Photon flux measurements using calorimetry.
A simple photometric calorimeter has been constructed, consisting of a vacuum-jacketed cell equipped with flat quartz windows to admit incident light, a thermistor probe to monitor temperature change, and a resistance heater for calibration. An optically dense, photochemically inert solution inside the cell absorbs incident radiation, converting it quantitatively into heat. The calorimeter gives photon flux measurements in agreement with ferrioxalate actinometry at 366 and 436 nm. It has a sensitivity of 2x10(15) photons/s and is useful throughout the optical spectral range.
Olmsted
J
J
Department of Chemistry, California State University-Fullerton, California.