Which of the following is used to determine the total number of white blood cells in urine?

Chemical test strips are primarily used for qualitative analysis of various substances in urine, such as glucose, protein, and ketones. While they can indicate the presence of white blood cells indirectly through markers of infection, they do not provide a direct count of these cells, making them unsuitable for determining total white blood cell numbers.

A refractometer measures the concentration of solutes in urine by assessing the refractive index. While it provides useful information about urine concentration and hydration status, it does not evaluate cellular components like white blood cells and thus cannot be used to determine their total count.

A urinometer is an instrument designed to measure specific gravity or density of urine. Similar to a refractometer, it provides information about the urine's concentration but does not assess cellular content, including white blood cells, leaving it ineffective for this purpose.