Seismic monitoring system with display (SW-74SI)

High-end model of SW-74 which can indicates SI (Spectrum Intensity) value.
Multi-functional equipment which can be set acceleration, seismic intensity and SI value individually.
Seismic monitoring system with display (SW-74SI)


  • ■ Indication function

    Importance level of information is shown by back color. It can be recognized even by remote watching. On earthquake ocurrence, “ocurrence time”, “peak acceleration”, “seismic intensity scale (measured seismic intensity)” are displayed.

    Indication function

  • ■ Memory function

    Memory function

    Up to 50 time histories can be saved.
    *Option software is needed to export waveform data.

  • ■ Alarm setting

    Alarm setting

    3-step alarm output by acceleration is possible. Alarm level is possible to be set.

  • ■ Correspond to SI value

    SI value which is correlated to typical damage on houses or buildings is getting popular at gas plants. SW-74 SI is the high end model having all fuctions of SW-74 plus SI value processing function.

    *SI value…“Velocity response spectrum” is one of the standards to express an earthquake destructive power given on structures. If the structure has high rigidity, the velocity natural period is between 1.5 – 2.5 seconds. The integrated value (area of the spectral distribution) can be one of the factors to represent the destructive power of earthquakes. Therefore, it is called as “spectral strength : SI Value”.

  • ■ Alarm setting

    Compact size makes easy installation. It can be stored in a rack.

  • ■ Easy to operate

    Easy to operate

    Touch panel is adopted. Easy operation makes speedy confirmation in an emergency.

  • ■ Waveform observation

    Waveform observation

    By connecting with PC on which the option software is installed, various settings of the device and seismic waveform data stored in the internal memory can be acquired.

  • ■ Power supply

    Select from AC 100 V or DC 24 V (Option)

System composition

System composition

Outward dimensions

Outward Drawing


Item Specification
Display element STN monochrome LCD with touch switch / back light color : green / orange / red
Earthquake monitor display Present time
Earthquake generation display Earthquake generation time, maximum acceleration, seismic intensity scale, alarm operation
Alarm hold display Avobe + reset button (whole reset of alarm / buzzer)
Setting display Trigger, alarm, date & time
Maintenance display Pickup test, earthquake history
Alarm and buzzer Upper limit 3-step (ALM1–3), individual setting, buzzer for point,
Alarm setting value : 0.1 to 999.9 (gal / seismic intensity scale / Kine)
Setting interval : 0.1 step,0.0 is alarm operation OFF (seismic intensity scale alarm is set byinstrumental seisimic intensity value)
Extra alarm Alarm step Upper limit 7-step (ALM4–10), individual setting (acceleration / seismic intensity scale / SI value/any setting is possible)
Alarm setting value 0.1 – 999.9 (gal/seismic intensity scale / Kine) setting interval 0.1 step,
0.0 is alarm operation OFF (seismic intensity scale alarm is set by instrumental seismic intensity value)
Alarm contact 1a contact (photo MOS relay) independent COM 2-point (ALM1–5, ALM 6–10, each 1-point)
Contact rating 200 V – 0.65 A (AC / DC, peak value)
Alarm and buzzer
reset method
a. Automatic reset by an internal timer 1 – 9999 sec. (setting interval 1 sec., 0 is automatic reset OFF)
b. External reset terminals (all steps reset by non-voltage [a] contact)
c. Reset button on the touch panel (effective on alarm display)
FAULT alarm (Power failure or system abnormal) 1a / 1b contact switching type
Contact rating : 2 A 30 VDC (maximum allowable voltage / current : 220 VDC / 2A)
Serial output For maintenance (conforms to RS232C ) : MC1 (switch over)
For external display (conforms to RS422) : MC2
For printer (conforms to RS232C): MC2
Back up unit Backup time > 10 min. (ready time), charging time < 48 hours
(no function at the operation by optional power 24 VDC )
Mounting method Wall hanging
Operational temperature
0 to + 50 °C
Operational humidity range 10 to 85 %RH (non-condensing)
Power supply AC100 V ±10 %, less than 50 VA DC24 V ±10 %, less than 70 W (option)
Mass Aprox. 3 kg


  • ■ External display (ED74)

    External display (ED74)

    Indicates acceleration amplitude, seismic intensity
    scale and alarm occurence time.

  • ■ Multiple control unit (2 out of 3) CU-5

    ■ Multiple control unit (2 out of 3) CU-5

    This device makes reliability of the relay contact output of
    the alarm signal to control or stop activation higher.
    An alarm signal is output when 2 units out of 3 generate
    alarm signals.