Abstract: A method and instrument capable of producing an audible tick that increases with detected gas concentrations, is suitable for indicating relatively low levels of gas concentrations, and enables the adjustment of the tick rate to provide an accurate audible indication of gas levels at higher concentrations. The method and instrument entail sensing the presence of the gas and generating an analog sensor output based on a concentration of the gas in the environment, and then processing the analog sensor output through an audio circuitry to generate therefrom an audible tick having a frequency in proportion to the analog sensor output. The processing step includes the use of an analog control loop signal to selectively increase and decrease the frequency of the audible tick.

Abstract: Systems and methods thereof for detecting at least one material in an environment prior to the environment reaching levels deemed dangerous by conventional monitors and standards includes at least one sensor adapted to measure a level of the at least one material in the environment surrounding the sensor, at least one notification device adapted to produce a signal, and a memory comprising a preprogrammed level of the at least one material in the environment. The system is programmed with a minimum notification level of the at least one material in the environment that is below the preprogrammed level and is adapted to notify a user with the signal if the level exceeds the minimum notification level. The frequency and/or amplitude of the signal is changed as the level approaches the preprogrammed level.

Abstract: A method and instrument capable of producing an audible tick that increases with detected gas concentrations, is suitable for indicating relatively low levels of gas concentrations, and enables the adjustment of the tick rate to provide an accurate audible indication of gas levels at higher concentrations. The method and instrument entail sensing the presence of the gas and generating an analog sensor output based on a concentration of the gas in the environment, and then processing the analog sensor output through an audio circuitry to generate therefrom an audible tick having a frequency in proportion to the analog sensor output. The processing step includes the use of an analog control loop signal to selectively increase and decrease the frequency of the audible tick.