The popular Chaipattana Aerator, Model RX-2, has been utilized in treating waste water in the water quality improvement project for more than 7 years since February 2, 1993, the day it received a patent in His Majesty�s name as a low speed surface aerator. As a result, the 2nd of February of each year was declared �Inventor�s Day�.
The Office of the Research and Development of Irrigation Equipment under the Royal Irrigation Department�s Workshop Division has carried out research and development of the Chaipattana Aerator, Model RX-2, since 1988. The aerator has since then been in experimental use at the Phra Mongkutklao Hospital and Bavornives Vihara Temple beginning in May 1989, and was given the name by His Majesty the King on May 3, 1990.