Final answer:
To obtain urine specific gravity (USG), one must collect a fresh urine sample, mix it, measure the specific gravity with a refractometer, and then record the result.
Step-by-step explanation:
To obtain a urine specific gravity (USG), the correct step-by-step process is:
- Collect a fresh urine sample.
- Mix the urine to ensure homogeneity.
- Use a refractometer to measure the specific gravity.
- Record the result.
Specific gravity is a measure of the quantity of solutes per unit volume of a solution. In the context of urine, it helps in understanding the kidney's ability to concentrate urine and is indicative of various medical conditions. A refractometer is used to measure this property as it provides a quick and accurate reading. Specific gravity is traditionally easier to measure than osmolarity which is the number of osmoles per liter of fluid. A urine specific gravity higher than pure water indicates the presence of solutes.