The study of aldehyde photochemistry with the spectrophone technique

Simple sample cell for examination of solids and liquids by photoacoustic spectroscopy

“…The photoacoustic effect has been used for many years to study relaxation phenomena in the gas phase (1)(2)(3). In 1973, Harshbarger and Robin (4) and Rosencwaig (5) published results of experiments investigating the optical properties of solids, which demonstrated the qualitative similarity between the solid photoacoustic absorption spectrum and the conventional solution optical absorption spectrum of certain samples.…”

Digital simulation of temperature and pressure effects in photoacoustic spectroscopy

“…h = he-01 (2) where Ix = intensity at the point x (watts/cm2); 10 = light intensity at the sample surface; ß = absorptivity or absorption coefficient of the transition (cm-1); x = perpendicular distance from the sample surface (cm). For very small changes in x, Equation 2 can be differentiated to give dIx = ~ß ^ (3) which can be written directly in finite difference form AIX = -/3/0e",lz Ax (4) This linearized approximation agrees to within 5% of the exact form when ß /2 < 0.3.…”

“…The photoacoustic effect has been used since the 1940's to study relaxation phenomena in the gas phase (1)(2)(3). In 1973, experimental results were published (4,5) demonstrating the qualitative similarity between the usual optical absorption and photoacoustic spectra of certain solid samples.…”

The calorimetric detection of excited states

“…The work of deGroot et al [ 24 ] illustrates the use of the acoustic spectrophone to study photochemical processes of acetaldehyde. These authors find that at pressures below a few torr the optoacoustic spectrum in the region 230–360 nm resembles the normal absorption spectrum of the compound.…”