For digital measurement demands of the structure and equipment installation in the internal and external regional space

the associate technology of inside and outside reference points is researched. The internal measurement accuracy field united with the external measurement accuracy field is constructed. With regard to different openings between inside and outside spaces

utilizing the multi-spotting method

two measurement points and a level single-station positioning method

two measuring points and a level two-station positioning method

internal precision field is established to achieve the unity with external precision field. In a certain type of equipment

for example

experiment results show that the inconsistent measurement error of the same checkpoint between inside and outside measurement accuracy fields is up to 0.14 mm

which proves that the build mode is feasible

simple and reliable.