iPhone Spirit Level review
- Using the iPhone as a spirit level
- Is the iPhone 5s accelerometer reliable
- Would we use the iPhone 5s as a bubble level.
One of the neater features in iOS 7 was the introduction of a new spirit level feature, which is neatly tucked away inside the compass app. This can be used as a replacement for a bubble spirit level when putting up shelves.
The iOS spirit level app plays nicely into the iPhone 5s and Apple’s focus on the M7 motion co-processor, but is also available on all iPhone devices running iOS 7. It actually uses the accelerometer which has been present from the very first iPhone.
Why has the iPhone got a spirit level in it?
Why Apple has introduced a spirit level into iOS 7 at this point is something of a mystery. There have been several other spirit level style apps on the iPhone, all of which are generally seen as usable at a push but not exactly inspiring in confidence.
Apple introduces the compass app along with the iPhone 3Gs and its 3D compass feature. For most people the compass serves as little more than a novelty but it can be reliably used for navigation.
“As much use a box of chocolate frogs” noted one Macworld commenter, wryly when Apple introduced the digital compass to the iPhone. This certainly didn’t turn out to be true in the long run, after all the Directions component of Apple maps and several stunning augmented reality apps have put the compass to the test.
Using the spirit level app on the iPhone couldn’t be easier. Simply open the Compass app on the iPhone (it’s now available on the iPad).
Go to Compass, perform the calibration (rock the iPhone around in your hand) until the compass app appears. Now slide to the right to reveal the new Spirit Level.
Place the iPhone down on its side (either horizontal or vertical) and you’ll see a black and white horizontal section. in the middle of the screen is a number of the angle. Note that you can also took the iPhone back and forth to gauge the angle in all directions.
You can also lay the iPhone flat on a surface, in which case the spirit level turns into two circles that you can line up to get a flat surface.
When you have the iPhone at 0 degrees the line will turn green indicating that it’s all balanced.
At any time you can tap the screen to adjust the default balance, and then carry on making measurements. Tapping the screen again resents the default 0 degree level to horizontal.
How reliable is the iPhone bubble level?
The spirit level app itself seems perfectly usable to us. We tested it on a variety of different surfaces on an iPhone 5, iPhone 5s and against a regular bubble spirit level. All delivered pretty much the same report in each area (if anything the iPhone 5s seemed a little more accurate to us than the traditional bubble level).
Several reports have noted unreliability, however, and we have noticed that the iPhone 5s has been a bit out at times. Although a quick flick of the phone reset everything. It is possible that the iPhone 5s has a new accelerometer that is causing some issues:
Website GigaOm says “the iPhone 5s uses a Bosch Sensortec accelerometer, as opposed to the STMicroelectronics accelerometer used in previous iPhones.
Reality Cap CEO Eagle Jones says “the typical bias for the ST part is +/- 20mg, while the Bosch part lists +/-95mg. This almost 5x greater offset range is confirmed by our measurements”.
“Apple could potentially fix this issue by manually adjusting the bias in the manufacturing process“ says GigaOm’s Alex Colon.
Some pundits have tried to turn this into an ‘antennagate’ style ‘spiritgate’ perhaps being a tad optimistic about the general public's enthusiasm for taking horizontal measurements. Outside of the Spirit Level app the key use for the accelerometer is in games that use motion control. It would seem that the greater offense range of the iPhone 5s is barely noticeable when playing games.
We probably wouldn’t use either an iPhone 5s or an iPhone 5 as a spirit level Apart from not wanting our £550 phone around in a construction area we’d simply rather use a tool designed for the job. And the iPhone was never truly as accurate as a good bubble spirit level, in part because the shorter footprint makes it more susceptible to making an incorrect measurement.