MinGeo Cable Declination Inclination Magnetometer (Cable DIM)
The MinGeo Declinometer/Inclinometer (D/I instrument, or Cable DIM) is a
fluxgate magnetometer mounted on a nonmagnetic theodolite. The instrument
is used to perform absolute measurements of declination and inclination.
It makes possible the calibration of compasses and the periodical calibration
of continuously recording variometers of magnetic observatories.
The angle measured from the true north, at which the fluxgate magnetometer
gives the minimum output, is the declination angle. The measurement carried
out using an azimuth mark, the direction of which is known, referring to the
true north. The true north can be determined with the sighting of a true north
reference target at some distance. Alternatively, the true north can be derived
from celestial navigation calculations by the sighting of the Sun or a star.
Zeiss THEO 010/020 optical theodolites are purposefully refurbished by
replacing all steel components with nonmagnetic parts. Then, these nonmagnetic
theodolites are used in the MinGeo D/I Instruments. Following thorough optical
and magnetic tests, a linear core fluxgate magnetometer is mounted on the
telescope, and its magnetic axis is ensured to be parallel to the optical
axis. The magnetic adjustment takes place in the Nagycenk Observatory (NCK),
while the optical calibration is done by an independent geodetical laboratory.
The instrument is delivered with a battery, a battery charger, and calibration
documents. The MinGeo D/I instrument is suitable for both observatory and field use.
Main features:
- Large panel meter features a 31 digit LCD with 19mm (0.75") white digits on a black background
- Improved buzzer to easily find the null positions of the theodolite without having to look at the LCD
- ± 200 nT magnetic range
- 5 m long extension cable
- Rechargeable battery-operated, digital display magnetometer console
- Replaceable 18650 Li-ion 3.7V 2200 (minimum) mAh standard rechargeable battery
- 220V AC mains charger
- MinGeo 10 Cable DIM provides more accurate angle measurement, however the measurement time is longer, since the horizontal and vertical angles cannot be read simultaneously
- MinGeo 20 Cable DIM provides sufficient precision for absolute magnetic observations in shorter time, since the horizontal and vertical angles can be read simultaneously
Applications:
- Earth's magnetic field Measurements
- Reference measurements of the variometers at observatories
- Repeat station survey
- Compass & rangefinder calibration
- In field referencing in oil and gas exploration
Main technical parameters:
- Angular measuring accuracy
Theo-10 * Theo-20 Circle division 0.2 gon (20') 1.0 gon (1º) Micrometer scale division 0.2 mgon (1") 0.01 gon (1') Angular reading estimation 0.02 mgon (0.1") 2 mgon (0.1') Mean sq. error of direction measured face left/face right ± 0.3 mgon (± 1.0") ± 1.0 mgon (± 3.0") * Theo-10 - temporary stock shortage may occur
- Magnetic resolution 0.1 nT
- Magnetic scale factor: 1.0 ± 3%
- Fluxgate sensor alignment: less than ± 3' = ± 55.6 mgon
- Instrument offset: less than ± 10nT
- Instrument operation time: 10+ hours
- Operating temperature: -10 ºC to +45 ºC
- Achievable measurement accuracy: maximum low frequency error between absolute magnetic observations ± 2.5 nT
Standard accessories:
- Steep sighting prism set for the telescope and microsccope
- Sunfilter for telescope
- Simple nonmagnetic servicing tools
- Plummet
- Universal charger (mains/5V DC)
- Plastic transport case
- Certificates and manuals on stick
Optional accessories:
- Microscope diagonal eyepiece (at around the Equator)
- Wooden steel-free tripod (for field use)
- Tablet (on request) necessary requirements Android 10, GPS, Bluetooth 4.0 BLE, 10" display with 1920x1280 resolution,
- Enables manual input of scalar magnetometer data
- GSM90 or GSM19 scalar magnetometer can be connected using USB-Serial converter (optional)
- DIM Android application software
- Manual angular & magnetic data recording
- Autofill for predictable angles at the steps of 'null' and 'residual' methods
- Automatic Magnetic Meridian Calculation
- Output angular formats: 'gon' or 'dms'
- Azimuth Geographic True North calculator
Dimensions
- Height of instrument: 33.4 cm
- Container: 55x65x35 cm
- Tripod: 16x16x160 cm
Weight
- Instrument: 4.8 kg
- Instrument in metal container: 9.2 kg
- Tripod: 5.6 kg
