IRIS Instruments

Elrec Terra Std./Switch

Elrec Pro
Elrec Pro

The combination of recent electronics with 30 years of know-how

The Elrec Terra is a 20 channel Induced Polarisation (IP) and Resistivity receiver designed to improve productivity and accuracy. This new generation of IP receiver mixes recent electronics advances
with the standards of IP receivers designed by IRIS Instruments since more than 30 years such as robustnesscompactness, light weight and large temperature range.

Exceptional data quality: The Elrec Terra features 20 channels measured with a 24 bits converter giving 31 effective bits measurement (at 100 Hz). This new generation of IP receiver allows to measure accurately IP signal with few mV of reception.

Color touch screen: The graphic color screen allow the user to clearly visualize the 20 IP decay curves at the same time and the pseudo-section of resistivity during the measurement. For a better experience of navigation in the menus and of text writing, the screen can be set as touchable.

Automatic recording of full waveform data: The Elrec Terra automatically records the 20 channel voltage timeseries in background . It allows if necessary to visualize and to reprocess your dataset a posteriori on a laptop with a free dedicated software (FullWave Viewer).

Scalability: The Elrec Terra exists both in standard or switch mode (48 to 120 electrodes in a unique box). An Elrec Terra standard can also be connected to one or several Switch Terra unit(s) (48 to 240 electrodes in a unique box) to be used in switch configuration. Connect two Elrec Terra Switch in master-slave mode to increase your total number of electrodes (2 Elrec Terra Switch 48 become an Elrec Terra Switch 96)

Update and test the Elrec by yourself:  Perform selftest by yourself (calibration and switch board testing) using specific tools provided with the system. Update the Elrec Terra's firmware by yourself for free during the entire lifetime of the system to benefit f rom new developments.

A multitude of interesting features: such as removable Li-ion batteries for an easier shipping and replacement, external battery powering possibility, removable/adaptable signal filters, decay curves stored with one sample every 10 ms (full decay curve), datafiles download on a USB key or by WiFi from laptop or any smartphone or tablet, internal GPS included and automatic handle of local and global coordinates to visualize your profiles on Google Earth, and a lot of other options to discover.

On-time IP acquisition mode: Used together with the TIP 6000 transmitter, this mode allows to reduce by two the acquisition time of your survey while multiplying by two the IP signal.
Hereunder is a comparison of 50% duty-cycle (standard acquisition mode) and 100% duty-cycle (on-time IP) showing the similarity between the two inverted sections. Let's discover this new functionality in the datasheet of the Elrec Terra Std./Switch.

100% duty-cycle



Prosys II

Resistivity data management

Electre Pro

Sequence management for Multi-Electrode units

Fullwave viewer

FullWaveViewer is a software allowing to transfer, display and process a time series IP data


ERTLab 3d Electrical Resistivity Tomography Software



Pulse duration: 

1s, 2s, 4s, or 8s


20 channels galvanically isolated

Input Impedance: 

100 MOhms

Input Voltage: 

15 V on channel 1 & 15 V on the sum of channel 2 to 20, automatic gain, input protection 1000V 

1 µV / 0.2%

Resolution / Accuracy: 


GPS input for coordinates,and synchronisation


Resistivity, Self potentiel, Induced polarisation ( Up to 20 windows), Quality control, and full waveform

Noise Rejection: 

Power line rejection 50 or 60 Hz, SP linear drift correction.

IP mode: 

On-time (100% duty-cycle) and off-time (50% duty-cycle) modes

AD Converter / Dynamic range: 

24 bits / 31 bits


2 Gb + USB port external memory (up to 1 Tb)

Dimensions Elrec Terra Std.

(L x W x H)



7 Kg with internal batteries

Operating Temp.: 

-20 to +60°C


Datasheet Elrec Terra Std./Switch
Principles of geophysical methods for groundwater investigations
Master curves for schlumberger sounding interpretation

IRIS Instruments
1 Av. Buffon 45100 Orléans, France
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