Abstract: A self-contained portable spirometer includes a housing and an air tube with an orifice. Within the housing there is a transducer and microprocessor-based circuitry for generating standard exhaled air performance measurements such as forced expiration volume and peak expiratory flow rate, commonly referred to as FEV.sub.1 and PFER. These measurements are displayed on a screen disposed on the housing. Since the air tube has a non-linear response, two amplifier stages with different amplification are coupled between the transducer and the microprocessor. The microprocessor monitors the flow rate through the tube and selects the signal from either one or the other amplification stage depending on the flow through the tube. The microprocessor also monitors the flow to determine when no air is blown through the tube. In this latter case, the computer shuts the power to the analog circuitry to conserve power.

Abstract: A dipstick locator device is mounted inside the engine compartment of a motor vehicle, and more particularly to the dipstick assembly. The device includes a light source which is activated at least when the hood is lifted to enable a person to locate the dipstick even under poor lighting conditions.

Abstract: A brake light enhancer circuit which may be readily connected to the brake light circuit of a conventional motor vehicle causes the brake lamps to be flashed a predetermined number of times when the brake pedal is initially depressed and thereafter causes the brake lights to be steadily illuminated so long as the brake pedal remains depressed. If, however, a turn signal indicator has been activated before or during the application of the brake pedal, the brake light enhancer circuit does not flash the rear brake lamps, but rather illuminates them continuously as long as the brake pedal is depressed. The circuit is configured so that normal brake light operation will not be impaired upon misconnection to the vehicle or failure or any component of the brake light enhancer circuit itself.