iPhone as level

[Janger]

Hi
I downloaded this Stanley iPhone level app. It’s interesting. I don’t have a machinist level yet so I’m trying this and wondering how it compares to a true level. The app seems to measure to one decimal point eg 0.0 degrees.

The app has an unique calibration function where you measure a surface one way then turn the phone 180 degrees and measure it again. It can then calibrate to zero. It seems to be “accurate” to about +/- 0.1 or so.

The buttons on the side of the phone do get in way.

Does anybody want to try a comparison of a machinist level to this app and explain how much more accurate a true level is? If you can figure out how many more decimal places the analog level can do it would be interesting.

 

[Bofobo]

Your i phone came with a level function, its hidden in the compass app. I use it from time to time, its pretty touchy, but seems accurate enough to keep a marble from rolling off a shelf. Always wondered how it would compare to a digital machinist level

 

[PeterT]

I put my Iphone against 2 el-cheapo digital levels I have & got similar results, within 0.5 deg if the surfaces were deemed consistent. BTW they often call them inclinometers on Ebay/Ali. I like the fact that most aftermarket ones are small & square so can position them or reference off another face & generally dirtier service than I want my phone in. Most have magnets which is handy but aluminum I just lightly clamp the body. I would get one with metal face vs. plastic. And thats kind of the issue with phone - how is it positioned in secondary tilt & how reliable is the edge, particularly with plastic or worse yet squishy protection case.

Example cheapo of which there are many
https://www.aliexpress.com/item/Dur...95cd7ce&transAbTest=ae803_1&priceBeautifyAB=0

Kind of an upscale with digital bubble
https://www.aliexpress.com/item/Hig...95cd7ce&transAbTest=ae803_1&priceBeautifyAB=0

 

[PeterT]

They can be handy for many applications. Most operate on a datum setting procedure so even if your work surface or mill table is at 1-deg, you can essentially make this a zero plane so all setup work is relative, This is different than 'plumb'. The typical zero datum setup is: Position one way click a button. Rotate 180-deg, click a button. Now it internally knows difference & computes this surface as zero degrees. Now every angle setup is relative to this. I've checked it against known angle plates & such. Hard to guess based on the actual unit, but I think accurate to within a degree. Repeat ability is another factor but as mentioned I think that may have more to do with the surface. Sometimes the outside case box is cheesy sheet metal or plastic, ie. maybe more ambiguous than the internal measuring accuracy. When I was setting up RC model stuff I used the magnet feature to clamp on a spare steel parallel & that became a more accurate straight edge combo. That worked great, but also was measuring non-magnetic things.

 

[JohnW]

My machinist's level will put the bubble off the scale when you place a sheet of regular paper under one end when it is on a level surface. That is about .003" in 6". I think it can reliably distinguish an out of level of better than .0005" in 6". Taking the arcsine of .0005/6 yields .005 degree. So it can distinguish better than 5 one-thousandths of a degree, or about 2 orders of magnitude better than one of the cheepie digital levels. It seems to be accurate in that if it is reading level, rotating it 180 degrees still reads level. It can only detect level, not an actual angle, which is a significant limitation.

I often use one the small digital levels to set an angle where I'm happy with a little better than 1 degree accuracy.

 

[Janger]

Thanks JohnW for doing the math and details that’s interesting. Post a picture of your level?. Kms has a Chinese level for $80 on sale now and then. I wonder if that is similar?

 

[JohnW]

That is effectively the same unit - it looks identical to mine. I bought mine a few years ago when House of Tools was being liquidated. 70% off or some such thing, I probably paid $40 or so for it. A bad deal so far, since I haven't really used it.

 

[Dabbler]

Janger, I have one if you need one. I don't need it any more.

 

[Janger]

Dabbler you have two? Selling one?

 

[Dabbler]

I bought a Moore and Wright last year, so my Chinese one is surplus. it is a 8 or 10" - I haven't taken it out in 3 or 4 years.

 

[Janger]

I’m interested John