Oxygen scavengers are added to remove residual dissolved oxygen that can cause corrosion in steam generating equipment. It is important that levels of oxygen scavengers be routinely checked to prevent corrosion and ensure that equipment is working efficiently. In addition to boilers and cooling towers, process steam has important applications in food, beverage, and pharmaceutical production.

The HI96773-03 are high quality reagents that are pre-measured, allowing for users to achieve fast and accurate colorimetric measurements. These reagents use an adaptation of the iron reduction method. In the presence of oxygen scavengers, ferric ions (Fe3+) are reduced to ferrous ions (Fe2+). The iron (II) ions then react with a triazine derivative (PDT disulfonate) to form a violet colored complex. The color of which can be measured colorimetrically to determine the concentration of the oxygen scavenger. The methods used by Hanna Meters for the different types of oxygen scavengers all use the same reagents and procedure. The meter uses a mathematical formula to express the results of the test in the appropriate units. The results can be displayed as DEHA, carbohydrazide, hydroquinone, or ISO-ascorbic acid in mg/L (ppb) or mg/L (ppm) depending on the method used.