The entrance of water into fluid power or lubrication systems reduces the life of oil significantly and causes damage to other components used in the systems. The most reliable method of detecting water in oil is to measure the interface level between water and oil when the water is separated. The BÜHLER water alarm units have a float that rises in water but sinks in oil. It only takes a build-up of around 90 ml of water in the sight glass to elevate the float and actuate a contact to signal danger. Water alarm units for in-tank installation as well as with two switching points and higher maximum pressure are available upon request.