Brief:
The PerfectFlight Mini ALT/WD is a peak reporting and recording dual deployment barometric altimeter. It measures 3.0" L x 0.9"W x 0.7"H, and weighs 0.7 oz without the required 9V alkaline battery.

Construction:
Main deployment is selectable with deployment from 300' to 1,700' in 200' increments. The peak altitude on this model is 25,000 feet MSL.

The altimeter reports peak altitude after each flight. The beeper also provides an e-match continuity check when it's first turned on.

Once the flight is over, it stores over 5 minutes of flight data for later download to a computer. This data is stored in nonvolatile memory and is preserved even if power is lost. A small computer program and download cable is offered with it so the entire flight can bee seen on your computer. I use this feature extensively by downloading the data onto my lap top after each flight.

Mach delay is adjustable from 0 to 14 seconds for those neck snapping flights.

The power supply is supplemented by a capacitor. This allows it to lose battery contact for up to two seconds without loss of operation in flight.

Although I have never used this feature, it has an In-flight telemetry output for real-time data. This would have to be done with an RF link device that you would provide.

There is not a battery mount on the board like some altimeters. I like this feature because it allows me to use whatever battery I want and put it wherever I want. I usually use a standard 9v battery, but I have used a stack of watch batteries in a 38mm diameter bowling ball rocket. For arming and disarming [for every altimeter I use], I use the push on / push off switches that PerfectFlight sells. I like to mount all my altimeters with plastic PC board stand-offs and stainless steel screws, onto a ¼" aircraft plywood board.

Flight:
I have flown these altimeters more times than I can count, without ever having one fail. This may be due to the large on-board capacitor. Battery and switch contacts can be momentarily disconnected during the boost phase, or if the rocket gets knocked around during ejection or descent. Although I only use altimeters in big rockets, its small size allows it to fit in 38mm airframes.

Overall Rating: 5 out of 5

Other:
This is a fairly easy altimeter to use. I think the two best features are the capacitor for keeping it powered up and the download capabilities and software that comes with it. The software even allows you to adjust some setting such as the low battery alarm level