Recently I have noticed that the reading on my solar panel is incorrect. On recent nights when it has been cold outside it is reading 12/13degC whereas the air temperature can be no more that 3/4deg. I measured the resistance going into the panel and it corresponded to a temperature of 12deg (1046Ohm) so the panel doesn't seem to be the problem (although it does intermittently read temperatures exceeding 120deg...), There are 2 joints in the cable coming back to the panel and I measured the resistance at each of these points as approx 1046Ohm so it appears that the problem is with the PT1000 sensor itself.
I am going to order a new PT1000 cable but want to ensure that there would be no issues with what I order. Do all cables have standard connectors? Is it a simple task to replace the sensor? I am going to try to order a 10m long cable if possible to remove at least one of the joints.
Also. looking at the piping a lot of the insulatation surrounding the solar pipes has pulled away from the system so I need to fix this as well. Are there good online suppliers of this insulation - I presume it needs to be special high temperature insulation?