A multi-
station RF
thermometer and alarm
system measures temperatures and / or percent
relative humidity at remote locations by RF weather stations, and displays received temperature and / or other
weather data telemetry on a multi-
station base station that provides out-of-bounds
alarm signal indications whenever temperatures are outside of user-selectable minimum and maximum values. Randomized transmission times in one embodiment and two-phase unique transmission schedules in another lessen the possibility of on-going collisions between two or more transmitters contending for the
base station at the same time. Redundant
data transmission lessens the possibility of
environmental noise interference. The redundant data, transmitted at random times in one embodiment, includes a unique channel ID code, house-keeping data, the current temperature and / or time-to-next-transmission data, and in another embodiment, transmitted at uniquely prescheduled times of two-phase transmission schedules, includes
station location ID and
transmission schedule phase. The
weather parameter sensing transmitters operate at a low
duty cycle with low
peak current consumption resulting in long battery life. The multi-station
base station may be AC- or battery-powered. Channel and station ID switches are provided on the remote
temperature sensing transmitters and on the multi-station base station in one embodiment and a station ID number selection switch is provided in another
transmitter embodiment.