In the specified factors, the ability of the instrument to maintain certain properties unchanged over time is called stability (degree). Instrument stability is the chemical industry group instrumentation workers are very concerned about this performance indicator. Because the chemical industry group consumes the instrument's environment difference is worse, the measured medium temperature, pressure change also difference is big, in this kind of environment puts in the instrument to consume, the instrument's certain parts with the time to keep the unchanging ability will be reduced, the instrument's stability will fall back. Favoritism or characterize the instrument stability now there is no quantitative value, chemical groups usually use the instrument zero drift to measure the stability of the instrument. Instrument put into operation for 1 year in the zero position do not see drift.
