Daytime Fars fitted to VP2

I ordered this from Scaled Instruments formerly Archer Trading in Florida.

That was on 21st August and it finally arrived this morning - 10th September.

USPS took nine days just to take it the 343 miles from Jacksonville to Miami, then the customs clearance here was almost as slow.

I followed it easily on the USPS and Parcelforce online tracking, and it arrived in good condition.

Buying from the US worked out about £25 cheaper than UK sellers after VAT was paid.

The concept is that in some conditions the temperature inside the white louvred sensor housing can get too high - in particular days with little wind and early/late in the day there is some evidence it can read as much as 3C too high.

This would rarely affect the day's maximum, but it's nice to have more accuracy if possible.

The kit includes the revised upside down mount for the sensor.

This keeps it drier and might prolong its life (quite an expensive one to replace).

Fitting it was mostly common sense - but rather fiddly and the instructions were somewhat unclear about some details.

After doing the first one while referring to the instructions, a second one it would be 30 minutes work! It took almost an hour from taking the ISS down to up and running again.
By that time the sun had set so it wasn't running, but I did test it earlier.
It is practically silent so will be hard to know if it is working or not!

The main difference visually is that it comes with a new front panel with dual solar cells - which appear identical.
You re-use all the original plastic parts and most of the screws and bolts.

Update 11th September.
The fan could be heard humming quietly and with light winds it was surprising how much air you can feel being blown out of the screen above the thermometer sensor,

I thought I'd put the standby Vantage Vue up alongside the VP2 this afternoon.

It was warm and sunny with light easterly winds under 4mph.

At about 5pm the Vue read 0.9C higher than the VP2.

Soon after sunset the difference was more like 0.3C

It's hard to say how much of this discrepancy is relates to the FARS and how much the larger VP2 enclosure.

The significant thing is that the difference changes as the sun warmth hitting the side of the shield varies.

I'll leave both up for another day or so and see how they change in different conditions.
Unfortunately since I only have one data logger I can't do a comparative graph easily.