What tool in a molecular bio lab screws up my bluetooth headphones?

April 20, 2022 10:11 AM

At least twice a day I walk past a wet chemistry lab that appears to be working on tiny biological stuff. (I'm sure I'm describing that badly. But, they have test tubes full of liquid and posters about stuff inside cells on the wall.) Doing so reliably makes my bluetooth headphones crap out and often disconnect. It seems to happen at all times of day and night. Any clues what specific thing might be causing it?

I'm guessing it's something making loud radio noise at around 2.4 GHz. An NMR machine seems obvious, but all the commercial ones in a cursory google search are at are lower frequency and shielded. (Maybe it's a 3rd harmonic?) Also, they're surely not using an NMR machine at both 7am and 11pm every day, right? Any better ideas?

I have access to antennas and spectrum analyzers, but none that have batteries. I've hesitated to try to string together enough power cords to investigate further. (To be clear, I'm not going to complain or try to make them stop whatever they're doing; I'm just curious.)

posted by eotvos to Science & Nature (12 answers total)

Concur on 2.4 Ghz signal, but other than using an EM meter and start seeking there's not much we can do about it.
posted by kschang at 10:20 AM on April 20, 2022

Do you ever see the folks who work in the lab? You could try asking them - it probably affects their headphones as well!
posted by mskyle at 10:22 AM on April 20, 2022 [5 favorites]

(Also, wild guess: they use a computer or tablet or something in there that you connected to once and your bluetooth headphones are always trying to reconnect with it.)
posted by mskyle at 10:32 AM on April 20, 2022 [1 favorite]

"Crap out and disconnect" isn't how bluetooth depairs or re-pairs, and NMRs don't run at all times day or night.

When I think "lab equipment that's running all the time that might generate noisy EM", my money is on refrigerators or fans with old, badly shielded motors in them. If you're talking about a university biolab, sometimes that gear dates back to the cold war, and in EM terms is noisy as hell.
posted by mhoye at 10:37 AM on April 20, 2022 [7 favorites]

Seconding that it's probably something big and old with a motor - likely a refrigerator, fan, or incubator/oven. Something that keeps samples warm or cold at all times will be running at all times, even at 11pm and on holidays when nobody's working in the lab.
posted by All Might Be Well at 10:43 AM on April 20, 2022

"big and old with a motor" describes centrifuges, which a bio lab probably has several of.
posted by quaking fajita at 11:02 AM on April 20, 2022 [1 favorite]

Does it have an automatic door? The automatic doors at CVS and Target do this to my BT earbuds, though I'm not sure why, since that's probably motion detection (which shouldn't be a problem). Now that I think about it, it may be the sensors CVS and Target use at entry points to check for anti-theft tags. If there's any kind of powered NFC tag reading going on at the lab door -- say for a security badge -- that's a possible culprit.
posted by The Bellman at 11:19 AM on April 20, 2022

I don’t know how widespread microwave warming of cell culture media is, but it exists, and the standard microwave oven frequency is 2.45 GHz.
posted by jamjam at 11:40 AM on April 20, 2022 [1 favorite]

Just to say, I used to spend a lot of time in labs like these, and knew lots of other people who did as well, and there were plenty of bluetooth devices in those labs that were working just fine. In other words, I really don't think this issue is being caused by a common piece of equipment working as intended; this is either something relatively rare, or something malfunctioning.
posted by kickingtheground at 12:53 PM on April 20, 2022

NMRs don't run at all times day or night.

... most modern NMRs (not MRIs, which have living samples) have autosamplers and abdolutely can and do handle overnight queues and thus do remain busy at all hours. A group doing fancier multidimensional NMR experiments on complicated substrates might frequently run 8-24 h experiments, as well. Certainly some of my own work has required it. (Though the kind of instrument needed to run these experiments is a major investment of the sort more commonly made by departments or core facilities, not individual labs.). Also, many labs absolutely have people working at 11pm or 7am, either because they allow flexible schedules for night owls and extreme morning people (like mine) or because they're horrible places that demand crazy hours.

Anyway, as someone whose various places of employment over the past 2 decades could be described as "wet chemistry lab[s] that appear to be working on tiny biological stuff," Bluetooth earbuds are common and I haven't heard people complaining about systematic issues with them and centrifuges, fridges, incubators, etc. (even old sketchy ones), or any other relatively common equipment. I agree with kickingtheground: this is probably something pretty rare or something broken.
posted by ASF Tod und Schwerkraft at 2:45 PM on April 20, 2022 [3 favorites]

Also, they're surely not using an NMR machine at both 7am and 11pm every day, right?

are there grad students with access to it? if so, no, not right
posted by solotoro at 7:40 PM on April 20, 2022 [2 favorites]

Response by poster: Thanks all. There are many plausible ideas here. I am impressed by the range of knowledgeable comments. (I work in a different place on different things, so previously connected devices would be really unlikely. Everything else seems plausible.)

I think it's time for more investigation. My plan is to see how many extension cords I have and where the nearest outlet is for a spectrum analyzer run, maybe some computer/phone bluetooth sniffer software, and then possibly contact some lab members in a casual and non-annoying way.
posted by eotvos at 2:49 PM on April 21, 2022