VSI-1000 vertical speed indicator - $225

The Industrologic VSI-1000 Vertical Speed Indicator/Voltage Output Altimeter is a ruggedized instrument designed for parachute air drop testing and other applications where vertical speed at low altitudes needs to be determined by use of a voltage output into a data logger.

Based on a Motorola MPX4115A on-chip signal conditioned, temperature compensated and calibrated, piezoresistive absolute pressure transducer, it can be powered with anywhere from 8 to 18 volts DC regulated or unregulated at 13 mA, and has a voltage output from 0.5 to 4.5 volts for easy interfacing to 0-5 volt analog inputs.

The circuitry in the VSI-1000 has been designed to change the pressure transducer's scale and span to 0 to 1000 feet AGL readings, and has an adjustable offset to allow use up to 6000 feet field elevation. This scale and span allows quick and easy vertical speed determination by using time versus altitude change calculations.

The VSI-1000 is enclosed in a rugged die cast aluminum enclosure approximately 4.5" by 2.5" by 1.25", and comes with a pre-wired shielded cable connected to screw terminal blocks which can be easily changed by the user if desired.

http://www.industrologic.com