Electro prospecting equipment

Low-frequency electrometry equipment ERP-1

(Manufacturer – MPP “Line”, Sevastopol)
Portable digital equipment ERP-1 is designed to perform geophysical observations methods:
– electrical prospecting by a resistance method by direct and alternating current (VES, EP, MG, MS, and the measurement of full vector of the electric field – vector survey)
– self potential method (SP)
– induced polarization method (IP)

Main specifications

Ambient temperature: from -30 up to + 40 C
Spray-protective and shock-protective design
Calibration of the internal source of test signal
Possibility of joint calibration of the generator and measuring unit by reference resistor
Equipment is designed with micro- controllers using and is managed via program
Generator and measuring unit synchronization is carried out via cable

Generator ERP-1

Maximal output voltage of 300 V
Maximal output power 30W
Output current shape – meander and DC
Operating frequencies: 0, 1.22, 2.44, 4.88 Hz
Output current 1, 2, 5, 10, 20, 50 and 100 mA
Output current stability – not worse than 1%
Supply voltage ~ 12 V (9.5 V minimum, 15.5 V maximum)
Weight (with batteries) 3.5-4.4 kg (depending on the battery)
The battery capacity – 2 Ah or 4 (according to customer’s choice)
Possibility to use an external power supply with voltage of 12 V
Calibration voltage output from 1 Ohm resistor

Measuring unit ERP-1
Operating frequencies of 0, 1.22, 2.44, 4.88 Hz
Input impedance not less than 10 MOhm
Maximum input signal 5 V
The quality factor(Q-ratio) of the analog filter – 18
Interference 50 Hz dumping at least 80 dB
Own noise level not exceeding 0.2 µV
Sensitivity 1 µv
RS232C interface type
Built-in memory capacity 8 MB (up to 70 000 measurements)
Weight with batteries 3.2 kg
Backlight LCD display

Switch channels and cables for multi-electrode electrical tomography

Equipment kit includes also a mechanical switchboard of channel and multi-electrode cable set, allowing connection up to 48 electrodes to the generator output and to the measuring unit input without electrode installation changing. Multi-electrode cable consist of two sections with electrode step 5 m, that allows to implement alternating displacement of the sections along line, if it length exceed the length of an one installation.

High frequency kit for micro-VES MEGGER det4/5

Technical specifications

The ranges of measured resistance of the soil
0.01 Ω-19.99 Ω
Ω 0,1 – 199,9 Ω
1 Ω – kΩ 1,999
10 Ω – kΩ 19,99
Measurement accuracy (23°C ±2°C)
±2 % of the read value of ±3 decimal digits. Total measurement error ±5% of read value ±3 decimal digits
Conformity to standards
BS 7430 (1992), BS 7671 (1992), NFC 15-100, VDE 0413 Part 7 (1982), IEC364
Measuring frequency
128 Hz ± 0.5 Hz
Measurement current value
The range of 20 Ω and 10 mA a.c. rms
Range 200 Ω 1 mA a.c. rms
The range of 2k Ω and 20k Ω 100 µA a.c. rms
Short – circuit current – constant in all ranges
Noise
Electrical interference with a peak voltage of 40 V at frequencies 50 Hz, 60Hz, 200 Hz or 16 2/3 Hz potential current causes an error of ±1% of the read value in the range 20 Ω – 2 kΩ. If the noise indicator does not give indications, the maximum error of the interfering voltage in these ranges does not exceed ±2%. In the range of 20 kΩ this error is reduced to a peak voltage of 32V.
Maximum ground resistance current
The ground resistance, which gives an additional error 1%:
The range of 20 Ω -o 4 kΩ
Range 200 Ω – 40 kΩ
The range of 2kΩ and 20kΩ – 400 kΩ
This is resistance of grounding devices, but measured resistances should be subtracted from these values. If the Rc indicator does not give readings, the maximum error will not exceed 2% of maximal resistance of the potential electrode
The maximum output voltage of 50 V
Display
3 ½ digits, maximum reading value of 1999
Protection against environmental influences IP54
Temperature affection
<±0,1% / °C at temperatures above -15 ° C to + 55°C
Temperature range:
ambient 0°C- + 55°C
storage -40°C- + 70°C (without batteries)
Humidity
90% RH at +45°C
storage is 70% RH at +55°C
Protection against external voltage
Supply
Built-in 12V rechargeable battery

Electrical signals measuring device DATAQ DI-245

High-sensitivity portable electric signal meter DI-245 is used as a means of measuring low-voltage analog and digital signals with a maximum frequency of up to 2 kHz (one separate channel) and up to 200 Hz (4 channels). The range of the measured voltages switchable from 10 mV to 50 V.
In accordance with the applicable specialized software, the device can be used to survey the natural electric field potential in complete with non-polarized electrodes, when geotechnical boreholes electro-logging, during long-term recording of soil vibrations by electrodynamic seismographs and accelerometers.

Non-polarized electrode filled with a gel solution of copper sulphate, for natural electric field survey at ground (top) and offshore (bottom)