismissing the Chipmunks’ non-existence hypothesis as junk history, Gorman writes that, “as we all know helium not only raises the pitch of one’s vocal range, but also creates a hilarity that resonated with listeners in Eisenhower’s America. In one way to understand the Chipmunks’ success is that the group was giving a metaphorical middle finger to the squares.” 

If we agree with Gorman’s analysis, it would certainly solve one riddle that beguiles Chipmunks’ enthusiasts and historians: the sabbatical Alvin, Simon, and Theodore took from 1962–1969. Explanations for Alvin’s Berlin years, which saw the release of three albums sung in monotone (Lodgings in 1963, followed by Alvin IV in 1966, and finally Crossing the Rubicon in 1968), often point to the Chipmunks’ lead vocalist’s persistent drug abuse and megalomania, but (ahem, Occam’s Razor), a far simpler explanation presents itself.

During the mid-1960s, helium leak tests were still in their infancy. It wasn’t until the mid-1970s that helium could be transported safely and securely interstate. The helium leakage theory makes the most sense when we take into account Theodore’s cryptic remarks in a 1992 interview with Rolling Stone regarding the Chipmunks’ “lost years.” “When the helium leaks, man” Theodore, shabbily dressed in what appeared to be a monk’s cowl, “you know you’ve lost it.”

For those of us as MPF, Chipmunks’ proponents to a man, we understand Theodore’s dilemma. The second-most abundant element on earth (you think you’re so amazing oxygen), and the second lightest element, helium also possesses one of the smallest radii of all particles: 140 pm. In short, helium atoms are just jonesing to seep out of whatever vessel they’re in. 

Herein lies the benefit of helium. Not only did it give us the Chipmunks, but it enables MPF to ensure that all our vacuum components are completely and entirely (or entirely and completely) hermetically sealed. Our vacuum system assemblies can be intricate and complicated buggers—the braze joints that connect our parts need to be sealed so tightly that no particle will even think about passing through. Having a helium leak detector and helium leak procedures in place are the perfect way to root out those pesky microleaks.

Employing a helium mass spectrometer leak detector is the most common, and also the most surefire, way to know that all the various parts of your UHV system are leakproof. At MPF, we test all of our parts multiple times (some say we’re too dedicated to quality) to make sure the equipment you receive is as leakproof as can be. 

But, we know you’re dying to ask the question: how leakproof is as leakproof as can be? Well, we measure for leaks <1×10-9 atm cc/sec—additionally, and not to brag because the engineers at MPF are nothing if not a humble lot, but we can test beyond -9 and even -10 if your vacuum chamber requires it. To put it in non-scientific terms: a leak rate of <1×10-9 atm cc/sec amounts to the release of 1 cubic centimeter of helium gas over a period of roughly 30 years. To put it in even less scientific terms: when you choose to buy a closed vacuum assembly from MPF, your stuffs won’t leak. 

For the numerous leakage tests we perform on all our fixtures of various size, shape, and volume, we use the Inficon UL1000 Helium Leak Detector. This mobile beauty is a helium sniffer detector of which dreams are made, providing ultra sensitive gas leak testing methods at highest pressures. 

Inficon Helium Leak Detector
Need leak detection, turn to Inficon.

We invite you to click on the link above to check out the specs on this bad boy, but suffice it to say, with its digital interface for uber-accurate readings, and high-detection sensitivity, MPF can ensure that your vacuum chambers will be leakfree. 

On the right, you can see the Inficon UL1000 in action at MPF. One of our large isolators is Helium Sniffergoing through the first of many vacuum leak detection methods. As a first step, we vacuum the part, before spraying it with helium. (Then, just for fun, we send in the helium-sniffing canine unit.) Finally, all our parts—large, small, and in-between—are hooked up to our Inficon to detect any helium atoms at the braze joints.

After running this test several times, testing and retesting to make sure the parts of your vacuum vessel are leak-free, we have concluded our vacuum leak detection methods.

Now, it is time for us to take a bow and marvel at the wonders of helium! Not only has it given us the greatest band in the history of the world, but it provides the key to hermetically sealing your vacuum chamber.