Configure the EM31 Survey Setup Menu on Archer.
1. Using the stylus, select the Survey Setup Menu.
2. Select the EM31 Mode.
Pick from one of three modes: auto, wheel, or manual. In Auto Mode, readings will be automatically recorded at a specified frequency. Only one dipole mode, vertical or horizontal, can be selected. AUto mode is often used in conjunction with a GPS. In Wheel Mode, readings are triggered at intervals determined by the user and an odometer at the EM31-MK2′s wheel base. (Note: KD Jones Instruments does not rent the wheel accessory.) In the Manual Mode, readings are manually triggered by the user. Manual mode is very often used for survey grids or lines. Make note that when Manual mode is selected, the option Reading/s changes to the option labeled Samples/Rdg.
In the Auto Mode, the user must select the number of Samples/Rdg. The Samples/Rdg Field is the number of readings the EM31-MK2 will take per second. Any number above zero can be entered but since the EM31-MK2 has a fixed frequency of data output at 11 readings per second, any value entered will be rounded to the nearest base frequency of the EM31. For example, an entered value of 10 will result in 11 readings.
In the Manual Mode, enter any positive value into the Samples/Rdg Field. This field is the number of readings that will be taken after the trigger is pressed. After the EM31-MK2 is done taking a reading it will beep, average its readings, and plot the data on the screen. The EM31-MK2 can take 10 readings per second.
3. Select the Component Field to be recorded and displayed.
The Component Menu determines whether the EM31-MK2 is running Inphase or Both. If the Inphase option is selected, the Comp option must be indicated on the instrument panel. Likewise, if the Both Option is selected on the Allegro, the instrument panel must be set to OPER.
When the Both Option is selected, conductivity and inphase will be measured and displayed on the Allegro.
4. Select the Dipole Mode.
In Manual Mode, select either Horizontal , Vertical, or Both. In the Auto or Wheel Modes, select either Horizontal or Vertical. Horizontal dipole readings will reach a maximum depth 1.5 times the intercoil spacing while the vertical dipole readings will reach a maximum depth of .75 the intercoil spacing.
5.The Survey Line is the name given to each survey line.
Generally these are coordinates of the survey. If the user names the Survey Line by a number, the EM31-MK2 program will automatically name each subsequent line a new number based on the Line Increment. The Line Increment is the distance in which Survey Lines will be from one another. For example, if the first Survey Line is named 2.50 (Y=2.5) and the Line Increment is 2.50, your proceeding lines will be named 5.00, 7.50, 10.00, and so on. In this example, the Start Station and station positions shown during data acquisition would represent a X coordinate along the survey line.
6. The Sequence Field determines whether each line continues the same way or alternates.
determines whether the user is going to conduct each survey line in the same direction (One Way) or alternate the direction of each line (Alternate). Data acquired on a grid is often acquired using the Alternate setting.
7.Select the Line Direction.
Pick North, West, South, or East for the direction of the first line that will be surveyed. If the Sequence is One Way, this setting will stay the same for each data line. If the Sequence is Alternate, the EM31-MK2 will automatically switch the directions for each line with approval. If in doubt and the survey is conducted using a grid, it often works out well for North to represent the direction towards greater positive Y values and East to represent the direction of increasing X values.
8. Select a Start Station.
The Start Station Field is the starting station number for each line. For instance, if the operator is using the imperial measuring system and starting at X=5 feet away Y axis, the operator may want to put in a measurement of 5.00 or take good notes (or both).
If in the Auto Mode or Manual Mode, the user needs to select a Station Increment. The Station Increment Field is in essence the “reading” increment or at what intervals the EM31-MK2 will take recordings. It is also used with the Start Station Field to display information with graphics. If in the Wheel Mode, instead of a Station Increment there will be a Wheel Increment. The wheel increment determines readings depending on how far the EM31 has traveled via odometer. The wheel increments are approximately 20 cm. Again, many rental companies do not provide the wheel attachment for the EM31-MK2.
9. After changing the EM31-MK2 Survey Setup Menu options, it is important to save.
Press the OK Button to save. After pressing the OK Button, it is safe to push the X Button to exit. If the user exits without pushing the OK Button, the changes will not be saved.