altimeter for ground level, are phone apps any good

[ProDave]

If you need to pour concrete above ground level at the lower bits you will have to fit shuttering to contain the pour.

[markc]

55 minutes ago, LSB said:

we decided to try a water level, cheap and cheerful, first one arrived, only a plastic tube and no syringes to measure.

returned and another one ordered so going to try today.  We know it's not level so that will be a good start as it will be easy to get more accurate.

There is one patch that is quite a bit lower, we have plenty of spare soil to top up, but that will then need to be shored up for trench as it won't be solid enough.

 

First though is persuading the dumper / digger to start in negative temperature.

 

 

You don’t need syringes and no need or reason to measure the amount of fluid. You simply hold the tube in a U shape and add water to an inch or so from the top and it’s ready. 

[Canski]

10 minutes ago, markc said:

You don’t need syringes and no need or reason to measure the amount of fluid. You simply hold the tube in a U shape and add water to an inch or so from the top and it’s ready. 

Just be careful of air pockets in the tube. We used these a lot in Germany and they were very good for getting in and out of rooms. You can’t beat a decent laser though. 

[LSB]

we do have a laser, need to find it and set up and find the tripod or something to put it on.

 

 

[markc]

4 minutes ago, LSB said:

we do have a laser, need to find it and set up and find the tripod or something to put it on.

 

 

I use a laser all the time and never had a tripod for it. L shaped bracket screwed to wall or clamped to door or frame for high level line or stand laser on floor or on a block for low level stuff

[saveasteading]

OK, to pick up a few points.

1. A dumpy level was a trade name for a very simple optical machine on a tripod.

Basically a small spirit level with telescope. It had to be adjusted to level every time it was pointed. Now the equivalent (that shiny leica) does the levelling automatically. 

Just using a stick with a reference on it allows 'up a bit  down a bit' for a level surface.

But you can use a water level £25, for that.

Otherwise you use a staff with person holding it and a lot of sums, many negative.

About 1/4 of the population can do the sums with an optical level, after training.

 

2. The zip level uses atmospheric pressure to tell if a point is higher or lower than the base station.

Accurate to a few mm unless the sun hits it, when it needs zeroing. Great for house surveys as it goes through doors and up stairs. Also for single person operation. ( I could check levels after the workers had gone home.)

Nobody else in the company used it.

 

3. Google earth and most apps just apply a recorded altitude to a location. Very  approximate (+/- 1m) on a gently sloping plane, and much worse at steep slopes.

 

4. If a builder is having problems with a simple footing (it is horribly common) , change  builder urgently.

[SteamyTea]

15 hours ago, saveasteading said:

3. Google earth and most apps just apply a recorded altitude to a location. Very  approximate (+/- 1m) on a gently sloping plane, and much worse at steep slopes.

  

On 08/01/2023 at 21:37, SteamyTea said:

Interesting, I put my GPS logger on today, drove 600 miles, parked back in my drive and the altitude gap was 2' (600mm).

But this week I had an altitude gap of 8' (2440mm), as they were both minus numbers, that is a 6' (1830mm).

 

So I would conclude that GPS (on a phone) is not too good, or my house has sunk.