The MiniSting is pre-programmed for Wenner, Schlumberger,
dipole-dipole, pole-dipole, pole-pole, mise-a-la-masse, SP, resistance and
azimuthal surveys in manual measurement mode.
The MiniSting can also be used with the Swift automatic smart electrode
system or with Switch boxes (switching 28, 56, 84 or 98 electrodes) and
passive electrodes or down hole electrode cables. The MiniSting/Swift can
perform automatic surveys with any electrode array and can also also
perform surveys controlled by a computer.
Recorded data is saved in the internal memory and can be downloaded to
a computer for further processing. Utility software ("Administrator") is
included with the MiniSting as well as a serial download cable. The
Administrator software is used for data down-load and command file
up-load.
Resistivity imaging data and bore-hole to bore-hole data can be read
directly by EarthImager 2D software to produce brilliant tomographic
images in color.
The MiniSting has a built in re-chargeable NiMH battery with power
sufficient for one day of manual surveying. The instrument is delivered
with a battery charger. During automatic surveys when the instrument uses
a lot of power, it is normally powered by an external 12 V battery.
| Measurement modes |
Apparent resistivity, resistance, voltage (SP), induced
polarization (IP), battery voltage |
| Measurement range |
400 kOhm to 0.1 milliOhm (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 s, 2 s, 4 s 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 or Ohmft).
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 & 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 3000 measuring points can be stored in internal memory. |
| Data transmission |
RS-232C channel included to dump data from instrument to PC on
user command. |
| Automatic multi-electrodes |
The MiniSting is designed to run dipole-dipole surveys completely
automatic with the optional Swift Dual Mode Automatic Multi-electrode
system (patent 6,404,203). The MiniSting/Swift can run any other array
(Schlumberger, Wenner etc.) by using special user programmed command
files. These files are created in an MS DOS type computer and
downloaded to the MiniSting RAM memory and are later recalled and run
in the field. Therefore there is no need for a fragile computer in the
field. |
| 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 (4 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, field |
12/24 V DC external power, connector on front panel.
Maximum power output is increased when using 24V supply. |
| 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 kW electrode
resistance more than 2000 cycles are available from a fully charged
battery pack. |
| Battery charger |
Dual stage charger with switchable input (115/230 V AC @ 50/60
cycles) |
| Weight |
6.6 kg (14.5 lb.) |
| Dimensions |
Width 255 mm (10"), length 255 mm (10") and height 123 mm (5"). |
