Abstract: A liquid level sensor comprising a thermistor probe and a power source connected to the thermistor probe to heat the thermistor probe. A cover encases the thermistor probe and includes openings allowing liquid to enter and exit an interior of the cover and contact the thermistor probe. A detector detects a liquid level in response to a voltage at the thermistor probe.

Abstract: A cooling system is provided employing multiple coolant conditioning units (CCUs). Each CCU, which is coupled to a different, associated electronics rack of multiple electronics racks to be cooled, includes a heat exchanger, a first cooling loop with a control valve, and a second cooling loop. The first cooling loop receives chilled facility coolant from a source and passes at least a portion thereof via the control valve through the heat exchanger. The second cooling loop provides cooled system coolant to the associated electronics rack, and expels heat in the heat exchanger from the electronics rack to the chilled facility coolant in the first cooling loop. The control valve allows regulation of the facility coolant flow through the heat exchanger, thereby allowing independent control of temperature of the system coolant in the second cooling loop. Various CCU and associated component redundancies of the cooling system are also provided.

Abstract: Method, system and program product are provided for monitoring coolant within a cooling system designed to provide system coolant to one or more electronics subsystems. The monitoring technique includes employing at least one pressure transducer to obtain multiple pressure measurements related to an amount of coolant within an expansion tank of the cooling system, and determining a rate of volume change of coolant within the expansion tank employing the multiple pressure measurements. Successive pressure measurements can be taken at a known time interval to determine the rate of volume change of coolant within the expansion tank. An automatic determination can also be made on the immediacy of action to be taken for service of the cooling system based on the rate of volume change of coolant within the expansion tank.