The Alarm Module is intended for use with the SmartReader Plus line of data loggers. It utilizes the alarm dial-out capability of the SmartReader Plus data loggers, providing a blinking LED light and audio beeper to indicate that an alarm threshold has been tripped. The Alarm Module stays in alarm state until the reset button has been pressed. Additionally, two sets of relay contacts are provided for general purpose use. The Alarm Module can be used with a single data logger or with a network of data loggers. External power supply is required.