Investigation of the properties of an optothermal detector

An optothermal detector with a pyroelectric sensitive element is described. Estimates are given of the limits of applicability of this device and its performance compared with the spectrophone. The dependences of the absorption coefficient of formaldehyde CH₂O on its pressure and that of the buffer gas, determined experimentally at the P_12–11 (17) CO line wavelength, are discussed. It is shown that the device can be used at low pressures of the investigated gas.