Elrec 2

Lightweight Two-channel
IP and Resistivity Receiver

Two receiver dipoles
Four chargeability windows
High accuracy and sensitivity

ELREC-2 is a two dipole Time Domain Induced Polarization receiver designed for deep resistivity sounding and high productivity surveys in mineral exploration. It has been designed for being both a user friendly and a very sensitive IP receiver. The ELREC-2 measuring process has been optimized to provide the best possible accuracy in real field conditions.

Main qualities of the ELREC-2

RELIABILITY
- Automatic synchronization with the transmission signal through a waveform recognition process ; besides it automatically resynchronizes at each new pulse to avoid errors due to a possible shift in the period of the transmitted signal.
- Noise monitoring function enabling the operator to check the level of noise observed on each dipole before the measurement : the digital voltmeter function displays on the LCD the raw instantaneous value of potential. In particular, it is possible to numerically observe the presence of a pulse square waveform corresponding to a primary voltage signal and showing the operation of a transmitter. This function is also available during the acquisition of a reading.

ACCURACY
- Automatic SP compensation, including linear drift correction (up to 1 mV/s) through a digital filter.
- Low-pass analog filter, which reduces the effect of higher frequency natural cultural noises (50-60 Hz).
- Automatic digital stacking to enhance the signal-to-noise ratio for as long as the operator wants, with a maximum of 250 stacks.

OPTIMIZATION
- Continuous quality test procedure, which stops the averaging process when the noise level becomes too high, but keeps the previously stacked data. The averaging procedure starts again when the noise decreases.

Applications

Mining exploration
Groundwater exploration
Geothermal exploration
Environmental studies
Civil engineering
Structural geological investigation

Technical Characteristics

Input channels		2
Input impedance		10 Mohms
Input voltage range		each dipole : 5 V max
Automatic SP bucking		±5 V with linear drift correction up to 1 mV/s
Converters		20 bits AD
Power line rejection		50 to 60 Hz
Sampling rate		10 ms
Common mode rejection		86 dB (for RS = 0)

Automatic measuring process : a microprocessor fully controls the synchronization, the gain ranging, the stacking, and the display of the results including the apparent resistivity
Computation of apparent resistivity, average chargeability and standard deviation
Grounding resistance measurement from 0.1 to 1000 Kohms (Line check / ground resistance measurement that permits to check that the electrodes are properly connected to the receiver)
Battery test : manual and automatic before each measurement
Memory capacity : 1022 readings
RS 232 link for data transfer to micro computers and printers (300 to 19 200 bauds rate)
Remote control through the serial link

Operating Mode

Signal waveform		Time Domain (ON+, OFF, ON-, OFF) with pulse duration of 0.5, 1 or 2 seconds
IP chargeability windows		Preset or fully Programmable by the user
Primary voltage		resolution : 1 µV after stacking, accuracy : typ. 0,3 %
Chargeability		resolution : 0.1 mV/V, accuracy : 1 % of displayed value

The chargeabilities and the standard deviations of both dipoles are displayed during and after the acquisition for a real time monitoring of the quality of the on-going readings.
A Normalized chargeability option : the Normalized option refers the chargeability to a standard IP decay curve, and permits to point out any EM coupling effect on the measured signal.

General Features

Dimensions		31x21x21 cm
Weight		6 kg with dry cells
Operating temperature		-40°C to +70°C
Power supply		six 1,5 V D-size dry cells
Field proof Instrument		ELREC-2 operates in a wide temperature range and features a fiberglass case for resisting to field shocks and vibrations.

Ordering Information

Description		Order Number
Elrec 2		530-400-0889IP2

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