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Analysis: Best value logging altimeters

Discussion about deployment systems including altimeters, timers, air speed flaps, servo systems, and chemical reactions.
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anachronist
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Analysis: Best value logging altimeters

Postby anachronist » Wed May 24, 2017 9:41 pm

I imported the list at http://www.perfectflite.com/SLCF.html into Excel and set up some data filters to find a logging altimeter (NOT peak altimeter) with a PC interface for downloading flight data.

The best prices are the Eggtimer altimeters. The regular Eggtimer is $35 ($40 with USB cable) and the Eggtimer Quantum is also $40. The Quantum has really cool WiFi and data transfer features. The problem is, Eggtimers are kits. You have to invest in a 15-watt soldering iron and a lighted magnifier. You need steady hands to solder the tiny surface mount components. So your total cost will be more, maybe $65 plus the value of your time. If I were to go with Eggtimer, I'd definitely get the WiFi model - not only is it more convenient to download data, but it's configurable through any browser, and weighs 15g, less than the standard Eggtimer. But you still need to add the weight of a battery.

Then there's the Adrel ALT-BMP for around $63 according to that table, but nobody is selling it!. Their website refers you to another website that doesn't list the altimeter in their catalog. So we'll scratch that one.

Going a few dollars higher in price, the PerfectFlite StratoLoggerCF with USB data transfer kit is $72. It's about the same size as the Eggtimers but a bit lighter at 11g. Its launch detect is 160 feet though, so for the same price you can get the PerfectFlite Pnut, which has a launch detect as low as 40 feet and weighs only 7g including the battery.

Then there's the Altus Metrum MicroPeak. The advertised price is $30, but it really costs $80 because you have to invest in an optical USB transfer adapter to get data off the device. The advantage to this altimeter is that it weighs less than 2 grams with battery! Also for $80 is the Altus Metrum EasyMini, which is only 7g (but still needs an external battery) and has the USB connector built in, as far as I can tell.

One other consideration: The Pnut and MicroPeak are approved for pyro rocket competitions. The water rocket competitions don't require that, but it's good to know.

The above analysis sets a price range from $65 to $80 for a decent logging altimeter. If you're good at soldering and already have the soldering equipment, and you can tolerate the weight of an additional battery, I'd go with the Eggtimer Quantum. Communicating with the device over WiFi is a huge value for that price. If weight is a consideration and you don't want to solder, I think the Pnut is probably the best value in terms of price and weight, and also has the lowest launch detection height.

The next higher price point is around $100, where we have the MissileWords RRC3 Sport, Entacore ISM USB, and Jolly Logic Altimeter Three. If you're going to spend that much on a logging altimeter, I'd go with the Jolly Logic due to its LCD display -- but this altimeter doesn't have any parachute deployment features. All the other ones do.

So I'm leaning toward the Pnut even though the price is a bit steep for a device that I might lose in a tree!
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anachronist
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Re: Analysis: Best value logging altimeters

Postby anachronist » Tue Jun 06, 2017 3:40 pm

Looking further... if you need deployment capability, the Pnut and MicroPeak don't have it. In that case the EasyMini is probably the best option for weight, although if you can stand an idditional 10g, the WiFi capability and convenience of the EggTimer Quantum may well be worth the additional weight.

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