The personal gas detectors Pac 6000 and 6500 measure a specific gas quickly and accurately. User-friendliness is enhanced by a speech-free display, clear color coding, and a robust, grippy housing. They feature a triple alarm: acoustic, visual, and via vibration. The sensor response times are quick even under harsh conditions. Measurement and direct display are provided for one of the following gases: CO (carbon monoxide), H2S (hydrogen sulfide), SO2 (sulfur dioxide), or O2 (oxygen). The devices are time-limited to two years after the first activation.