Abstract: A test strip device exhibits visual changes, such as color changes, when there is a only slight difference in the composition of liquids such as gasoline, oil, ethanol and water. Such a slight liquid composition difference usually requires a sophisticated and expensive instrument to differentiate. The test strip consists of one and more than one inverse opal films deposited on a substrate and achieves this goal of differentiation in a simple, fast and energy-free manner.

Abstract: A helmet air conditioning unit configured for operation with a helmet having air flow spaces within an interior space thereof, the helmet air conditioning unit including an electrical ventilating fan with a housing portion having one or more exhaust ports positionable in fluid communication with the air flow spaces within the interior space of the helmet; a battery power supply connected to energize the fan; a solar power supply coupled to recharge the power battery supply; and a fan controller coupled for actuating the fan for generating a pressurized air flow at the one or more exhaust ports of the housing portion of the fan, whereby the pressurized air flow is directed through the one or more exhaust ports of the housing portion of the fan when the fan is actuated.

Abstract: A method and apparatus for relieving thermal stress on the flexures of an accelerometer, particularly a quartz accelerometer, caused by the difference in the coefficient of expansion of a bonding adhesive or a sealant placed over a bonding pad to protect or attach the ends of the torque coil and the coefficient of expansion of the quartz. The strain is relieved by supporting the bonding pads on flexible attachments to prevent thermal stress from being transferred into the pendulum and flexures.

Abstract: An improved accelerometer of the type that comprises a paddle (30), a support (32), and suspension means (34) for suspending the paddle from the support, such that the paddle can move along a sensing axis. The support includes an unclamped portion (42) to which the suspension means is attached, and a clamped portion (40) through which the support is mounted. The invention provides restraining means (72, 100, 120, 132, 134, 176, 196, 206) separate from the clamped portion of the support, for limiting the travel of the unclamped portion in directions normal to the sensing axis, for example, along the hinge axis. The result is an accelerometer able to withstand higher cross axis shocks without failure.

Abstract: An improved preload system for an accelerometer in which an acceleration sensitive structure is clamped between first and second clamping members. The acceleration sensitive structure includes a paddle supported such that the paddle has a degree of freedom along a sensing axis. The accelerometer further includes a case within which the acceleration sensitive structure and clamping members are mounted. The preload system comprises an internal mounting surface in the case that faces in a first direction along the sensing axis, and that contacts the second clamping member and prevents it from moving in a second direction opposite to the first direction. The preload system also includes a spring washer extending between the first clamping member and the case, such that the spring washer exerts a force on the first clamping member in the second direction. A positioning ring may also be provided between the first clamping member and spring washer, to laterally locate the first clamping member within the case.