If your RF500 System Transmitter is recording and showing data readings that are erroneous and which are not related to the environment where they are measuring the temperature i.e. 56⁰C in a fridge or cold store, then we would initially suggest double-checking any connected probes, swapping them out for known good probes if appropriate.
If the Transmitter in question just has an integral sensor (RF513) or the connected probes have all been tested on other devices and found to be working OK, then you will need to contact us, as your Transmitter could be faulty.