IESE

Because geophones are passive sensors, nominal responses assume that the sensor is level, the coil and shunt resistances match those listed for the response, and that the preamplifier impedance of the datalogger is at least 2 orders of magnitude greater than the sensor impedance match those listed. To learn how customize these nominal responses for your specific instrumentation, here. IESE does not list current damping or shunt resistor information, so responses are given with a calculated shunt resistance that assumes a total damping of 0.7071 critical. Additional parameters needed to customize these responses using the link above are as follows: | Fundamental Frequency | Mass | Open Circuit Dampiong | Intrinsic Sensitivity | | --- | --- | --- | --- | | 4.5 Hz | 0.023 Kg | 0.27 | 78.74 V/M/S | | 2.0 Hz | 0.023 Kg | 0.61 | 78.7 V/M/S |

G88

This geophone measures ground velocity. It has the same nominal response as the S21g and S31f with the same resistors.

S21g

This geophone measures ground velocity. It has the same nominal response as the G88 and S31f with the same resistors.

S31f

This geophone measures ground velocity. It has the same nominal response as the G88 and S21g with the same resistors.