Digital Protractor DXL360S GYRO + GRAVITY 2 in 1 Digital LCD Protractor Inclinometer Dual Level Shaft Box, 0.01° Resolution

These are absolutely fantastic. We use these to precisely level camera jibs to calibrate them for augmented reality graphics on television. With that usage, the difference between 0.00° and 0.02° is actually huge in terms of how things look on TV. A few important notes, it's extremely important to calibrate these devices every once in a while (or before each use if hundredths of a degree matter). This is a very simple procedure that takes 20 seconds from within the menu. Second, there is drift on these, meaning that, it will take a few seconds to dial into the final degree reading (in terms of the hundredths of a degree, it gets to within .05 degrees very quickly but will often drift to the final reading over about 5-10 seconds). The fact they work and rotate the display on all sides makes these invaluable. If precision is key, this is definitely a good buy.

++ the display refresh rate is fine, could be faster, but then your OCD kicks in ;) I wish the xy-axis measurement would also work when attaching vertically (upright on one of the four sides), but it only works if you have it flat on the ground on it's back. Once you tilt over a certain angle it switches to 1-axis only.++ The fake bubble display is helpful -- I didn't think it would be, but it is :) I also like that the display shows + and - degrees. I had another 1-axis one and that one would show, for example, "89°" for both left and right of 90°. This one shows very clearly the direction, nice.++ The device has an easy-to-navigate menu for calibration and alarm beeps, totally awesome, didn't see that in the description: you can enable a beep if the gauge is either *within* a certain degree or *outside* a certain degree, and also change the necessary accuracy. For example, if you set it to 24°, +-0.35°, INSIDE, then the gauge will beep between 23.65° and 24.35°. When setting to OUTSIDE, the beeping will stop inside this range. There are different settings for 1-axis, x-axis, y-axis! What is missing is enabling the beep ONLY for the x or ONLY for the y axis, in case you are aligning the scale to zero in one axis and are measuring the other axis' inclination.-- The display has a thin plastic layer and is a bit wobbly. I would suggest to leave the protective plastic layer that it ships with on it to protect it better from scratches.

The media could not be loaded. Seems to meet spec. If you put it on a nominally level surface, it flickers between -0.01, 0.00 and +0.01 degrees (the number does not read +/- but it shows a bubble position, left or right). If you put it on a controlled-tilt surface and change the tilt gradually, you can see the reading move gradually as expected, usually with +/- 1 count, occasionally a 2 count step but it's possible that is from some momentary seismic activity or passing cars. Remember 0.01 degrees is a very small angle, that is only 36 arc-seconds. I tilted gradually from +1 degree to -1 degree and back, and there was no hysteresis larger than 0.01 degree. Not every consumer widget claiming high resolution actually meets its spec, but I am impressed by this device.Minus one star because the advertised "USB serial port" on the DXL360S appears to require some nonstandard USB host software.EDIT: OK, turns out it's nonstandard hardware. The USB port works normally for charging its battery, but there is no USB data connection. However, the device generates a 3.3V 9600 baud serial UART signal (not USB) on the USB D- pin (that is the white wire, if you hack open a cable; black is ground, red is +5V). So if you're handy with electronics, you can make your own serial converter cable, making it into a real USB device. I did this and logged some data. It generates 10 readings per second but it's better to average quite a bit. I averaged 100 readings at a time (10 second intervals) and found that averaged reading was steady to +/- 0.02 degrees for many hours at a time, and also repeatable if you tilt away and tilt back, so my unit doesn't have much drift.

Easy to use. Matches other instruments, as much as I can test as this is much more precise. Also, readings are the same on different days so I assume accuracy is good.I bought this for setting up my telescope. First I level the mount using the digital bubble level feature. And then I realized I can set my declination whenever I change location by setting it on the top of my scope tube which is a nice added bonus for quick polar alignment.I also used it for flooring install, cabinet install, range hood install. Essentially, whenever I need to know if something is level, this tool comes out.Menu is a tad clunky but really not difficult to manage.Would buy again and recommend.

Unit will display a .3 degree difference for a given angle depending on which way the unit is oriented.Calibrating the unit does not remove the discrepancy. Does not come close to advertised accuracy, and.01 degree resolution of an inaccurate number is meaningless. I may have received a faulty unit, andwould return it if it was still within the return window.