Geometrics Magnetometer 858

Basic information on each piece of equipment
ARF Checkout: 
File 858Manual_D_english.pdf28/06/10 2:07 pm3.64 MB
File 858Manual_D_español.pdf10/07/08 2:01 pm1.43 MB
File Breiner1973 - Applications Manual for Portable Magnetometers.pdf10/07/08 2:01 pm7.06 MB
File MagMap2000Manual.pdf10/07/08 2:01 pm7.16 MB

Note that the photo shows a single-head magnetometer. Our device has two cesium heads (gradiometer).

Weight and dimensions (in hardcase): 78 x 36 x 26 cm, 29 Kg (63.3 lbs)

MagMap2000 software is free online at this link:

Discussing the longevity of the instrument with Don Pierce, Geometrics Customer Support, (408) 428-4210.

Inside the sensor the lamp is epoxied to a stand and this epoxy can break if the unit is dropped or otherwise subjected to shock. Now they are using a different epoxy that doesn't break down as quickly.

Mag Diagnostics Test window:
RF 1,2 (frequency control) should be under 60% (preferably 30-40%)
Brightness: should be 50% (+/- 5%)
Cold: 50%
Signal: dependant on where you are (not as good for general diagnostics).

Battery shelf-life is 3-5 yrs depending on how they're used (condition the batteries by giving them a full charge every 6 mo).