Measurand's SAAV is designed to take on a cyclical shape around the inside of the casing as it is installed. To ensure the SAAV is properly seated in the correct cyclical shape, Measurand recommends lifting and pumping it in the casing prior to applying final compression. Measurand also recommends verifying that the SAAV has taken the appropriate cyclical shape by using the SAAV Installation Verification tool in our SAARecorder application.

WARNING: If you are installing a ShapeArray™ instrument in Low Power Mode for use with certain low power data loggers, then you will need to be using a model 004 SAAFPU interface with at least revision R.4B or a model 002 SAA232 interface with revision R.2B. Older interfaces are NOT supported. While the SAAV Installation Verification diagnostic is open, the instrument will temporarily be placed in regular power mode. When the SAAV Installation Verification window is closed, the instrument will automatically be returned to Low Power mode. Do NOT disconnect the ShapeArray™ instrument from the computer without closing the window or the instrument could be left in regular power mode.

In SAASuite 3.0 or higher, the SAARecorder application is launched by clicking the Manual Data Collection button.

Figure 1: Launch SAARecorder from SAASuite by clicking the Manual Data Collection button

Step 1 - Launch SAARecorder and Connect to the SAAV

First you must connect your computer to the SAAV with an appropriate interface. More information on properly connecting your computer and the SAARecorder application to a Measurand ShapeArray is available in the following articles in our Support web site.

NOTE: A pre-recorded raw data sample from SAARecorder (.RSA) or a Campbell Scientific data logger raw data file (.DAT) can be loaded into verification tool for analysis instead of being directly connected to the instrument. This is described in more detail in Step 3 below. 

Step 2 - Launch the SAAV Installation Verification Tool

Once your computer and SAARecorder are connected to the SAAV, you need to launch the SAAV Installation Verification tool from the Diagnostics menu in SAARecorder.

Figure 2: The SAAV Installation Verification tool is launched from the Diagnostics menu in SAARecorder

Step 3 - Input the Casing's Inner Diameter

In the SAAV Installation Verification window, if you are directly connected to the SAAV, ensure the Live Data option is selected. Alternatively, if you wish to analyze data saved in a raw data file (.RSA or .DAT), then select the Recorded Data option and click the Browse button to select the raw data file. Once your data source is selected, enter the inner diameter of the casing into which the SAAV is being installed in the Casing Inner Diameter field. For standard inclinometer casings we would expect inner diameter values similar to the following.

  • 70 mm outer diameter - 59 mm inner diameter
  • 85 mm outer diameter - 73 mm inner diameter

Figure 3: The casing's inner diameter must be entered into the Casing Inner Diameter field

NOTE: The Casing Inner Diameter value will need to be entered in millimetres or inches depending on SAARecorder's units setting. The units setting can be changed by selecting the SAA Setup | Units menu option.

Step 4 - Determine Whether the SAAV Has Achieved the Proper Cyclical Shape

As the SAAV takes on a cyclical shape within the casing, it will compress. The amount of compression in the instrument will determine how close the instrument is to the ideal cyclical shape within the casing. Pumping the SAAV by lifting it an appropriate height and dropping back into the casing to achieve an appropriate amount of compression will reduce the amount of settlement expected after installation. 

Once the SAAV is resting on the bottom of the borehole and you are connected to it with SAARecorder, lift the ShapeArray until it is hanging in the casing with one segment touching the bottom. When the last segment is resting on the bottom of the casing, the angle reported by the SAAV Installation Verification tool will be around 4° to 6°. The tilts of the segments above the last segment should be close to 0°. If there are bends in the borehole, the angle will increase to 1° or 2°. You should see a graph similar to what is shown in the figure below in the SAAV Installation Verification tool when the instrument has been lifted sufficiently.

Figure 4: The SAAV Installation Verification tool in SAARecorder when the SAAV has been lifted sufficiently

Once you have lifted the SAAV enough to have only the last segment resting on the bottom of the casing, drop the ShapeArray such that it falls straight into the casing. The array will drop into the hole with some friction from the joints resisting the movement. Manually apply some downward pressure to the SAAV (approximately 5 lbs) in order to compress it within the conduit, record the value for Actual Compression reported in the SAAV Installation Verification tool, and collect sample data from SAARecorder

The SAAV should be lifted and dropped repeatedly in this manner until three sequential readings of Actual Compression do not change by more than 1 mm. This should take approximately 10 to 15 lift and drops (pumps). The Average Tilt and green status light may be attained earlier but lifting and dropping the array should continue until the Actual Compression ceases to change by more than 1 mm on three consecutive drops.

NOTE: Save the recorded data files and details about the number of lift and drops were required to achieve proper compression. These files and details could be helpful in troubleshooting any issues encountered in the future.

Once this is done, you will be ready to measure the azimuth offset for the X-mark.

SAAV Installation Verification Tool Elements

The SAAV Installation Verification Tool calculates the compression associated with the ideal cyclical shape of the SAAV within the casing using a theoretical model consisting of perfectly rigid segments and joints. Although the SAAV's joints are flexible, this is a good approximation for installation purposes.

Changing the Casing Inner Diameter value will calculate and display the following compression values for the SAAV.

  • Calculated Compression: The compression associated with the theoretical ideal cyclical shape within the specified casing inner diameter. Calculated compression is determined using the target tilt magnitude calculated for a given casing, the length of the SAAV segments, and the overall length of the SAAV.
  • Actual Compression: The current amount of compression within the SAAV based on the live reading or the raw data file selected. Actual compression is calculated using the measured tilts and segment lengths. When this value is higher than the expected compression, the SAAV is typically well seated.
  • Remaining Required: How much more compression is required to achieve the compression associated with the theoretical ideal cyclical shape.
  • Calculated Potential Settlement: The calculated potential settlement is a conservative measure of the settlement that can remain during the pumping process. This value should be used as a general indication and checked against settlement observed using the extension tubes during the pumping process. It is determined by summing the displacement which would be required to make a segment with tilts lower than the target tilt shift to meet the target tilt.  Since the physical tilts are dependent on the adjacent segments, segments with higher than expected tilts can cause adjoining segments to have lower than expected tilts. Both segments in this case are well seated against the wall, but the tool will estimate that the segment with lower than expected tilt will shift. This means that the calculated potential settlement is likely to be higher than the settlement which can actually take place. 

The dot graph presents the tilt magnitude angle in degrees of each segment in the SAAV relative to the calculated medial axis. The expected average tilt to achieve the Calculated Compression is displayed as a dotted blue line in the graph. 

Figure 5: The dot graph provides a quick visualization of the segment's tilt relative to the medial axis

In the dot graph, green dots to the right of the dotted blue line indicate segments that have achieved a desirable tilt. Red dots to the left of the dotted blue line show segments whose tilts are below the expected average.

The Average Tilt Quality indicator in the bottom right corner of the window displays the average tilt value relative to the medial axis in degrees for all segments and a quality indicator showing a Poor (red light) or Good (green light) rating. This rating is determined by the number of segments that have not reached the expected average tilt and their proximity to the expected average tilt and should be used as general guideline only. The SAAV should be pumped until three sequential readings of Actual Compression do not change by more than 1 mm.

Figure 6: The Average Tilt Quality indicator indicating that most of the segments have reached ideal tilts