Analog (traditional) goniometers are little more than an angle conveyor with a ruler attached at its center that can rotate freely from the joint. The main part of the tool is put on one of the points to be measured, and the ruler placed on the other. The angle can then be measured using the central circle or semi-circle.
Digital goniometers do not have complicated dial readings, as they display the information simply on an LCD screen. In addition, many digital goniometers offer other advantages, such as angle conversion. Here are some of the key advantages of digital goniometers:
They display the information on an LCD screen.
They have a backlight, so you can work in low light.
They let you convert angles to the sexagesimal system ( which is the most common), as well as to centesimals or radiants.
They let you store measurements and upload them to a smartphone or a computer.
Are faster, since you just have to place it on the surface you want to measure.
Some goniometer models let you combine them with other tools such as a laser level or a laser meter.