PHOTOPYROELECTRIC DETECTION OF ORGANIC VAPORS

The photopyroelectric (PPE) detection of vapors under ambient conditio ns is demonstrated. A polymer film coated on the transducer is used as sensitive layer. Sorption within this layer binds and concentrates th e vapor molecules at the detector surface. Monochromatic IR-radiation selectively excites the sorbed molecules and, therefore, the detected heat is a function of vapor concentration. Preliminary experiments yie ld a detection limit of 30 ppm methanol vapor.