The paper presents the results of investigations relating to the utilization of resistor sensors in synchronic measurements of air temperature. The data come from an experimental field located in the Forest Division of Wisła, Beskid Śląski Mts. The analysis comprised the valuation of a few elements. The first of them concerned the control and conversion efficiency of the microcontroller set. The second concerned the values of dynamic errors in different types of measuring equipments. The last one concerned the investigation of the dependence of automatic and manual temperature measurements. The results of this study showed the dominant role of temperature measurements precision, fulfilled the time constant of thermometer and testing period. It is possible to reduce the error resulting from the different thermal inertia of the electric and fluid thermometers below value of 0.02oC. The occurrence probability of dynamic errors in the whole range of air temperature is 1. The differences between the liquid and electric thermometer indications resulting from different thermal inertia were 0.018oC on average in stagnation and 0.25oC in quick changing air temperature conditions. The change of measurement method of air temperature from manual to automatic does not need to break the homogeneity of climatologic series.