multi gas analyzer full of interesting sensors - Page 1
Forum section: electronics / projects

author: oz2cpu
author_rank: Frequent Contributor
timestamp: November 20, 2024, 08:09:26 am
content: I released a little video about a medical multi gas analyzerso if you are into cool sensors, you will love this videoAndros Model 4750 thermal image 7 different sensor arayAndros Model 4710 thermal spectrum using rotating wheel 5 filtersServomex O2 transducer Paramagnetic sensorhttps://youtu.be/0UmF5F8OVwU

author: BILLPOD
author_rank: Frequent Contributor
timestamp: November 20, 2024, 01:55:06 pm
content: Good Morning Tom, Medical electronics are always full of strange components, but you do a good job of guessing their purpose. I'm presently cramped for time, so I only watched half of your video, but am looking forward to seeing the rest. Great job, as usual, and thank you for doing it.

author: oz2cpu
author_rank: Frequent Contributor
timestamp: November 20, 2024, 11:44:29 pm
content: thanks a lot, yes i am sorry it is a very long video, i did not expect to find that much cool stuff inside this unit,lucky you can FF to see the parts of most interest, it is perfectly fine to do that,you are right medical equipment is full of cool solutionsalso better manufacture quality level, safety, isolation, emc

author: vindoline
author_rank: Unknown
timestamp: November 21, 2024, 12:00:02 am
content: As a chemist, I really enjoyed this one! Thanks. One thing to know is that the optics in IR instruments are often moisture sensitive. I have no idea what the windows and lenses in your unit are made of, but the FTIR spectrometers at my company have built in desiccant cartridges that need to be replaced every year or two. We never turn the instruments off so they are always warm and moisture won’t condense inside.Cheers!

author: Analog Kid
author_rank: Super Contributor
timestamp: November 21, 2024, 05:26:36 am
content: If anyone's looking for info on Andros Inc., the maker of those very kewl sensors, you probably won't find much.I did findthis articlethat says that they were acquired by a company called Genstar in 1996.

author: CaptDon
author_rank: Super Contributor
timestamp: November 21, 2024, 06:32:40 pm
content: I used to calibrate and repair a particular medical gas analyzer known as a Poet. I think it was made by Criticare or one of the spinoffs. It used an infrared light source and various light filters. There were five gases it could detect. Sevoflourane, Isoflourane, Enflourane, Desflourane and one other. We calibrated using containers with a 1% concentration.

author: JXstaystonight
author_rank: Contributor
timestamp: November 23, 2024, 05:18:08 am
content: I just checked out your video, and it's packed with intriguing details—nicely done! It’s great to see the combination of high-precision optics and solid-state electronics in medical analyzers—truly a playground for sensor enthusiasts. Looking forward to diving deeper into those multi-filter mechanisms you highlighted! Keep the cool content coming.

author: oz2cpu
author_rank: Frequent Contributor
timestamp: November 24, 2024, 05:02:31 pm
content: thanks a lot for all your fantastic comments,I had so much fun making this videoso it really warm to hear you liked itI am not the only one who like special sensors :-)

author: CosteC
author_rank: Regular Contributor
timestamp: November 24, 2024, 06:36:24 pm
content: Quote from: oz2cpu on November 20, 2024, 08:09:26 amThank you for this video. I am very into sensorsI enjoyed it a lot!I participated in number of NDIR (nondispersive infrared) spectroscopy based gas sensors, so it is super interesting to see competitors design inside. I think some ideas are very nice. For full reverse engineering lot of measurements would be needed. However thermal stabilization of filters "only" surprised me a bit.Paramagnetic oxygen sensor is nice technology I never seen "inside" - I would like to see more!I think I will learn even more after reading datasheets.

author: D Straney
author_rank: Frequent Contributor
timestamp: November 29, 2024, 04:55:36 pm
content: That was fascinating, thank you! I enjoyed the combo on the second sensor of using blackbody radiation from the heater as an IR source, and then because the thermal mass makes it hard to quickly & accurately modulate the source at a reasonable frequency to eliminate DC errors (lock-in amp style), having the rotating mechanical chopper.Also never would've suspected that oxygen was paramagnetic enough to actually be detectable on a macro scale. I guess the magnets must be very strong, and that's also why that whole little mirror assembly is so tiny and well-balanced. The (comparatively) large distance between the mirror and the detectors also helps, acting as an "arc length multiplier" to translate even a small angular displacement into a detectable linear displacement.