Is there an accurate phone app altimeter ?

[DavidGraves]

Howdy

Can anyone recommend a pretty accurate cell phone app altimeter ?

I have a long gravity flow domestic water line and I need to do some regrading.....need elevation data along about 1/2 mile of pipeline.

Many thanks

David Graves

 

[Taku]

There are many free apps for both iPhone and Android. Might just load a few up and try them out to see what works best. Some require cell connection, some don't

 

[PaulT]

David,
Problem is not app related but GPS related. Altitude is not measured as accurately with civilian gear. Another option is barometric altimeter.

Beg, borrow or buy one. Perhaps, your local Airplane Owner & Pilots Association can provide one removed from an aircraft, or you could get one from REI.

A lot depends on what accuracy you need and over what time frame. Over a period with steady barometric pressure, you could do fine, but if a storm is approaching or leaving, the barometric pressure may change over a short time period that could make your readings less useful.

I would check with an avionics repair facility to see if they have something that would work for you.

For what you want to do, one cheap approach may be to use the pipe and add a transparent section of hose with measured markings.
Attach to pipe and hold vertically on the downhill end. Fill the pipe with water on the uphill side. The height of water in the downhill side is the same elevation as the top of the water in the uphill side. Read the height in the marked transparent tube to know the elevation difference,

Paul

 

[DavidGraves]

Thanks Paul

Half a mile or more of pipeline and wooded hilly terrain.

I have a transit but cannot make sightlines for trees and such.

I will look into a barometric app.

david

 

[Wandering Sagebrush]

David, I agree with Paul on the phone apps. GPS is all over the place.. You might be able to rent a barometric altimeter from an outdoor program or an outfitter. The better (?) multifunction watch style are in the $200+ range. I believe Brunton still offers an anemometer + altimeter. I would loan you my really old Brunton , but it gave up the ghost years ago after a nasty fall.

 

[PaulT]

david,

Use the pipe you are laying as the level tube unless it is one piece. If you have to join pieces, it should be possible to cobble something together to work. At the starting end, attach a short vertical piece to the pipe with a funnel into which to pour the water.

At the down hill end of the first section, make an adapter using something like a bicycle inner tube to atttach to the pipe with a hose clamp and also attach the vertical measuring tube.

Pour water into the funnel until it is full. Go to the downhill end and read the height on the transparent vertical tube. Now you know the delta in elevation. Remove the vertical tube and join the next section. Reattach the vertical transparent tube to the new downhill end.

Repeat the filling operation until done.

You are using the half mile pipe as the level.
Alternatively, use a 100 ft length of garden hose and do the work in 100 ft sections.

https://en.wikipedia.org/wiki/Water_level_%28device%29

I checked specs on a $200 barometric altimeter and it gave accuracy as within plus or minus 50 ft
This one says 3 ft resolution but that is not accuracy.

Anyway, good luck and full flowing water.
Paul

 

[ntsqd]

Suggest adding both a surfactant (soap could work but there are other options) to eliminate or reduce the meniscus, and some food coloring to the water.

 

[DavidGraves]

Thanks all for the wonderful suggestions.....I have been building homes and shop work for the last 58 years and I understand that water runs downhill.

My aim here is more simply to check the altitude of two fixed points, about 1/2 mile apart up a mountain creek....and at my home.

I hoped some of them new fangled smart phone thingys would make it simple.

The water line has existed since 1942.....I have been working on it since 1999.

It is sort of an Oregon Vortex thing with lots of ups and downs and a huge low swing below the road bridge and then back up to my domestic tanks at the house....grown men plumbers have sat and wept trying to get it all to work....one went mad and jumped in the creek.

David Graves

 

[rando]

Wouldn't it be easiest just to measure the pressure at the bottom end of the pipe?

If the inlet is a stream - just measure the pressure at the outlet with a faucet pressure gauge. The elevation change between the two ends of the pipe (in meters) is the pressure (in bar)/0.0981.

Otherwise your iPhone does have a barometric altimeter built in - but I am not sure a barometric altimeter will be any better than an augmented GPS:
https://apps.apple.com/us/app/barometer-altimeter-pro/id923043780

 

[pvstoy]

I would take the time and run a level moving it down the route. Each movement forward would back sight back two spots to confirm sighting then sight foward. Since putting this much effort would use lath to mark elevations and stations along the way. Good note keeping to do the math is a must. Not the quickest way but with patience and accuracy you can get a accurate profile of the run. Then it is a matter of cut and fill along the way.

If you have a hand held inclinometer can work in two person team and work your way down the slope noting elevation changes in short runs distances.

Half a mile worth best to use lath, flagging and a marker to write on the lath as soon you will forget the details to work on later.

