Abstract: In electronic alarm apparatus for monitoring the presence or absence of objects within a given area, a transmitter attachable to an object, a shift register for storing a digital identification code, and an electronic circuit including a time delay circuit for periodically transmitting the digital identification code as a radio frequency signal; a monitor including a logic timing circuit for activating a receiver for receiving the radio frequency signal, a check circuit for comparing the received signal with a stored identification code and audio logic circuit and liquid crystal display for providing audio and visual indications upon failure of receiving a given number of consecutive transmissions from a given transmitter; the transmitter further including tamper switch and tamper flag logic circuit for changing the digital identification code stored in the shift register upon premature removal of the transmitter from the object.