G-824A
from Geometrics
The Geometrics Model G-824A mates the well-proven high-performance caesium sensor with new sensitive internal sensor driver and Larmor counter electronics. Improved low noise amplifiers have now lowered the noise floor to approximately 350 fT (femto-Telsa). This advanced integrated magnetometer provides unmatched versatility in performance, small size, low weight, wide application range and cost effectiveness

The system’s high performance and multi-function capability are excellent for mapping geologic structure for mineral and gas exploration. Rapid sample rates enhance the detection and delineation of targets for environmental, archaeological or UXO and EOD surveys. Detection ranges, classification and precision mapping are improved by the G-824A performance and in some cases provide results not achievable by any other means. The G-824A meets the highest standards for airborne, land or marine surveys meeting rigorous vibration and environmental testing standards.
Gradiometer sensor arrays are particularly effective for geologic mapping and search. The G-824A provides the ability to concatenate RS-232 outputs from up to 8 sensor/counter assemblies into a single digital stream, transmitted up a single cable and record on a single computer serial port. Each of these sensors is synchronized to within 1ms for simultaneous measurement and true gradient measurements.
Product Dimensions
Physical | Dimensions (L x W x H) | Weight |
---|---|---|
G-824A (instrument only) | 45cm x 7cm x 7cm | 2.3kg |
Technical Specifications
Sensor: | Self-oscillating split-beam caesium vapour (non-radioactive). |
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Operating Range: | 20,000 to 100,000 nT. |
Sensitivity: | <0.3 pT/√Hz RMS. Typically 0.01 nT P-P at a 0.02 second (50 Hz) sample rate (90% of all readings falling within the P-P envelope). |
Sample Rate: | 0.001 s (1000Hz) to 15.99s. |
Heading Error: | ±0.15 nT over entire 360º equatorial and polar spins. Not specified on 824B. |
Absolute Accuracy: | <3 nT throughout range |
Communication: | RS-232 data at 115K baud, concatenated data streams from up to 8 sensors depending on sample rate, compressed binary. |
Cable: | Sensor to Electronics- standard 2.77m (other lengths available on request) |
Operating Temperature: | -35ºC to +50ºC |
Storage Temperature: | -45ºC to +70ºC |
Altitude: | 9,000m |
Weatherproof: | O-Ring sealed for operation in rain. |
Power: | 24 to 32 VDC, 2.0 amp at turn-on and 1.0 amp thereafter. |
Shipping
Contents | Dimensions (L x W x H) | Weight |
---|---|---|
Case1
G-824A and cables |
80cm x 50cm x 30cm | 25kg |
Shipping Notes:
US Export licence required.
Data Sheet
- G-824A Datasheet (PDF)
Literature
- Applications Manual for Protable Magnetometers (PDF 1MB)
- Passive Compensation of Aircraft (PDF 266KB)
- Theory of Operation of Caesium Vapour Magnetometers (PDF 122KB)
- Total Field Magnetometers Theory and Applications (PDF 122KB)
Checklists
- Checklist for Data Storage and Transfer (PDF 249KB)
- Checklist for Data Processing (PDF 190KB)
- Checklist for Field Editing (PDF 244KB)
- Checklist for GPS Operating Procedures (PDF 231KB)
- Checklist for Instrument Storage (PDF 138KB)
- Checklist for Out of Box Equipment Tests (PDF 228KB)