RADIATION SHIELD CLEANING AND FAN REPLACEMENT
In August 2014 it was noticed that temperature readings on hot sunny days were 1 or 2 degrees higher than other stations in the area.
It was discovered that the fan was no longer working so I ordered and fitted a replacement fan, and also replaced the rechargeable batteries.
Replacement fan with instructions, and new rechargeable batteries ready for installation.
Rain cone removed and tipping spoons taped down to avoid false readings from vibration/knocks.
Old fan and guard removed, plus protective anti-insect mesh from underneath the FARS.
Temperature/humidity sensor removed and solar panel cable disconnected and FARS taken down for cleaning.
Dirty shield plates separated from main FARS unit, plus dead batteries removed.
Each plate cleaned separately - they were filthy.
After cleaning - FARS reassembled with new fan and rechargeable batteries.
FARS reattached and sensor/solar panel reconnected - all done until the next time :)
FAN MOTOR REPLACEMENT
During September 2015 I discovered temperatures again reading too high on sunny days. The fan was not spinning and tapping the pole would start it but on the next sunny day it would be stopped again. Rather than spend a lot of money on another fan assembly so soon after the last replacement I decided to purchase a couple of motors from Maplin and replace the failing one.
It was quite tricky chipping out the glue to remove the old motor but managed in the end, and the new motor is just packed in place with tissue! It is working fine and will see how long it lasts!!!
Second Maplin motor fitted on 04/07/2017 to replace the first as it started failing 18 months after fitting and gave up completely in a recent heatwave. Hopefully this will be ok now for a year or two.
On 11/05/2019 I attempted to fit a new Davis fan assembly in the radiation shield, but due to age and corrosion a connection pin broke on the PCB for charging from the solar panel, and I couldn't repair by soldering, so I ordered a special cable to directly connect the solar connection to the fan connection and that was fitted on 15/05/2019 and fan works fine now so is a daytime FARS only.
Old Davis motor on the left and new Maplin motor on the right.