The Phosphorus Ultra Low-Range Checker® HC Calibration Check Set - HI736-11 provides a simple solution to validating the Phosphorus Ultra Low-Range Checker® HC - HI736 that has a range of 0 to 200 ppb as phosphorus. This high-quality set of standards is manufactured in our state-of-the-art facility and comes supplied with a Certificate of Analysis. The Certificate of Analysis provides the lot number, reference values and expiration date for traceability when certifying the Checker® HC.