By consolidating the PROTEM receiver and TEM47 transmitter components into a single console, the PROTEM CM system offers significant improvements in portability and convenience: As compared to the individual receiver and transmitter components, the PROTEM CM is both smaller in size, and less in weight by about half. The increase in component portability will be of particular benefit for surveys in more demanding environments, both in-mine and over rugged terrain.

Available with cable reference synchronization only, for either single component or sequential three-component data collection, the system otherwise offers the same functions and performance characteristics as the standard PROTEM 47 components, and is compatible with all other Geonics transmitters.

For greater depth of exploration, a high power (HP) modification to increase the output current from the transmitter section is available as an option.


Technical Specifications

Powe source : Internal 12/24 V rechargeable lithium-ion battery
Battery life : 8 h continuous operation with 2 A transmitter current at 12 V output voltage
Operating temperature: -30°C to +50°C
Dimensions : 40 x 35 x 24 cm
Weight : CM: 10.5 kg; CM HP: 11.7 kg

Manufacturer: Geonics


Receiver section

Measured quantities : Rate of decay of induced magnetic field along 3 axes
Time gates : 20 or 30 geometrically spaced gates for each base frequency, range from 6 μs to 800 ms
Base frequency : 0.3, 0.75, 3, 7.5, 30, 75, 285 Hz, or 0.25, 0.625, 2.5, 6.25, 25, 62.5, 237.5 Hz
Dynamic range : 29 bits (175 dB) including all gains
Synchronization: Internal terminals provided for cable reference with external transmitters
Data output : RS-232 serial, USB ports

Transmitter section 

Current waweform : Bipolar rectangular current with 50% duty cycle
Base frequency : 30, 75, or 285 Hz (60 Hz power line frequency) / 25, 62.5, or 237.5 Hz (50 Hz power line frequency)
Turn-off time :  2.5 μs at 2 A into 40 x 40 m loop; faster into smaller loop
Transmitter loop : Any dimension from 5 x 5 m to 200 x 200 m; multiple-turn loops possible, from 1 x 1 m
Output voltage: CM: 0 to 9 V continuously adjustable (at 1 A load), or 24 V, CM HP: 12 to 36 V with external batteries
Output current : CM: 3.5 A maximum (7 A pp) with internal battery, CM HP: 11 A maximum (22 A pp) with external batteries