A device for providing a calibration fluid, in particular a nitrogen oxide, for calibrating a respiratory gas analysis device, includes a first interface for connecting a chamber of the device to a measurement path of the respiratory gas analysis device, a first opening for introducing a reactant carrier with a first reactant into the chamber, and a contact element. The contact element is arranged in the chamber relative to the first opening such that when the reactant carrier is introduced, a contact of the contact element with the reactant carrier is facilitated in order to trigger a chemical reaction of the first reactant so as to generate the calibration fluid. The disclosure further relates to a system, a reactant carrier, and a method for providing a calibration fluid for calibrating a respiratory gas analysis device.
