Abstract:
The cosmic radiation intensity-time variation at latitude 13° 46’(N) was investigated by using an I.G.Y. Standard type neutron monitor with 3 BF₃ counters which was constructed at the Physics building of Chulalongkorn University. Most of detection systems are transistorized circuits. The pile has been running continuously since December 21, 1967. The interval of the counting is recorded every 15 minutes, and the bi-hourly values are reported. All the counting rates are pressure corrected to 757 mm of Hg. The diurnal variation shows that the intensity in the daytime is more than that at night. The intensity measured is about 1255 ± 59.5 counts/hour.
