Follow the steps below to perform the Wenner Four-Electrode ASTM G57 method with the SuperSting™
For more background on the Wenner Method & ASTM G57, visit this article.
If you would like to perform this method using the MiniSting™, visit this article.
Wenner Four-Electrode method using the SuperSting™:
- Make sure you power your SuperSting™ with an isolated deep cycle marine batter or use a small generator with the SuperSting™ AC/DC Power Supply
- If using the latest SuperSting™ you will need to connect one of the plugs on the top(female or male). The pre 2012 units look like THIS and have ABMN mounted on the faceplate which led to more required cleaning and maintenance. Prior models will have ABMN ports on the faceplate or an ABMN adapter cable. Do not connect to the Receiver Test or IP Simulator!
- Turn on your SuperSting™ and go to the main menu on the SuperSting™ or your tablet controller if you're using a SuperSting™ Wifi. It is more efficient to use the tablet primarily to upload/download of data and use the console keypad for this type of measurement.
- Press 2 to enter Manual Mode.
- Press 3 for Wenner.
- Press 2 to create a data file. Enter a file name. (We suggest storing all data for a Wenner project in 1 file and recording the Record# on field sheets).
- Select what unit of measurement you want to use (Feet or Meters)
Note: If a-spacing is not updated on each reading, the ohm-m/ohm-ft will not be correct. Update the a-spacing on each new electrode placement as per the Wenner array shown below and your projects a-spacing requirements (each project will be specific).
Raw Data Download for Additional QA/QC
Some projects may require a backup of the data or additional QA/QC parameters. The output/source/drive voltage is one value that is sometimes requested. The STG file must be downloaded to check the Hvolt column and to double check manual annotations. It is common to take several readings at each a-spacing so the final record # displayed on the screen needs to be logged by the operators to cross link later to the STG file. The minimum data needed is V/I and a-spacing with the error threshold accepted like 2% standard deviation. Download details are found here for older serial PC COM and here for Android App.
Android will store the files HERE.
The downloaded file will be in STG format and have these HEADERS
Handling these file extensions on Windows 7, 10 and 11 is easier with this View Change.
Reducing Noise
Over 80% of noisy readings in this procedure are caused by high contact resistance and/or damaged connectors or wire.
Extremely narrow electrode/pin spacing (<3 ft)will need the current temporally stepped down as shown HERE to avoid error codes.
Check your Reels and connectors for noise as shown here HERE at each project start.
Reduce noise by checking your contact resistance by reading the CR value on the screen or on some models you will need to run the Contact Resistance Test by going from Main Menu>Test Mode>Contact Resistance and enter a Low =1 and High =2 Measure the contact resistance in ohms and alternate the ABMN wires to check contact at M-N or P1-P2 positions as well as A-B or C1-C2. positions. Make sure the contact is less than 10,000 ohms and ideally less than 1,800 ohms which will allow the boost mode to operate. More details are HERE
Error codes and messages
HVOVL is issued when the SuperSting cannot send out current at A-B (C1-C2). Check for improper connections at the yellow jumper cable from the SuperSting to the Adapter Box on newer systems, disconnected electrode jumpers at the reel and electrode stake/pin, and finally loose stakes/pins in the ground. It is best to lower the contact resistance by wetting the soil around the electrode with water or utilize the methods found HERE. Lower contact resistance raises your signal to noise and so strongly influences data quality.
TXOVL is issued when there is a problem with the transmission of the current after the measurement cycle has started. This can be caused by loose electrode/pin contact in the ground or movements of the electrodes while transmitting. Never touch or add water on electrodes while they are actively measuring! TXOVL can also be caused by a faulty connection somewhere in the AB(C1-C2) circuit. In manual mode methods, the connector clips, wire, banana plugs and loose stakes in the ground are the most common sources. If this is not fixed, the measurement cannot be taken.
INOVL means the input amplifier connected to M-N (P1-P2) has been overloaded. This usually only happens in manual mode measurements if a wire is connected improperly, is shorted/damaged or you are using extremely narrow <3 foot electrode/pin spacings at full output power. HERE is the procedure for extremely narrow spacing. Electrode stakes/pins not firmly planted in the ground typically causes both INOVL and TXOVL error messages. This is often fixed by improving contact resistance as described HERE.
TRANSMITTER OFFLINE !!! This error message is issued when the office power supply is powering the instrument, the firmware cable is attached or if there is a malfunction in the transmitter/instrument communication. More details HERE
TEMP WARM When this warning is issued it is important to make sure the instrument temperature is lowered. By keeping the instrument in shade from direct sun light the internal temperature of the instrument is lowered 10 – 15 °C. It is also a good practice to lower the current setting in case you get a “TEMP WARM” warning. Do not place the instrument directly on hot pavement.
TEMP OVERHEAT If no action is taken and the instrument continues to heat up, a “TEMP OVERHEAT” is displayed and the instrument shuts down and can only be restarted when it has cooled down. Cover the instrument with a tarp from direct sun and do not place it directly on hot pavement.
BLANK SCREEN The LCD is sensitive for temperature and may turn pale or too dark
To adjust the contrast to a suitable level, press the contrast key repeatedly from the main menu (upper right black/white triangle and BSP key). More details are HERE.
To adjust the contrast to a suitable level, press the contrast key repeatedly from the main menu (upper right black/white triangle and BSP key). More details are HERE.