UTEM 4 Borehole - Downhole Probe

The UTEM 4 BH system includes a down-hole probe that consists of five modules that are assembled at the hole collar by means of quick locking couplings with double 'o' rings. All listed modules are needed to obtain oriented three component measurements. Additional battery modules can be added to extend continuous measurement time. The UTEM 4 BH output is a serial data stream compatible with the BH UTEM 3 fibre optic data link. The UTEM 4 BH probe incorporates the analog to digital conversion down the hole and much of the data processing and control functions that are normally found in a digital EM receiver.

The UTEM 4 BH probe is designed to be assembled at the hole collar by means of single turn twist lock mating threads. Special collar clamps are used to hole the suspended assembly.

UTEM 4 BH SYSTEM COMPONENTS: (38 mm diameter modules)

  • 3-axis EM (dH/dt) Sensor and Digital Encoder module:
    • coincident measurement point
    • simultaneous measurements
    • proprietary 3-component sigma-delta digital encoder
    • field nulling feedback design
    • sensor length: 112 cm
    • overall module length: 164 cm
    • effective area axial: 165 m2
    • effective area transverse components: 55 m2
  • 3-axis magnetometer and 3-axis accelerometer (with digital encoder) module:
    • 3-axis ring core flux gate magnetometer
    • 3-axis micro-machined accelerometers
    • temperature sensor (+0.02C with deconvolution)
    • multiplexed multi-channel digital encoder
    • data decimation and preprocessing
    • data compression
    • serial multiplexing and packed formatting
    • gain/power supply/motion sensing/options controller
    • 2 hour battery warning
    • fibre optic data stream encoding
    • power supplies
    • length: 131 cm
  • Battery module:
    • 4.4 Amp-hours/12 Volt rechargeable battery packs (2)
    • battery life: >15 hrs continuous operation
    • additional modules can be stacked for survey time
    • length: 130 cm
  • Caliper Wheeled Motion Detector module
    • sends motion signals to controller
    • triggers power supply turn off in default mode
    • remote setting of down-hole controller options
    • prevents severe probe rolling
    • length: 85 cm
  • Wheeled Shock Absorber module:
    • reduced friction for shallow dip holes
    • shock absorbing plunger
    • length: 45 cm

Complete UTEM 4 BH Probe Assembly:

  • length: 5.7 m (single battery configuration
  • weight: 14.2 kg (8.6 kg with buoyancy)