Thorzt Refractometer USG Pen While urine colour works well as a quick and easy guide, a far more accurate reading can be attained by using a Refractometer. The ATAGO Pen Refractometer is designed to measure USG (Urine Specific Gravity), being a more effective and efficient way to assess hydration status. Lighter coloured urine is more dilute (i.e. it has less molecules per volume), and has a specific gravity closer to that of water (1.00), indicating a good hydration status. Dark coloured urine results from having more molecules per volume (higher USG) and indicates dehydration. Convenient and easy to use in assessing hydration status Digital refractometer for a more accurate Urine Specific Gravity (USG) reading Delivers a nearly instantaneous result of USG Automatically calibrates itself to water and is ready to use in seconds LCD display is easily read, even with dim light With nearly a decade of research into workplace hydration and cooling, the Thorzt range is designed to assist in keeping you cool and hydrated, by promoting the bodys thermoregulation. No matter the job. Experience the hydration solution designed for hard work. Stay cool, stay hydrated!