Patent ID: 8139439

Claim:
A method of calibrating a seismic sensor, comprising: injecting a current into a moving coil of the seismic sensor; measuring a voltage across the moving coil; locking the coil such that environmental noise is reduced while measuring the moving coil voltage; and determining DC resistance (DCR) of the moving coil, wherein DCR of the moving coil is determined by: r = R E 02 - E 01 E c ⁢ ⁢ 2 - E c ⁢ ⁢ 1 - 1 , where r is the DCR of the moving coil; R is the series resistance; and E 01 and E 02 are supply voltage and E c1 and E c2 are moving coil voltage at different amounts of current, I 1 and I 2 , respectively.