How to convert µm to µg? Molecular mass of ultra fine particulates?

[adrelanos grayson]

I have an laser egg by origins. (Didn't know AQE exists until now.)

It can show >0.3µm and >2.5µm readings.

Is it possible to convert µm to µg? I imagine it would only be an estimate, but that is fine.

Or asking the other way around, what is the average molecular mass of ultra fine particulates?

[Victor Aprea]

Adrelanos,

I don't quite understand what µm would mean in this context? Is it reporting a count of particles that are greater in diameter than 0.3µm and greater than 2.5µm respectively? If so you would need to make an estimate of the average massiveness of those particles to multiply those counts by, and I don't think that's trivial to do. I know that Origins product (which has absolutely no association to our product in case that's not clear) has gotten a lot of publicity lately. Does it live up to the hype?

In Air Quality Egg, we measure the voltage from the PPD60PV, and establish the baseline voltage reported by the sensor in HEPA filtered air, then apply a transformation to the voltage, based on the datasheet, after removing this offset. I'd like to at some point figure out how to expose these to a known high concentration (below saturation) so that we can include a span calibration in addition to the zero calibration we do today. 

Kind Regards,

Vic

Victor Aprea // Wicked Device

victor...@wickeddevice.com

T: @vicatcu

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[adrelanos grayson]

On Wednesday, June 15, 2016 at 2:55:33 AM UTC+2, vicatcu wrote:
> I don't quite understand what µm would mean in this context? Is it reporting a count of particles that are greater in diameter than 0.3µm and greater than 2.5µm respectively?

Yes. Technical specs says it measures from 0.3µm to. 10µm. The display has particle counters for >0.3µm and >2.5µm. I believe that is µm/m3.

> If so you would need to make an estimate of the average massiveness of those particles to multiply those counts by, and I don't think that's trivial to do.

Hence, I am asking. =)

But never mind. I missed in the menu that it does feature an PM2.5 µg/m3 counter.

> I know that Origins product (which has absolutely no association to our product in case that's not clear) has gotten a lot of publicity lately.

Yes, I understand.

> Does it live up to the hype?

It's a big rough in the edges so to speak. The android app was very difficult to set up. I was confused, it only supports wifi with 2.4 ghz, not 5 ghz. It found the 5 ghz network, but then failed to connect. There are several ways to set up a connection with the phone. With the first one I run into a state where the app would no longer start without instantly terminating. To fix that, I needed to re-install the app. I got it to work eventually with a different connection mode. The app is also not installable from the android app store and needs to be manually downloaded.

Anyhow. With app or without. After having found the PM2.5 µg/m3 counter, my second impression is, that it will be sufficient to do its job. Given being the cheapest offer I found on consumer grade air quality particle counter devices, it's okay.

[Xanthe Matychak]

Thanks for sharing your feedback Adrelanos. 

I'm curious about their customer support. Did you try asking them these questions? How did they respond?

Xanthe Matychak

Ithaca, NY

makebetterstuff.org

http://faculty.ithaca.edu/xmatychak/

[Dirk Swart]

Hi Adrelanos,

It does not sound like you are using an Air Quality Egg (airqualityegg.com). Can you confirm this?

Thanks

Dirk

On Tue, Jun 14, 2016 at 6:00 PM, adrelanos grayson <adre...@gmail.com> wrote:

[adrelanos grayson]

On Wednesday, June 15, 2016 at 2:26:52 PM UTC+2, Dirk wrote:
> It does not sound like you are using an Air Quality Egg (airqualityegg.com). Can you confirm this?

Already mentioned this in my first post.

[adrelanos grayson]

On Wednesday, June 15, 2016 at 12:49:26 PM UTC+2, Xanthe Matychak wrote:
> Thanks for sharing your feedback Adrelanos. 
>
>
> I'm curious about their customer support. Did you try asking them these questions? How did they respond?

I asked. I guess they were confused by my questions. Explained that mg cannot be converted to µg. But however did not mention it has PM2.5 µg/m3 integrated.

I have not reported yet the android app issues as in my experience this can be tedious and futile. If it was Libre Software and a public bug report I might be more motivated.

[adrelanos grayson]

On Wednesday, June 15, 2016 at 11:33:53 PM UTC+2, adrelanos grayson wrote:
> On Wednesday, June 15, 2016 at 12:49:26 PM UTC+2, Xanthe Matychak wrote:
> > Thanks for sharing your feedback Adrelanos. 
> >
> >
> > I'm curious about their customer support. Did you try asking them these questions? How did they respond?
>
> I asked. I guess they were confused by my questions. Explained that mg cannot be converted to µg. But however did not mention it has PM2.5 µg/m3 integrated.

They answered again. Correction: their particle counters count particles in 0.1L of air. And explained it also has PM2.5 µg/m3 integrated.

[Victor Aprea]

... " it also has PM2.5 µg/m3 integrated" -- whatever that means ;-). The "beauty" of opaque (closed-source) products is they can say whatever they, and you just have to take them at their word. 

Vic

Victor Aprea // Wicked Device

victor...@wickeddevice.com

T: @vicatcu