The SiSMoS-4 provides a PC-based, fast, four-channel, 24-bit data acquisition system with data-logger and spectrum analyzer for Bartington Instruments fluxgate sensors and industry standard ICP accelerometers. Applications include environmental monitoring (of EMI and vibration) for pre-installation surveys for MRI systems, electron microscopes and similar sensitive equipments. The SiSMoS-4 performs data acquisition in three channels for a triaxial sensor fluxgate or a one channel for a uniaxial accelerometers and produces both time domain and frequency domain plots showing either slow or fast trends for magnetic and vibration data in three axes.
The conversion of time-varying information into a frequency spectrum is accomplished using Fast Fourier Transforms referred to as FFT in the text. When used as a data-logger, time-stamped data can be logged (for extended periods) then retrieved and post-processed in both time and frequency domain. The system is software controlled and connection to the user’s PC is via a USB interface. Prior to data acquisition, system configuration is accomplished using the SiSMoS-4 software (Device configurationDevice configurationDevice configuration). Additional functions provided by the SiSMoS-4 system include:
- Selectable plot of time or frequency data
- Data post-processing (selectable filtering and averaging)
- Availability of cursors and markers for effective measurements
- Exports the graph data to excel file or to the clipboard in a tab-delimited format, which is accepted by most spreadsheet applications
- Saving of plots (images) in .bmp, .eps and .emf formats for use in reports
- Up to 10 hours operation powered by a rechargeable battery
- 51,2 kS/s sampling rate giving a spectral plot up to 25,6 kHz (-3dB point)
The SiSMoS-4 software records time and frequency domain data over a wide frequency range – from DC to 3.5kHz (-3dB point) for all input channels. Data logging with time-stamping is also provided hence the system functions as a high resolution data logger for magnetic and vibration measurements. The SiSMoS-4 software is compatible with Windows XP or later.
The SiSMoS-4 hardware unit contains a rechargeable battery for up to 10 hours operation under typical conditions to allow field-work with a laptop computer. In order to extend battery operation, magnetometer power is applied only when the user must use. The system is ideal for magnetic, vibration measurements and is also suited for recording the magnetic fields due to 50/60Hz mains supplies and associated harmonics.