Recent comments in /f/gadgets

PacoTaco321 t1_jcgmdfa wrote

Reply to comment by Tactically_Fat in Open-source tool from MIT’s Senseable City Lab lets people check air quality, cheaply. by chrisdh79

So does the default weather app on my phone. I'm not sure why someone would need their own meter when there's so many ways to do so already. If you are in a situation that you have to worry about checking air quality in a highly localized area, you should probably just avoid being there altogether.

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hazpat t1_jcghwce wrote

Reply to comment by Tactically_Fat in Open-source tool from MIT’s Senseable City Lab lets people check air quality, cheaply. by chrisdh79

Flow meters are usualy built in and auto adjust. Checking flow with a rotometer is fast and simple.

Most meters operate under factory calibration factors that are acceptable under most conditions. You can, but are not required by any regs, to set user calibration factors based on local conditions. This is a very tedious process that you don't typically see people do unless they are in abnormal conditions like constant fog or whatever. On my meters temp and pressure sensors are built in, no idea about the purple, but I would trust the particulate data if it passed a flow and zero check.

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Tactically_Fat t1_jcgfe5y wrote

Reply to comment by Maktube in Open-source tool from MIT’s Senseable City Lab lets people check air quality, cheaply. by chrisdh79

Some things can be an excellent supplement - but when purple air readings are way off from properly calibrated, maintained, and audited Federal Equivalency Methods or Federal Reference Methods instruments - they leave a LOT to be desired. A lot.

ETA: things that involve moving air at rates that are supposed to be constant - and/or able to compensate for changing atmospheric conditions aren't quite the same as solid-state temperature sensors, rain gauges, or even wind vanes.

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Tactically_Fat t1_jcgf4ya wrote

Reply to comment by hazpat in Open-source tool from MIT’s Senseable City Lab lets people check air quality, cheaply. by chrisdh79

Need to be able to audit flow.

And flow is related to temperature and pressure.

Agreed that a simple leak check can be peformed with a HEPA filter.

PM samplers that can/have met Federal Equivalency Methods status are all able to be calibrated to atmospheric conditions as well as having these things audited / verified.

A lot of this is done so that the data generated can be defensible should the need arise.

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oakteaphone t1_jcgejap wrote

Reply to comment by MoirasPurpleOrb in Open-source tool from MIT’s Senseable City Lab lets people check air quality, cheaply. by chrisdh79

>it’s not like I can adjust my day based on the quality of the air around me.

It's actually commonly done in parts of the world. I was occasionally wearing masks for more than a year before the pandemic.

And that's the solution. Reduce outdoor activity where possible (especially exercise), keep windows closed, and wear a mask if you must go out.

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hazpat t1_jcgdz3o wrote

Reply to comment by Tactically_Fat in Open-source tool from MIT’s Senseable City Lab lets people check air quality, cheaply. by chrisdh79

I would believe they can be tested in a very similar matter to professional sensors. My top of the line detectors are just calibrated to zero, which i assume is extremely easy to do on the purple. You simply apply a filter and make sure levels drop to 0. There are no mid range calibration for particulate matter. It is nearly impossible to produce a standard concentration aerosol.

Now if it is also testing for gasses or vapors, it would need to be calibrated with standards

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IamAkevinJames t1_jcgdoxv wrote

Reply to Absurd RTX 4070 MSRP reportedly 50% more vs RTX 3070 as leak points to AIB models entering RTX 4070 Ti territory by diacewrb

Like are any of us surprised? Never more at least in the near future will I buy new. The second hand market is again ripe. I just upgraded to a 3060 12GB V1. If I build a new system it will probably be all blue or red and absolutely no green. Wake the fuck up Nvidia the majority of gamers are not rich by any means.

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Maktube t1_jcgd3lr wrote

Reply to comment by Tactically_Fat in Open-source tool from MIT’s Senseable City Lab lets people check air quality, cheaply. by chrisdh79

They're not really accurate to the extent that you'd want the government basing health-related decisions on their readings (I'm not sure any crowd-sourced thing could be reliable enough, either), but they're fantastic for what they are, which is 1, widely distributed and 2, consistent.

Kind of like citizen weather stations, they're not a replacement for the government data, but they're an excellent supplement to it.

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iamnotazombie44 t1_jcgak77 wrote

Reply to comment by 3226 in Open-source tool from MIT’s Senseable City Lab lets people check air quality, cheaply. by chrisdh79

This is all tragically true. I'm a chemist from across the country and I was crying for those people and that area the day I read the manifest. That area is fucked.

I wanted to report that you can detect these compounds an organo-halide detector, they are relatively cheap sensors to detect refrigerants. They work on detecting the X - C bond, where X is F, Cl, Be, or I.

It's a pretty common for refrigeration people and in water testing. They are not cheap, but not prohibitive either.

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a_a_ronc t1_jcg9usu wrote

Reply to comment by GeoAtreides in Open-source tool from MIT’s Senseable City Lab lets people check air quality, cheaply. by chrisdh79

Yeah I was looking at their assembly doc on my phone and saw it there, so just think they forgot it.

I’ll have to check out those Bosch sensors. I wanted to measure VOCs getting kicked off of resin 3D printers so was mostly just looking at full solution when I last looked.

EDIT: They responded on GitHub already. It’s listed in a separate tab of the BOM. So yeah, just an SPS30 and Bosch BME280

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