LEMI-025

Product type:
Fluxgate Magnetometer

Product description:
High resolution and precision
Low time shift of the acquired data
Low temperature offset
Convenience of installation and service
Automatic operation control
2 GB removable Flash card
Satellite synchronization
RS – 232 output
IAGA2002 formatted 1-sec and 1-min data
Deep suppression of the power mains interference
3 years operational guarantee

Application description:
Fluxgate magnetometer (FGM) LEMI-025 was developed for the super-sensitive measurements of 3 components of Earth magnetic field induction and their variations per new 1-second INTERMAGNET standard. The signals with periods from 1 to 100.000 seconds and more may be collected with reasonable error. In order to realize this design, major attention was paid to such principal FGM characteristics and parameters as frequency response and sampling synchronization accuracy as well as thermal and temporal stability and noise level. To fulfill such mutually contradictory requirements as the speed of response and the deep suppression of industrial noise, the specific combination of analog and digital filters was realized in this instrument. The magnetic sensor of flux-gate type, which mainly determines magnetometer stability and noise level, was manufactured with high-tech glass ceramics having close to zero thermal expansion factor using well-proven technology, which implements recent findings in the excitation circuit construction and operation mode. Three types of sensor construction are possible (optional selection, see Figures). Using the best available voltage references and passive components provides excellent stability of the FGM electronics.

This FGM is intended for operation in the geomagnetic observatory conditions and in normal operation mode requires an external PC for storing the acquired data. For this purpose, FGM includes RS-232 digital interface. It is also possible to accumulate data into an embedded removable Compact FLASH memory card up to 2 GB volume. This mode of operation is recommended as a temporary one only. The instrument has a GPS receiver for data sampling synchronization and FGM location coordinates determination.

Highlights:
Low noise level

Product image:

Specifications:

• Measured range of magnetic field variations | (±3000 nT)
• Offset compensation band along each component | (±65 000 nT)
• Resolution along each component:at the display | (0.1nT)
• Resolution along each component:in the 1-second and 1-minute data files | (0.01nT)
• Resolution along each component:in the 0.1-second and Flash card data | (0.001nT)
• Noise level in (0.01 – 1) Hz frequency band | (< 10 pT rms)
• Temperature drift | (<0.2 nT/°C)
• Components orthogonality error | (< 30 min of arc)
• Sample rate:at the magnetometer digital output and FLASH card : (10 per second)
• Sample rate: after PC software digital filtration | (1 per second,1 per minute)
• Frequency band for 10 per second data output | (DC – 3.5 Hz)
• Operating temperature range | (-5 to +40° C)
• Power supply | (10–15 V)
• Power consumption | (<4 W)
• Weight: sensor with support and 5 meters cable | (3.3 kg)
• Weight: electronic unit with battery | (3.8 kg)
• Weight:GPS antenna with 15 m cable | (0.7 kg)

Additional Information: