Measured Quantity

Rate of decay of induced magnetic field along 3 axes, in nV/m2

EM Sensor

Air-cored coils

Channels

1 channel used sequentially for 3 components, or 3 channels for 3 component simultaneous operation

Time Gates

20 gates covering 2 time decades or 30 gates covering 3 time decades

Dynamic Range

23 bits (132 dB)

Base Frequency

0.3, 0.75, 3, 7.5, 30, 75 and 285 Hz or
0.25, 0.625, 2.5, 6.25, 25, 62.5 and 237.5 Hz

Integration Time

0.5, 2, 4, 8, 15, 30, 60 or 120 s

Display

240 x 64 dot graphic LCD

Data Handling

Solid-state memory for 3,300 data-sets, RS232 output

Synchronisation

Reference cable or, optionally, highly stable quartz crystal

Power Supply

12 V rechargeable battery for 8 h continuous operation

Weight

15 kg

Dimensions

34 x 38 x 27 cm

Current Waveform

Bipolar rectangular current with 50% duty cycle

Base Frequency

30, 75 or 285 Hz where powerline frequency is 60 Hz
25, 62.5 or 237.5 Hz where powerline frequency is 50 Hz

Turn-Off Time

2.5 us at 3A into 40 x 40 m loop. Faster into smaller loop

Transmitter Loop

5 x 5 to 100 x 100 m single turn loop or
5 x 5 m 8-turn loop

Output Voltage

0 9 V, continuously variable

Power Supply

Internal 12 V rechargeable battery

Battery Life

5 h continuous operation at 2A output

Weight

5.3 kg

Dimensions

10.5 x 24 x 32 cm

Current Waveform

Bipolar rectangular current with 50% duty cycle

Base Frequency

3, 7.5 or 30 Hz where powerline frequency is 60 Hz
2.5, 6.25 or 25 Hz where powerline frequency is 50 Hz
Rates below 1 Hz available from Protem Receiver through reference cable

Turn-Off Time

20 to 115 us depending on size, current and number of turns in transmitter loop

Transmitter Loop

Single turn: any dimension; minimum resistance is 0.7 ohms, up to 300 x 600 m. 8-turn; 5 x 5 or 10 x 10 m.

Output Current

25 A maximum

Output Voltage

18 V to 60 V continuous control with motor generator, up to 160 V (3,800 W)

Synchronization

Reference cable or, optionally, quartz crystal

Power Supply

1,800 W, 110/220 V, 50/60 Hz single-phase motor generator or, optionally multiple 12 V batteries

Transmitter Protection

Electronic and electromechanical protection short circuit

Transmitter Weight

15 kg

Transmitter Dimensions

43 x 25 x 25 cm

Current Waveform

Bipolar rectangular current with 50% duty cycle

Base Frequency

0.3, 0.75, 3, 7.5 or 30 Hz where powerline frequency is 60 Hz
0.25, 0.625, 2.5 or 25 Hz where powerline frequency is 50 Hz
Rates below 1 Hz available from Protem Receiver through reference cable

Turn-Off Time

20 to 750 us depending on transmitter loop size, current and number of turns.

Transmitter Loop

Up to 2,000 x 2,000 m minimum

Output Current

25 A maximum

Output Voltage

18 to 150 V continuously adjustable

Synchronization

Reference cable or, optionally, quartz crystal

Power Supply

4,500 W, 115 or 110/220 V, 50/60 Hz single-phase with 8 h continuous operation motor generator

Transmitter Protection

Electronic and electromechanical protection short circuit

Transmitter Weight

15 kg (TEM-57 MK. 2); 12 kg (TEM-67 power module)

Transmitter Dimensions

43 x 25 x 25 cm (TEM-57 Mk. 2); 42 x 20 x 31 cm (TEM-67 power module)

Motor Generator Weight

62 kg

Motor Generator Dimensions

60 x 50 x 49 cm