Wind velocity, direction, and temperatures can vary drastically before, during, and after wild or prescribed fires. A data-recording system based on the logarithmic character of semiconductors has been developed for observing turbulent fluctuations from the mean in ratio form. The system combines a recorder, discriminator, amplifier, thermocouple, and anemometer. It has been satisfactorily field tested under severe ambient and fire conditions. This method can also be used to record and determine mixing ratios in turbulent areas for air quality studies.