Precision Altimeter ?
Hello, Hope you are all healthy! We are still good thankfully. I was wondering if anyone has done this type of measurement in the setting described and if so could you please discuss it? Below is what was sent from the engineer, the names have been changed to protect the innocent.
“In reference to the discussion yesterday during the kickoff meeting for topography, structural made an inquiry of the building corners and interior. Civil will be picking up the building footprint, but nothing interior to that point. General model will be developed surrounding the building footprint. Structural would like a spot check of foundation conditions to see if deteriorated.
Does A or B have a High Precision Altimeter for performing interior differential elevation surveying? Based on the inquiry, we need to make sure we have something in place to best assess the existing foundation to determine if failure is occurring for the building foundation, or its just the sidewalks surrounding the building that are sinking”.
As always your thoughts would be appreciated.
Thank You,
Paul
- 6 Replies
ZIPLEVEL PRO-2000 High Precision Altimeter https://www.amazon.com/dp/B000N4WYJS/ref=cm_sw_r_cp_api_glc_fabc_UmCcGb6M1M282
interesting
does this work when the cable is in direct sunlight and when it becomes cloudy?
I have the same gear from Nivcomp but it only works precisely indoors.
A High Precision Altimeter won’t do the job. “It should be possible to determine elevations of field stations with an average error of less than 2 feet if the following conditions are met: [ . . . ]”. I’ve only used a pair when working for the Forest Service (can’t remember what we were up to except it involved a lot of steep trail hiking).
Clearly GPS for your task is a no go given that you’ll be partially working inside a building and they’re probably looking for an accuracy of less than 0.1′. Differential levelling is probably the best approach and you wouldn’t need a high order level to accomplish it.
ZIPLEVEL PRO-2000 High Precision Altimeter
Wow, never heard of such a thing, probably because it’s targeting the construction industry. It’s essentially a glorified water level with key improvements, one would assume a temperature insensitive fluid and tube, a sealed tube to eliminate interior bubble problems, and a mysterious super sensitive pressure sensor. Some thoughts:
- “Our new dual range ZIPLEVEL can now detect the thickness of a sheet of paper with 0.005? (0.1 mm) internal precision for measurements never before possible.” Really? The pressure differential of 0.1mm of a fluid with a density near water is about 0.00142psi; that’s one helluva accurate tire gauge. I’m skeptical.
- Since the horizontal range is about 100′ atmospheric pressure gradients are not salient; I’ll buy that.
- The owner’s manual states beware of sunny/shady differentials and windy conditions outdoors. A scenario where the base is outdoors and the remote is indoors subject to HVAC pressure differentials is a cause for concern.
Overall, it looks to be a wonderful instrument for your task, and at $900 maybe should be in every construction surveyor’s quiver. They’ve been in business since 2001 and have street cred. Here’s an eyebrow raiser; you can actually measure mountain heights using a leapfrogging technique (“at 2mph using a two person crew”) like traditional differential levelling:
Anybody want to comment on that?
It might be good I don’t know, but I will never believe it can measure the thickness of a sheet of paper. Since I find that claim incredulous, I do not trust their product.
meh….seems like a headache….
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