The SAA X-mark Protractor is used to determine alignment of the X-mark with respect to a known azimuth in cases where the ShapeArray (SAA) is completely placed inside the borehole.
For ShapeArrays with one or more magnetometers, it is typically not necessary to use the SAA X-mark Protractor, as the readings are automatically adjusted to correspond to +X = magnetic North. For ShapeArrays with one or more magnetometers, the protractor would only be required if some direction reference (other than magnetic North) were desired.
Step 1 - Place the Square Protractor
Place the square protractor around the PEX at the top of the ShapeArray. Rotate the square protractor until the arrows are pointed to one of the following:
- The expected direction of movement
- Other desired heading of the ShapeArray
- Other job site datum
Figure 1: The square protractor placed around the PEX at the top of the ShapeArray
If the protractor needs to be placed over the PVC casing rather than the PEX, the required hole size is marked so it can be cut to fit.
Step 2 - Place and Align the Clear Disk
Place the clear disk marker with the X-Line around the PEX on top of the square protractor. Rotate the clear disk around the ShapeArray until the X-Line on the disk and the X-Line on the PEX are aligned.
Figure 2: The clear disk aligned with the X-Lines on the ShapeArray and the square protractor
Step 3 - Read the Angle
Make note of the azimuth offset angle at the X-Line. This will be directly used in the software to rotate the X-mark axis of the ShapeArray towards a known azimuth. For more information, you can refer to the following documentation:
- SAARecorder manual, section SAA Setup | Site Properties
- SAAView manual, section Azi and Aza
- SAACR_raw2data manual, section Selecting Settings