The Potato test paper is designed to detect sugar levels in potatoes. The amount of free glucose is proportional to the darkness of the potato, thus the strip can be used to determine color prior to deep frying. Potato test paper can also be used to demonstrate osmosis across a membrane, similar to the way the small intestine works, by showing that glucose, but not starch, crosses the barrier. The color chart indicates concentration levels in mg/dL but this can be converted to mmol/L by multiplying by 0.055. eg. 100mg/dL is equal to 5.5mmol/L. Potato test paper is not intended for medical diagnosis. Should you decide to test your urine and you get any positive result you should report it to your physician and test your blood sugar levels.