Abstract: A method and apparatus for measuring the density or specific gravity of a fluid sample uses a single sensor. A reservoir contains another fluid of known density which is not miscible with the fluid sample. Sensors are disposed proximate to the reservoir to detect the passage of the fluid sample through the non-miscible fluid medium. A microprocessor monitors the sensor and calculates the specific gravity of the fluid sample. The microprocessor measures the amount of time one sensor is eclipsed as the fluid sample droplet falls through the fluid medium and calculates the density or specific gravity based on that amount of time. The microprocessor also may measure a second amount of time, the time required for the fluid sample to traverse through the fluid medium between two sensors. The microprocessor can use this second amount of time to measure the fluid droplet diameter or size. The microprocessor corrects the calculated density or specific gravity for any deviation caused by the size of the fluid sample.

Abstract: The removal of excess fluid from a test strip should be performed in a consistent manner to provide consistent results. To eliminate user variability introduced by manual blotting techniques, the device of the present invention wipes fluid from a test strip as the test strip is passed beneath a blade. The one-piece device is made of plastic so that it may be manufactured inexpensively and disposed of after use. The wiping device can also be integrated with an end cap, so that the wiping device can be attached to the end of an instrument, such as a lancet. To obtain a blood sample, for instance, the user inserts a test strip into the wiping device, where it is held while the blood sample is taken. The user deposits the blood sample onto the test strip and pulls the test strip through the wiping device. The blade removes a portion of the blood sample to provide a consistent wiping action which is not influenced by user variability.