The MC90-110 sensor provides a wideband response from Extremely Low Frequency (ELF) through Very Low Frequency (VLF) bands, with a wide rounded maximum near 1.8 kHz with response about 28mV output per mG field.  

Compared with the other sensors, Models MC90R and MC90-110 can be more easily damaged by suddenly turning on or off a strong field, or by a fast rise or fall time, or other sharp discontinuities in a strong field like sudden frequency or phase changes. These may produce a transient voltage spike in the large coil and output of these B-dot sensors, which could damage the sensor. If unsure, better to gradually ramp-up and down the field strength.