Watchman Oil tank monitors
Frequency : 433.92 Mhz
Modulation : FM
Tx interval : 15min
Patent coverage : GB2318696, GB2302178 and GB2303920
Receiver
"The receiving end has a generic UHF data receiver probably same as used
everywhere. This then feeds into a PIC chip (surface mounted). This drives a single digit LCD display. Also has a dual op amp and a voltage regulator."
"The Watchman cannot be received for two reasons. The modulation is FM while RFXCOM is AM. And the transmission protocol is not available in the receiver.
In general, no other 433.92MHz sensors can be received than the listed sensors."