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What is the generic name of the electronic hand-held device that measures the relative height of two different points (altitude, etc.)?

As an example, suppose I'm climbing a tree. I turn on the device, put it in my pocket, and once I've climbed 15 feet from the ground, the device should indicate "15 feet" on its display. When I climb further up to 20 feet, the device should indicate "20 feet" on its display.

I used to measure different levels using a Dumpy level and total station "distant measurer-laser." I need a different kind of device that can take levels more quickly but I don't know what this device is called or how to select a particular model. In addition to the name of the device, what properties of the device should I be looking at in order to take measurements more quickly?

hazzey
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Pretty_Girl
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MWijnand is correct that what you are looking for is an altimeter.

However, you will not find anything that could provide you with accuracy anywhere near the scale of a correctly used total station. From my experience you would be lucky to find something which would be able to find precision down to the 5' of elevation and accuracy with this device would take more time than setting up a total station.

To provide accurate differential altitude measurements you would need two of the same altimeters, both calibrated and showing exact altitude while placed beside each other. One would remain on the bottom of your measurement while the other would travel to the top. Once reaching the height you would like to measure they should remain still for 5-10 minutes to normalize followed by a reading. With my work we typically take 3 cycles of readings and average (or throw out a really bad reading).

The reason for needing two altimeters is because they measure altitude based on barimetric pressure. The pressure they are reading would change any time the weather also changes (wind changed direction to a degree would cause a flux in the pressure across the sensor).

Simplest solution

Continue to use the total station or carry a heavy plumb bob up the tree with you.

Community
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Dopeybob435
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GPS would be the best solution provided the desired measurement location has access to multiple satellites (not in a cave, steel building, deep canyon, etc).

Like Air mentioned, smartphones have built in GPS modules that will work well in many situations. This gps world article estimates consumer grade smartphone resolution to be 2 to 10 meter depending on signal quality.

Turn-key unit with 1cm accuracy: Ashtech ProMark 120
A good overview of diy modules: Sparkfun GPS Module Comparison
A $900 1cm resolution module: Piksi GPS receiver featured on Hackaday

ericnutsch
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Have you considered using a laser level device?

I've seen estate agents (realtors) use these for measuring the size of rooms. You could point one at the ground and it would give you your elevation.

The advantages are relative cheapness and reliability, the main disadvantage is it requires line-of-sight.

Jim Hargreaves
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