LM1830N fluid detection IC by National Semiconductor. Package: 14-DIP Download National Semiconductor LM1830 datasheet: OK folk, looks like this is one of those rare and very expensive chips, where supply and demand dictates the price, but hold on now, lets not get carried away with silly ebay prices ( £117.89 / £59.05 / £53.75 ....3/9/2014), let do it at half the lowest price.... Why? because we can ! Status: NOS (New Old Stock) RoHS compliant: no simple circuit can be viewed here: www.circuitstoday.com/liquid-level-indicator