Final answer:
The policy states that the difference between the dialysis machine conductivity reading and the manual reading should be equal to or less than 1.0 mS/cm.
Step-by-step explanation:
The policy states that the difference between the dialysis machine conductivity reading and the manual reading should be equal to or less than 1.0 mS/cm. Conductivity is a measure of the ability of a solution to conduct electrical current, which depends on the concentration of ions in the solution. When the concentration of ions is halved, the conductivity reading is reduced to half as well. Therefore, the conductivity reading is directly related to the concentration of ions in the solution.