Good luck... yea as we learned in school...water runs downhill

If you do have some uphill sections could consider some self venting stations along the way.

 

[DavidGraves]

Wouldn't it be easiest just to measure the pressure at the bottom end of the pipe?


Howdy Rando


Pressure ??? HA HA Ha Ha Ha Ha!!!!!!!!!!!!!!!!!!!!!! ...makes me want to jump in the creek.......we're talking gravity flow here...........I'm heading to the creek........pressure ????????

If the inlet is a stream - just measure the pressure at the outlet with a faucet pressure gauge. The elevation change between the two ends of the pipe (in meters) is the pressure (in bar)/0.0981.

Otherwise your iPhone does have a barometric altimeter built in - but I am not sure a barometric altimeter will be any better than an augmented GPS:
https://apps.apple.com/us/app/barometer-altimeter-pro/id923043780

 

[rando]

Gravity flow is exactly the answer!

Pressure = density * gravity * height. Density = 1, gravity = 9.81

You may need a more sensitive pressure gauge, but if you want to know your (net) head, you measure the pressure at the bottom. If you have no pressure you either have a leak or no head.

Something like this should give you a sensitivity to about 0.1M in height:
https://www.amazon.com/Winters-Economy-Pressure-Display-Accuracy/dp/B0087UBDAQ

 

[ckent323]

Interesting topic. Seems that if you need elevation accuracy to less than +/- about 20 feet then using a smart phone app is not the way to go. Some smart phones have barometric compensation built in and may be capable of reporting altitude within +/- 10 to 20 feet with appropriate application software.

https://www.singletracks.com/blog/gps/gps-elevation-accuracy-test-smartphone-apps-vs-dedicated-gps/


If you need accuracy to less than 10 - 20 feet then you will need a calibrated and barometric pressure as well as temperature compensated altimeter.

http://aviationknowledge.wikidot.com/aviation:sensitive-altimeters

 

[DavidGraves]

Many thanks to All....

This was fun hearing lots of good ideas....

But I need accuracy to within a foot.

I guess the short answer to my query is that there really is no accurate Smart Phone app for altitude.

Maybe we should have a party at my house to work on the pipeline !

Thanks Again.

David

 

[smlobx]

I believe my Garmin InReach can accurately measure elevation...maybe you could rent one at your local REI?

 

[DavidGraves]

Howdy

Thanks for that...what accuracy can you get with it.....change between to point visibly different...say three feet ?

David

 

[Arctic]

What did you wind up doing?

Water can also run uphill.
Ask a roofer.
Capillary action.

Use a level and level rod for elevation changes.
Ask a Surveyor.
Far more accurate than any other method that relies on barametric pressure or GPS and you really need gnats ass measurements for the differences you are calculating.

If you are keeping the same route for the waterline and doing grading, then the inlet pressure should not be effected and the outlet pressure (head pressure) should improve due to less pipe required with fewer ups & downs. Shorter pipe length means less pressure loss from friction inside the line.

Are you upgrading the line? Possibly increase diameter.

 

[PackRat]

David....given that you need to fork out some cash for gizmos you probably won't be using enough to justify their purchase, let me ask a couple simple questions.
1) as long as the source is higher than the end of your service, gravity should work out OK for you, right?
2) if you have enough differential between the source and end of service, gravity will overcome a few blips in altitude along the way, would it not?
3) if you prime the line to remove any air gaps where the blips in altitude are, you should get a decent flow if you have enough differential between source and end of service and if the diameter of the pipe is large enough
4) while the smart phone accuracy may not be enough, couldn't you get a decent altitude at the source and at the end of service using Google mapquest? Again, as long as you know there is a differential, that should work.
5) the problem may be that at some point the pipe comes so close to the altitude of the source that gravity isn't sufficient enough to supply you at the end use location.

If you ever tried to siphon gas into a gas can, you already know that the flow will increase the lower the end you are trying to fill a gas can with and conversely, once you have enough, as you raise the hose, the flow is reduced....until flow stops and air enters the hose as the remaining gas in the hose reverses direction back into the tank.

 

[ntsqd]

Is the distance involved too great to use a fluid filled clear tube? With both ends open to the atmosphere the fluid will be the same height at both ends. Measure to the ground from the fluid level to get the elevation difference.

 

[Optimistic Paranoid]

My aim here is more simply to check the altitude of two fixed points, about 1/2 mile apart up a mountain creek....and at my home.


David Graves

I know I'm coming to this late, but I'm scratching my head. If you just want to know the altitudes at two different points half a mile apart, why don't you just consult a USGS survey map? Or am I missing something?