a followup on light measurement

[Greg Troxel]

I'm writing a new message since the list is wackily rejecting mail.


Total light is an interesting concept, and it is not clear that it makes
sense.

One could measure an energy flavor of illuminance and thus the units
would be lux-s or lux-hours. However, lux is a perceptual unit across
wavelength, and that raises the question as to how 1 lux for an hour
compares to 3600 lux for 1s and then total darkness the rest of the
hour. That's extreme, but still.

One could also integrate a radiometric measurement, taking W/m^2 and
ending up with J/m^2. This makes clearer physical sense.

I am curious what the conceptual basis and rationale is for what Acurite
is graphing. I'm not saying it doesn't make sense, just that it
immediately seems very tricky.

[Colin Larsen]

This may or may not be pertinent from the Ecowitt driver wiki

https://github.com/gjr80/weewx-gw1000/wiki/Understanding-Ecowitt-LAN-Wi-Fi-Gateway-API-radiation-fields

Colin

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[Greg Troxel]

Colin Larsen <colin....@gmail.com> writes:

> This may or may not be pertinent from the Ecowitt driver wiki
>
> https://github.com/gjr80/weewx-gw1000/wiki/Understanding-Ecowitt-LAN-Wi-Fi-Gateway-API-radiation-fields

Super relevant. That all looks great.

The only thing I would add is that it is a bug in the extended wview
schema to use the word "luminosity". The proper term is "illuminance".
But that is the world in which we live in; the schema uses luminosity.

That ranted, the page is very clear that illuminance in lux is stored in
the luminosity field.

The OP is highly likely storing illuminance values in the radiation field.

[gjr80]

On Saturday, 2 September 2023 at 10:48:32 UTC+10 Greg Troxel wrote:

The only thing I would add is that it is a bug in the extended wview
schema to use the word "luminosity". The proper term is "illuminance".
But that is the world in which we live in; the schema uses luminosity.

This discussion was had with Tom some time ago, and whilst the discrepancy is acknowledged, the impact on users of making the necessary changes was considered too great and we decided to live with things as they are.

 

Gary