When comparing the accuracy data on the SulfaVer method, why is the standard deviation so much higher than other methods?
Standard deviation much higher than other methods
Because this method involves precipitation of sulfate with barium chloride, you are measuring turbidity rather than color. A lot of factors can affect the amount of turbidity formed, so there is a lot of scatter in the results. Hach recommends customers do their own lot-specific calibrations to minimize the lot-to-lot effects, but there can still be significant variation.