Ideal Observation Precision of the LLMC

Basic requirements to reach the ideal observation precision are introduced in this paper.The method used for the error measurement is compared in this instrument with those of in traditional meridian circles,and new instrumental errors of the LLMC are found out.In order to determine the precision of all kinds of errors under the condition that the instrument is stable,the ideal observation precision of the instrument is estimated.It is pointed out that the precision of a single determination for each celestial body should be less than ±0.10″.Finally the reasons for not reaching to the ideal precision are analyzed.