Proposal of Teaching Materials for Measuring Solar Radiation Using Herbarium Bottles

—Toward the Realization of Individual Experiments for Students—

Abstract

In this paper, existing teaching materials are modified with inexpensive materials so that students can individually measure solar radiation for use in “Earth’s Heat Budget,” which is covered in the course “Basic Earth Science” in upper secondary school. Since existing teaching materials such as simple pyranometers are expensive and difficult to obtain in large quantities for use in schools, commercially available herbarium spherical glass bottles (about 400 yen each) were used as substitute materials. Water mixed with India ink was placed in the bottle and exposed to solar radiation to measure the change in water temperature, from which the amount of solar radiation could be estimated. Measurements made under clear skies in winter produced results comparable to past cases and to direct solar radiation data from the Japan Meteorological Agency, confirming the validity and utility of adopting inexpensive herbarium spherical glass bottles as an alternative teaching material.