Magnetic tape device comprising a characteristic magnetic head and a characteristic medium

A magnetic tape device comprising:

• a medium;
• and a magnetic head,
• wherein
• the medium is a magnetic tape,
• the magnetic head includes a module including an element array including a plurality of magnetic head elements between a pair of servo signal reading elements,
• the magnetic tape device changes an angle θ formed by an axis of the element array with respect to a width direction of the magnetic tape during running of the magnetic tape in the magnetic tape device,
• the magnetic tape includes a non-magnetic support, and a magnetic layer including a ferromagnetic powder,
• the magnetic layer includes a plurality of servo bands,
• in a case where a maximum value of an absolute value of a difference between a servo band spacing obtained before storage in an environment of a temperature of 32° C. and relative humidity of 55% and a servo band spacing obtained after storage in the environment for a storage time T is defined as A, a unit of A is μm, and T is set to 24 hours, 48 hours, 72 hours, 96 hours, or 120 hours, a medium life calculated by a linear function of A and a logarithm loge T of T, that are derived from a value of A and a value of the logarithm loge T of T obtained for each T is 5 years or longer,
• the medium life is the storage time T when A satisfies Equation 1:
• A=1.5 −B+C, (Equation 1)
• the B is a value calculated by multiplying a difference between a maximum value and a minimum value of servo band spacings obtained
• in each of the following five environments of
• a temperature of 16° C. and relative humidity of 20%,
• a temperature of 16° C. and relative humidity of 80%,
• a temperature of 26° C. and relative humidity of 80%,
• a temperature of 32° C. and relative humidity of 20%, and
• a temperature of 32° C. and relative humidity of 55%,
• by ½, and a unit is μm, and
• the C is a value calculated by
• C=L{COS(θinitial−Δθ)−cos(θinitial−Δθ)} and
• a unit is μm,
• the L is a distance between the pair of servo signal reading elements and a unit is μm, and
• in a case where the angle θ at start of the running of the magnetic tape is defined as θinitial,
• a maximum value of the angle θ during the running of the magnetic tape is defined as θmax, and a minimum value thereof is defined as θmin, and
• the Δθ is a greater value between values calculated by
• Δθmax=θmax−θinitial and
• Δθmin=θinitial−θmin.