Determination of the dynamic response of a nitric oxide detector

A chopper wheel apparatus to characterize the time response of a nitric oxi de detector is described. At low chopping rates, fast Fourier transform ana lysis of the output signal indicates that the instrument has a response tim e of about 0.45 +/- 0.14 s with respect to a periodic input signal. This de tector has an "e-folding" response time of about 0.3 +/- 0.1 s to a simple step change in input signal, demonstrating reasonable agreement within expe rimental uncertainty between the two techniques. (C) 1999 American Institut e of Physics. [S0034- 6748(99)04710-3].