ACTIVITY MONITORING DEVICES

Active/Inactive Activity gives a "yes/no" indication of activity. Active/Inactive transmitters contain a microprocessor, actually a microcontroller device that is programmed to switch pulse modes when activity is sensed. The sensor used is a tiny mercury switch that opens and closes the input to the microcontroller circuit when it senses motion.

Unlike the older style pulse-rate based activity and mortality monitors, the pulse rate of the output signal does not change. The pulse mode changes from a single to a dual pulse burst mode, indicating activity or absence of activity. Change in pulse burst mode means a change from the traditional beep beep beep signal to a double pulse burst mode: bibeep bibeep bibeep. The active or inactive mode can be programmed to be indicated by either the single or double pulse burst mode. The choice of the indicator pulse should be determined by the state in which the study animal exists the most frequently. For instance, if the animal is quiescent most of the time, the single pulse burst should be chosen to indicate this, as it draws less current than the double pulse burst mode.