Topic: AC Case fan for 24 HR Davis FARS shield mod recommendation requests

[fkapp]

Maybe sht bad?

[CW2274]

Nope.

[CW2274]

As I scrutinize your obs further, I really don't see any problem on your end, none. The graduations are fine. Perhaps Meso's jacked or your neighbors are really jacked. Up to you to find out.

[fkapp]

Thanks. Was a strange evening with calm winds to start and quick falling Temps.  Then winds picked up sw off lake Erie and shot temp up 9 degrees in a little over hr.  Could be just function of quicker response time.
Will enjoy and see how goes over larger sample over long run.

Thanks again
Frank

[azchrisf]

Yeah those spikes are not from the fan moving too much air it's something else. Did sprinklers or something come on?

[fkapp]

Hi. No sprinklers here this time of year as is fall up in Buffalo, NY.   Thanks for suggestion.
Will keep eye on it and see if happens again this evening when sun sets.

[ValentineWeather]

The welded core with open plates works best with FARS. They really aren't that expensive without the electronics attached.  I've tried the open core Dfars and it doesn't work as well being wide open.  On the inlet screencap, you can cover it with filter material and slip it back on. I use silk 100 thread and leave the filter off the sensor. I don't know if it's needed but have always used the insulator too.

Scaled has an exploited view of what is needed.  Of course, you don't want anything to do with solar or batteries.
 
https://www.scaledinstruments.com/wp-content/uploads/2020/12/24hr_fars_Exploded_Diagram.pdf

Here is the welded core. On backorder, it looks like: https://www.scaledinstruments.com/shop/davis-instruments/parts/vantage-pro2-parts/radiation-shield-parts/davis-7345-029-vantage-pro2-24-hr-spars-welded-core/

[fkapp]

Thanks, I used that schematic from Scaled and that is the setup I have (less solar panel and batteries).
May use solar in the summer to avoid extension cord across yard when mowing but that is for another day.

Agree not sure if need the insulator, but installed as diagram called for.
Figured with moving air and the open plates already had plenty of insulation so interesting you mentioned.
Would be curious if anyone is running without the insulator?

[ValentineWeather]

Thanks, I used that schematic from Scaled and that is the setup I have (less solar panel and batteries).
May use solar in the summer to avoid extension cord across yard when mowing but that is for another day.

Agree not sure if need the insulator, but installed as diagram called for.
Figured with moving air and the open plates already had plenty of insulation so interesting you mentioned.
Would be curious if anyone is running without the insulator?

Oh good, I thought by post #26 this was a dfars and was saying oh no.

[jerryg]

You need the insulator, look at the inside and it has ridges that create an air gap between the sensor housing and the insulator, it is another air intake tube that scrubs any heat away from the sensor chamber.

[CW2274]

Would be curious if anyone is running without the insulator?

Agree with Jerry. The insulator is there for a reason. Just as an FYI, the 24hr shield is patented so I figure they know what they're doing.

[ValentineWeather]

That's right Jerry forgot about that. Another area to scrub heat away from the sensor is the air gap around the insulator.

[fkapp]

Thanks guys for explaining the mechanics of the shield.
I am very happy with the way been running so far.
Much calmer wind day today with mix of sun and clouds throughout the day.
Has been very stable temp throughout.
I have the SF2 Cap installed as have since setup station 2 years ago.

Few more quality suspect points today on Mesowest because of dewpoint variance again today, but am starting to suspect is function of data quality around me.
Not going to worry about it as know am running shield to build specs 

Thanks again
Frank

[CW2274]

Not going to worry about it as know am running shield to build specs 

Good. QC is a tool, not an end-all-be-all. Nobody knows your data better than you.