Abstract: A method and system for limiting energy to a sensor and/or an environment in which the sensor is located. A high current sensor driver is powered through a resistance-capacitance (RC) circuit. In a failure mode, the RC circuit constrains output of a sensor driver to the sensor in order to limit average current applied to the sensor. In one embodiment, the capacitor is chosen so that it can provide adequate current to the sensor driver for a short period of time. The value of the resistor may be chosen to ensure that under short circuit conditions direct current (DC) is limited to a safe value. The combined values of the resistor and capacitor may be adjusted such that the capacitor can charge to a prescribed level during the interval between active pulses.

Abstract: An in-line fuel properties measurement unit (IFPMU) (50) for in-line assembly in a fluid flow path, in particular a fuel flow path of an aircraft, includes a compensator section (58) and a densitometer section (60). The densitometer section is connected in-line with the compensator section such that full fluid flow is seen by each section. The IFPMU further includes a circuit card having tabs or “arms” for electrically interfacing with cylinders of the compensator section, wherein the cylinders include reliefs formed therein to create an air gap between the cylinder and the tab.

Abstract: An in-line fuel properties measurement unit (IFPMU) (50) for in-line assembly in a fluid flow path, in particular a fuel flow path of an aircraft, includes a compensator section (58) and a densitometer section (60). The densitometer section is connected in-line with the compensator section such that full fluid flow is seen by each section. The IFPMU further includes a circuit card having tabs or “arms” for electrically interfacing with cylinders of the compensator section, wherein the cylinders include reliefs formed therein to create an air gap between the cylinder and the tab.

Abstract: A method and system for limiting energy to a sensor and/or an environment in which the sensor is located. A high current sensor driver is powered through a resistance-capacitance (RC) circuit. In a failure mode, the RC circuit constrains output of a sensor driver to the sensor in order to limit average current applied to the sensor. In one embodiment, the capacitor is chosen so that it can provide adequate current to the sensor driver for a short period of time. The value of the resistor may be chosen to ensure that under short circuit conditions direct current (DC) is limited to a safe value. The combined values of the resistor and capacitor may be adjusted such that the capacitor can charge to a prescribed level during the interval between active pulses.