Instrumentation for recording microclimatological factors

Abstract

The objectives, means, and some of the results of intensive studies of the thermal aspects of microclimatological environment are discussed. The proposed Table 1 of weather types is believed in general to combine rather effectively the European classification, depending on air mass, and the American description by cloud cover. The latter is the more specific for insolation, but the former is most significant for nocturnal heat rates, for moisture, and for air “quality.” The special instrumentation described has been developed in studies of heat transfer from animals and plants, particularly for measuring conduction and radiation. Such electric sensing elements seem to have use in the overall measurement of agricultural climatic environment. The recording potentiometers needed for the micro studies made possible the automatic recording of all the regular weather‐station observations described. It is hoped that discussion will lead to some general agreement on minimum instrumentation. Any such agreement would encourage the establishment of many more environment stations and constitute an important step from qualitative toward quantitative experiments. Examples of the usefulness of the instrumentation are described and a heat balance between solar and sky radiation and the ground is discussed. With adequate understanding of heat balance, we believe that agricultural research findings at one station can be extended to other areas of somewhat different climate.

Flight activity ofColias philodice eurythemeBoisduval in response to its physical environment

“…by 6:00 p.m. These values are comparable with those for the Imperial Valley illustrated by Brooks and Kelly (1951), who also made comparisons with ground radiosity and net heat absorbed by the ground. The only significant influ ence of season on the total solar and sky radiation intensity curve is a change in its period, which is greatest during midsummer when the days are longest, and shorter in the spring and fall when the days are shorter.…”

Conductivity and length relationships in heat‐flow transducer performance

“…Since that time transducers of the type described by Dunkle have been used by many investigators. Reference may be made, for example, to Brooks and Kelly [1951], Gtrhardt [1957], Portman [1957], and Rhoades {mil Heat-flow transducers have been used for many "ther purposes, particularly for measuring heat transfer in building walls. They might be used, as well, in dams and other hydrological structures wherever it is desired to measure heat transfer.…”

A field installation for automatic recording of micro‐environmental gradients

“…Heat intensity or solar radiation may be determined by a type-DW-68 General Electric total radiation meter; light, by several kinds of photometers reading up to 20,000 foot candles intensity; air movement, especially convection currents and movement in small places, by a type-8500 thermoanemometer with a one-quarter inch diameter probe made by Illinois Testing Laboratories; humidity, by a type-7000U Dewpointer, also by Illinois Testing Laboratories; and temperature by various sensing elements, including 0.4 mm diameter thermistor beads for either contact or small area measurements. Additional instruments, as for example, those which better indicate heat flow conditions in the environment, may be added as needed [Brooks and Kelly, 1951].…”