Abstract: A sensor with a built in calibration gas source having an outer housing configured to contain one or more of the sensor elements. Within the housing is a controller configured to manage operation of the sensor and a user interface configured with one or more user input elements and one or more sensor output elements. A detector module has one or more detectors, configured to sense a calibration gas and, responsive to detection of the calibration gas, provide a detection signal to the controller. A calibration module configured to, responsive to a control signal from the controller, generate a calibration gas and present the calibration gas in proximity to one or more of the detectors. A power source is also provided and configured to provide power to the controller, the detector module, and the calibration module.

Abstract: A method, compositions and kit are set forth for detecting blood stains. A reactant solution includes fluorescin solubilized (reduced) in acetic acid in ethanol. The solution may be buffered to a pH of approximately 9. After spraying the reactant solution on the suspected area an oxidizer is applied to promote the fluorescin to fluorescein reaction with the blood. The reacted fluorescein is then detected through luminescence for capture by photography.