River water quality is assessed by the Environment Agency through the General Quality Assessment scheme. Continuous monitoring of ammonia in river water is important for plant operations and environmental agencies. When river temperatures change, ionized ammonia changes to un-ionized ammonia gas which can be fatal to fish and other water organisms.
Water quality is also important for water treatment plants using river water as the water source. High ammonia levels in the inlet water cause major problems in the disinfection process and can cause the inlet to be closed.
The Q45N Dissolved Ammonia Monitor converts ammonia to a stable monochloramine compound, equivalent in concentration to the original ammonia level. The chloramine concentration is measured with a polarographic membraned sensor that selectively responds linearly to chloramines. The reaction chemistry gives the Q45N Dissolved Ammonia Monitor excellent sensitivity even at very low (ppb) ammonia levels.
Reagents are simple and inexpensive and their usage is low. The Q45N Dissolved Ammonia Monitor has two 4-20mA outputs programmable for free ammonia, total ammonia and monochloramine concentration, all measurable on the same instrument.