(Detail)
A seismometer placed around MCF is called RION seismometer. Its output is acceleration. Digital input filters are applied (by Shimoda-kun??) to convert it to displacement, and also to compensate the frequency response of the sensor. On the other hand, EX, EY, BS seismometers' outputs are in velocity. I noticed that the filters from MCF seismometer were applied to BS EX and EY, which is not right.
Today I changed the digital filters of seismometers at 2016/4/15 22:30 JST. The output unit has been changed.
for BS,EX,EY (Trillium Compact)
- output signals are in unit of velocity [m/s] ( output channels: K1:PEM-BS(/EX/EY)_SEIS_NS(/WE/Z)_SENSINF_OUTPUT )
- frequency band : 0.012-80Hz (+-1dB region)
for MCF (RION)
- output signal is in unit of acceleration [m/s^2] ( output channel: K1:PEM-MCF_SEIS_Y_SENSINF_OUTPUT )
- frequency band : 0.1-100Hz (+-1dB region)
The frequency dependence of seismometer's response is not corrected. So the filter is valid only for each frequency band (written above). If the correction is necessary, please see the manual. Attatched file is Trillium manual.
The source impedance of Trillium is 150[ohm], and the input impedance of digital system is 10k[ohm]? so the signal can become ~97% of original output. It should be calibrated if necessary.
