Factual error: Using a Draeger tube to test for nitric acid fume, the instrument made a clicking sound. This device does not click. The bellows pump is squeezed drawing air through the tube. A reaction takes place between the air contaminant and the material in the tube causing a color change. The length of stain is proportional to the concentration.
Factual error: Nitric acid is a liquid and not a gas. The gaseous precurser is NO2 which combines with water forming nitric acid, HNO3. Neither causes instant death.