Abstract: Apparatus for testing the operation of a carbon monoxide alarm of the type having a casing and a CO sensor extending therefrom, includes a housing sized and configured to receive the casing and to form a gas chamber in communication with the sensor, a source of CO gas, comprising a flammable substance which generates CO gas when burned, and a holder located within the housing for holding the source while the source is being burned. The CO source generates a concentration of carbon monoxide gas within the chamber which is above a pre-selected threshold for a sufficient period of time to trigger an alarm condition.

Abstract: An alerting apparatus for alerting residents to hazardous gas concentrations, comprising an alarm clock, a gas sensor, a microcontroller, and visual display and auditory speech warning means for producing a wake-up alarm and a hazardous gas warning. When the alerting apparatus detects a dangerous level of carbon monoxide, initial visual display and auditory speech warnings are provided to the user using a digital display and a voice synthesizer. The visual and speech warning messages provide the user with warnings and instructions appropriate to the concentration of gas detected and time of exposure. The user may then retrieve further visual and auditory messages which provide a detailed gas detection event history.

Abstract: An improved method and apparatus for calibrating a gas sensor which exhibits a change in electrical characteristics in response to exposure to a gas. The apparatus comprises a resistor array and a chart. The chart comprises a list of predetermined resistor combinations corresponding to a range of output levels for the sensor. The resistor array is coupled to the output of the sensor. When exposed to a gas, the sensor exhibits a change in conductivity producing an output which generates an output signal with the resistor array. The level of the output signal is measured. The measured level is then compared to predetermined values on the chart which also lists the appropriate resistor combination for each value or range of values. The resistor combination is then set as indicated by the chart.