Has a response time of 60 seconds allows this to be a good head to find high ozone levels, and measure ozone levels in spaces where testing may be occurring. Designed to be used with the Aeroqual S-500 portable monitor. The Aeroqual Sensors are housed within an interchangeable ‘sensor head’ that attaches to the Aeroqual S500 Portable Air Quality Monitor base. You can choose from up to 30 different sensor heads. Each sensor contains a single gas or particle sensor. Swapping sensor heads takes seconds and no configuration or re-calibration is required.