After the flight, the AltimeterThree sends the flight data directly to your smartphone (YOU NEED A SMART PHONE TO USE THIS PRODUCT!). You don't look on the display to see the flight information, you look on your smartphone (either iPhone or Android). Once you have downloaded the data on your smartphone, you can view an interactive graph of altitude (and for certain sports, 3-axis acceleration) and produce a Microsoft Excel™ spreadsheet of flight data for further analysis.

Very easy to use: just install the AltimeterThree and power it on. Start the recording by pressing a button on your smartphone/tablet. After the flight AltimeterThree will automatically send the flight data via Bluetooth to your mobile device, where you can read them in detail or send them to you desktop computer for further analysis. 

If GPS is enabled on your phone, the location of each flight is saved, and can be viewed on a map. Integration with Facebook, Instagram, Twitter, and Flickr allow you to share your flights with just a tap.
AltimeterThree can be recharged from any USB port or charger (recharging cable included).

Product Specs:

• Weight: 10.6g
• Height: 14.5mm
• Width: 18 mm - Note: No longer fits inside 18mm tubes.
• Length: 49 mm
• Requires a smart phone for data capture (not included)

Features:

• Accurate 19-bit barometric pressure sensor sensitive to altitude changes of less than one foot (0,3 m).
• 3-axis, 24g accelerometer: used to detect launch, acceleration, speed, and ejection. No need to orient the altimeter into the rocket.
• It fits easily inside a BT-50 (24mm diameter) body tube.
• Rugged plastic case. You can mount it anywhere in the rocket, even in the body tube. Just protect it from the heat of the ejection charge. You can also put it in a payload tube, or on a specially designed altimeter mount.
• Daylight-readable LCD display.
• Rechargeable Lithium-Polymer battery lasts for hundreds of launches, no batteries to buy.
• Recharges in less than 2 hours from any standard USB port (charging cable included).
• Samples the atmospheric pressure over 30 times/second, and acceleration at 250 times/second.
• Stores information on flash memory - You can turn it off and then turn it back on to see data of the last flight. Note: It only stores one flight, not multiple flights.
• Automatically powers down to conserve power.
• Easy to tether to any part of the rocket. You don't need to mount it in an electronic bay.
• USB Current: approx. 90ma

User's Guide - Download the User Manual PDF format, 568K. Pages are in "print order," so that if you print 2-sided on regular sized paper and then fold and staple they make a book.

Made for iPhone 6, iPhone 6 Plus, iPhone 5s, iPhone 5c, iPhone 5, iPhone 4S, iPhone 4, iPad Air 2, iPad mini 3, iPad with Retina display, iPad Air, iPad mini 2, iPad (4th generation), iPad mini, iPad (3rd generation), iPad 2.

Works with most devices that run Android 4.0.4 and higher. Please download free app to test your compatibility before buying.

Ranges:

• Altitude to 29,500 ft (9000 m) above sea level.
• Capable of supersonic speed measurements.
• Maximum acceleration is from 23G (any orientation) up to 40g (with careful orientation).

Display Precision

• Altitude: nearest foot or nearest meter.
• Speed: nearest 1 MPH (1 Km/h)
• Acceleration: nearest 0.1G

Sensor Precision:
Pressure sampled 25 times/second using 18 bits of precision. Acceleration sampled simultaneously in all three directions at 250 times/second using 15 bits of precision each. Data is NOT downloadable.

Temperature Compensated: 16-bits temperature sensor to compensate for thermal effects in the pressure sensor across its temperature range (- 25°C to 49°C) and to compensate the atmospheric model used to convert true pressure to altitude.