Micro-Thermic Measurements in Arctic Vegetation with a Transistor-Probe and Integrating Cu-Voltameter

Abstract

A description is given of the circuit and construction of a portable, inexpensive instrument developed for measuring and recording mean temperatures over long periods. The probe consists of a Germanium-transistor of small dimensions. The 0-current, being a logarithmic function of temperature, is amplified in a Siliciumtransistor and integrated in a Cu-voltameter. The method employed in calibration and in calculating integral and mean temperature is explained. Ten instruments were placed in the bottom layer in different types of vegetation in South West Greenland in the period from 5./6.7.-20.8. 1965. Beside of 6 of the instruments liquid thermometers were placed for measuring daily maximum and minimum temperatures. An assessment of the uncertainties of measurements of mean temperatures by the instruments shows that the temperature usually can be recorded with an error of ?0.2-0.40C. The investigations showed that the highest mean temperature in the period, 37.20C, and the highest maximum temperature, 57.00C, were measured at the same locality, viz. in an open scrub on a dry slope with southern exposure, while the lowest mean temperature, 17.00C, and the lowest maximum temperature, 32.00C, were measured at a locality in a moor near a small brook. It is concluded that the instrument developed is suitable for measuring microclimatic mean temperatures over long periods in nature. The investigations have shown that even in arctic vegetation rather high micro-climatic temperatures may occur in the period of growth. Pe3IoMe