The five-axis machine tool is of crucial importance in smart manufacturing. Its positioning accuracy is affected by the geometric error of the rotary table, which is the key component of the five-axis machine tool. 
Portable Continuous Angle Standards (POCAS) which the design concept is based on the encoder calibration technology is developed by Center for measurement standards, ITRI. The measurement error caused by manual installation can be eliminated by the special mechanism and algorithm. Therefore, the installation and measurement process can be completed within 30 minutes. POCAS is able to measure the positioning error (angle) and linear error simultaneously. Moreover, its positioning and linear uncertainty is less than 0.8" and 3 µm respectively.

The positioning error(angle) is the most important kind of  quality control for rotary table domestic manufacturers. Nowadays, the manufacturers use the laser interferometer to do this kind. This developing technique, a traceable angle standard, can directly be used in the production process. The setup and measurement of time can decrease within 30 minutes which is better than the normal measurement method.

The rotary table is a key component of the five-axis machine tool. Recently, domestic manufacturers develop to the multi-axis machine tool. In the factory manufacturing end, this technique provides a crucial angle standard.