In order to allow easy estimation of the operating condition of a magnet by
a technician of any skill level, and to allow accurate prediction of a
potential failure beforehand, a data processing section 52 is provided for
resolving pressure data for a cooling helium gas, level (remaining amount)
data for a liquid helium, first temperature data for a first stage of a
refrigerator, second temperature data for a second stage of the
refrigerator, and third temperature (room temperature) data for an
equipment room 13 in which a compressor 40 is placed, as prespecified
parameters, into a plurality of elements, using the elements as magnet
data, calculating the Mahalanobis distance D.sup.2 of the normalized
magnet data, and comparing the calculated Mahalanobis distance D.sup.2
with data stored in a database 53 obtained by developing magnet data in a
normal condition into a Mahalanobis reference space to estimate the
operating condition.
