We describe a computer-based data-acquisition system designed for the measurement of net water flux across epithelia. It is based on the detection of a liquid meniscus position in a capillary tube using an electro-optical device. Then the data are digitized, transferred to the computer main memory and saved in a file. The advantages of the system are: (a) to measure net water transfer with an accuracy of 50 nl; (b) to switch from absorptive to secretory conditions in real time; (c) data are directly digitized to be analytically, graphically and statistically treated; (d) the specially developed software allows change of time intervals for data acquirement and the scale in graphic events; (e) the software also allows recall to the monitor screen of graphics from previous tests or to print them on paper; (f) a simple mechanical structure, saving maintenance and time; and (g) high reliability.
Dorr, R. A., Kierbel, A., Vera, J., & Parisi, M. (1997). A new data-acquisition system for the measurement of the net water flux across epithelia. Computer Methods and Programs in Biomedicine, 53(1), 9–14. https://doi.org/10.1016/S0169-2607(96)01801-9