MiniSting R1™

Electrical Resistivity Meter

The MiniSting R1 is a high-powered, induced polarization (IP) and electrical resistivity instrument used for testing grounding grids, soil resistivity testing for corrosion protection design, and more. This single-channel tool is engineered to be the best tool for manual resistivity jobs—ease of use, low cost, and high accuracy make it ideal for low-manpower explorations and educational and training demonstrations.

MiniSting Use Cases

The MiniSting geophysical instrument is recommended for vertical electrical sounding (VES), profiling, the IEEE fall-off-potential (FOP) method, and the four-pin Wenner soil test (ASTM G57) for soil resistivity.

 

It is versatile enough for both water and earth uses, including:

  • Groundwater Investigation

  • Cathodic Protection Design

  • Grounding Studies

  • Soil Tests

Features

  • Small, but mighty. This high-powered, lightweight tool has a built-in rechargeable NiMH battery—you can get a day’s worth of manual surveying from one charge. The system includes a battery charger.

  • An easy-to-use, menu-driven system. Recorded data is saved in the internal memory and at a convenient time downloaded to a computer for further processing. Our utility software, The Administrator, is included with the MiniSting as well as a serial download cable with a USB adapter. The Administrator software is used for data download.

  • Rugged construction. Whether you’re working in the swamp or the desert, the MiniSting is versatile enough to withstand harsh climates and provide accurate data.

  • Versatile. The MiniSting reports in feet or meter: For example, the Wenner 4-pin method is typically specified for Wenner spacing in feet, but the reporting is required in Ohm Centimeter. Simply set the MiniSting for feet before surveying, and switch to meter after the survey before you download the data. Then move the decimal point two steps to the right to get Ohm Centimeter. This instrument can be configured in several ways depending on what you are measuring.

  • Pairs seamlessly with AGI tools for immediate results. For example, you can get more from your data when you pair the MiniSting with the EarthImager 1D—in addition to empirical calculations, you’ll also get modeled calculations that represent true resistivity, layer thickness, and depth to each layer so you can use your results and immediately take next steps with certainty.

The MiniSting is preprogrammed in manual measurement mode for the following arrays:  

Product Details



Measurement Modes

Apparent resistivity, resistance, voltage (SP), induced polarization (IP), and battery voltage.

Measurement Range

400 Kohms to 0.1 milliohms (resistance).

0-500 V full-scale voltage autoranging.

Measuring Resolution

Max 30 nV—depends on voltage level.

Screen Resolution

4 digits in engineering notation.

Output Current

1-2-5-10-20-50-100-200-500 mA.

Output Voltage

The user can switch between high and low voltage limit for the transmitter (800 Vp-p or 320 Vp-p voltage limit). Actual electrode voltage depends on transmitted current and ground resistivity.

Input Gain Ranging

Automatic. Always uses full dynamic range of receiver.

Input Impedance

>20 MOhm.

Input Voltage

Max 500 V.

SP Compensation

Automatic cancellation of SP voltages during resistivity measurement. Constant and linearly varying SP cancels completely.

Type Of IP Measurement

Time domain chargeability (M). Six time slots measured and stored in memory.

IP Current Transmission

ON+, OFF, ON-, OFF.

IP Cycle Times

1, 2, 4, and 8 s.

Measure Cycles

Running average of measurement displayed after each cycle. Automatic cycle stops when reading errors fall below user set limit or user set max cycles are done.

Cycle Times

Basic measure time is 1.2, 3.6, 7.2, or 14.4 s, as selected by user via keyboard. Autoranging and commutation adds about 1.4 s.

Signal Processing

Continuous averaging after each complete cycle. Noise errors calculated and displayed as percentage of reading. Reading displayed as resistance (dV/I) and apparent resistivity (Ohmm). Resistivity is calculated using user-entered electrode distances.

Noise Suppression

  • Better than 100 dB at f>20 Hz.

  • Better than 120 dB at power line frequencies (16 2/3, 20, 50, and 60 Hz).

Total Accuracy

Better than 1% of reading in most cases (lab measurements). Field measurement accuracy depends on ground noise and resistivity. Instrument will calculate and display running estimate of measuring accuracy.

System Calibration

Calibration is done digitally by the microprocessor based on correction values stored in memory.

Supported Configurations

Resistance, Schlumberger, Wenner, dipole-dipole, pole-dipole, pole-pole, azimuthal, mise-a-la-masse, SP (absolute), and SP (gradient).

Data Storage

Full resolution reading average and error are stored along with user-entered coordinates and time of day for each measurement. Storage is effected automatically.

Memory Capacity

More than 3,000 measuring points can be stored in internal memory.

Data Transmission

RS-232C channel included to dump data from instrument to PC on user command. USB adapter is included for data download to a USB port.

User Controls

  • 20-key-tactile, weather proof keyboard with numeric entry keys and function keys.

  • On/Off switch.

  • Measure button integrated within main keyboard.

  • LCD night-light switch (push to illuminate).

Display

Alphanumeric LCD display (four lines x 20 characters) with night-light.

Connectors

  • 4 banana plug, pole screws for current and potential electrodes.

  • 10-pole KPT connector for external power, RS-232C and synchronization connections.

Power Supply

  • 12V, 4.5 Ah NiMH built-in rechargeable battery.

  • External power connector on front panel. The instrument automatically selects external battery if present.

Operating Time

Depends on conditions. Internal circuitry in auto-mode adjusts current to save energy. At 20 mA output current and 10 kOhm electrode resistance, more than 2,000 cycles are available from a fully charged battery pack.

Battery Charger

Dual-stage charger with switchable input (115/230 V AC at 50-60 cycles).

Weight

6.6 kg (14.5 lb.).

Dimensions

  • Width: 255 mm (10").

  • Length: 255 mm (10").

  • Height: 123 mm (5").