Monochloramine is expressed in parts per million (ppm) or milligrams per liter (mg/L) which is a weight concentration of the analyte. On the 5500 AMC, the results can be displayed as either N or CL₂ which is how many milligrams of monochloramine are in a liter of sample as equivalent to milligrams of N or CL₂.
The weight ratio between these main species is the molecular weight of CL₂ divided by atomic weight of N (71/14 = 5.07). This ratio represents the reaction of monochloramine formation, which takes one molecule, or mole, of chlorine and one atom of nitrogen as contained in one mole of ammonia. In other words, the molar ratio is 1:1, but the weight ratio is approximately 5:1. Therefore, this coefficient (5.07) is used by AMC to convert concentration of monochloramine expressed as N into CL₂.It is the end user’s choice as to how they would like the results expressed. Expressing the results as CL₂ can help with ease of comparison to a chlorine analyzer such as the CL17. If the results on the 5500 AMC must be expressed as N, the result provided by the 5500 AMC must be multiplied by 5.07 in order to accurately compare results to a chlorine analyzer.