The objective of this research was to produce prototype of an early warning system based on SMS for detection the rising level of ammonia gas in wastewater treatment of leather tanning industry. The systems consist of three parts. those were data input. data processing. https://www.roneverhart.com/Fire-Retardant-Premium-Polyester-8ft-Rectangular-Tablecloth-Ivory-Fitted-High-Performance-Table-Cover/