HI-749-11 is a high-quality set of calibration standards that allows users to validate the Chromium VI Low Range Checker®HC – HI-749. The HI-749-11 includes one sealed cuvette for zero ppb chromium VI and one cuvette that is tinted to an equivalent 100 +/- 5 ppb chromium VI sample @ 25°C. The calibration check set is produced using reagent grade chemicals in a temperature controlled environment.