Syscal Pro
from Iris Instruments

The Syscal Pro is an all-in-one multinode resistivity imaging system for environmental and engineering geophysical studies. It features internal switching board for 48 (Switch-48) up to 120 (Switch-120) electrodes, 10 of which can be addressed simultaneously depending on the array type being used, and an internal 250W power source.

Syscal Pro setup, including external Tx battery.
Syscal Pro setup, including external Tx battery.

The output current is automatically adjusted (automatic ranging) to optimise the input voltage values and ensure the best measurement quality. The system is designed to automatically perform pre-defined sets of resistivity measurements with roll-along capability. Two strings of cable with 24 electrode take-out’s each (or 36) are connected to the back of the resistivity meter. Made of heavy duty seismic cable, these strings are available with standard 5 or 10 m electrode spacings. Customised cables may also be assembled for special arrays or non-standard applications.

Measurement sequences can be configured through the instrument interface or via the PC software package Electre Pro. Electre Pro enables operators to develop and interrogate 2D, 3D, downhole and roll long sequences prior to heading into the field, helping to minimise potential data collection errors.

Compact, easy-to-use and field proof, the Syscal Pro measures both resistivity and chargeability (IP). It is ideal for environmental and civil engineering applications such as pollution monitoring and mapping, salinity control, depth-to-rock determination and weathered bedrock mapping. It can also be used for shallow groundwater exploration (depth and thickness of aquifers).

With the Syscal Pro, resistivity surveys can be performed very efficiently with one operator only, as surveys can be conducted in a fraction of the time it takes to acquire data with single channel instruments, you can afford to stack a greater number of times or increase the polarising and measuring time, or acquire more than one array type and combine them in data processing stage. All these help you acquire better quality field data.

The well-known reliability and accuracy of the Syscal range of resistivity meters will also mean extra value both for the contractor and the results end-user.

Product Dimensions

Physical Dimensions (L x W x H) Weight
Syscal Pro (instrument only) 31cm x 23cm x 36cm 13kg

Technical Specifications

Voltage: Up to 800V in switch mode and 1000V in manual mode
Current: 2.5A
Power: 250W off 12V battery.
Pulse Duration: 0.2s, 0.5s, 1s, 2s, 4s, or 8s
Channels: 10 recording channels
Input Impedance: 100Mohm
Max Voltage (across recording channels): 15V
Protection: Up to 1000V
Accuracy: 0.2%
Resolution: 1 microV
Readings: Current, Voltage, standard deviation and 20 IP windows (pre-set or selectable)
Stacking: User selectable stack threshold based off measurement standard deviation.
Noise Rejection Routines: 50 & 60Hz noise rejection. SP linear drift correction.
Memory: 21,000 readings, stored on solid state memory
GPS: NMEA GGA sentence via RS232
Temperature: -20 to +70ºC


Contents Dimensions (L x W x H) Weight
Case 1
Syscal Pro
38cm x 30cm x 58cm 27kg
4 x cable reels 54cm x 42cm x 22cm (each reel) 23kg (each reel)
2 x Metal box
80 Electrodes
25cm x 11cm x 39cm (each box) 23kg (each box)
Shipping Notes:

For over seas rentals the equipment will be shipped on a pallet (120cmx100cmx95cm 175kg)

Application Notes

Geotechnical Engineering

ERT can be used to complement traditional geotechnical bedrock topography mapping methods to provide additional information and verify the borehole results. In some cases the presence of weathered rocks can stop the drill before the rock is completely impermeable giving a false depth of bedrock. ERT can help to differentiate between weathered rocks and bedrock, allowing a more accurate estimation of topography from a continuous profile. It can also be used to successfully identify geological features such as faults and dykes. For fault investigation an array with good vertical resolution would be needed such as the Wenner array.

A cavity would produce a resistivity anomaly which varies depending on its contents; it might be empty or filled/partly filled with water or other material. The resulting resistivity anomaly depends on the composition of the material in the cavity so it may be very conductive to relatively resistive compared to the host rock.


The Syscal Pro can be used in archaeological prospecting to detect the location of ditches, walls, palaeochannels and even internal structures in mounds. It would typically be used when there is an extensive area to be investigated and/or the ground is too conductive to use GPR.


The Syscal Pro can be extremely useful in hydrological applications. To locate groundwater in a location where it can reasonably be assumed that there is no lateral variation of resistivity, the best method is to use electrical resistivity sounding. If there are lateral variations in groundwater level due to more complex geology then electrical resistivity tomography would be the more appropriate method, as this can detect the groundwater depth as well as any fractures in the aquifer which is critical in being able to assess the best location for drilling. The high power of the Syscal Pro makes it ideal for either shallow or deep aquifer detection and characterisation.