SAAV can be installed in 27 mm ID conduit similar to previous model ShapeArrays. When installing SAAV in this manner, the borehole should be pre-cased with the 27 mm conduit. This installation method is susceptible to buoyancy effects and care must be taken to avoid sinuating the PVC prior to installing the ShapeArray.

NOTE: Measurand highly recommends that users perform a complete diagnostics test on their ShapeArray prior to installation to ensure the instrument is working properly. The .TXT report file generated should be included with the installation log for record keeping purposes. A complete diagnostic report from the time of installation could be required to advance warranty claims should an issue occur in the future. 

The following table outlines the tools and equipment required to install an SAAV into 27 mm ID conduit.

* Starred items are included in the 27 mm ID conduit installation kit

NOTE - Measurand ShapeArrays are shipped on wooden reels with wooden facets stapled to the outside. A pry bar, hammer, and pliers will be required to remove the facets from the reel prior to following the steps below.

The following short video provides a great overview of the installation process. Each step in the installation process is described in more detail following the video.

Step 1 - Choose the Right Conduit

Step 2 - Choose the Right Adhesive  

PVC couplings are attached with PVC solvent cement. In cold temperatures, it is imperative to use an appropriately rated cement. Do not use too much cement, as it can squeeze into the inner part of the conduit. Debur, clean, and use a solvent cleaner on the conduit before applying cement. Most manufacturers specify applying glue to only one surface of the joint.

Figure 2: An example of PVC solvent cement

Step 3 - Prepare the Conduit

All PVC conduit ends should be kept clean from dust, oil, and snow. Look inside the PVC pipes to ensure that no foreign objects are inside the PVC pipe. The edges of conduit over which the ShapeArray is being installed should be smoothed using a deburring tool to prevent abrasion.

Figure 3: Preparing conduit - (a) examples of deburring tools, (b) cleaning and deburring the conduit

Step 4 - Assemble the Conduit  

It is easier to assemble the PVC conduit as it is lowered into the borehole. Using PVC cement and duct tape, secure the end cap onto the bottom-most piece of PVC before inserting it into the borehole. Lower the first piece of PVC conduit then glue the next piece on and tape the joint. Due to buoyancy effects, an assistant will be needed to hold the pieces in place while working. Keep adding more conduit, gluing and taping each joint, until the required length of conduit has been assembled. Glue the bottom part of the top stack included in the SAA Install Kit to the top of the PVC conduit at this time.

Figure 4: Assembling the conduit as it is lowered into the borehole - (a) Assistant holding it in place, (b) next piece glued and taped at the joint

Step 5 - Avoid Buoyancy During Grouting  

A factor which must be considered during installation is the buoyancy of the PVC conduit. Typical grout used for back-filling the PVC conduit has a density ranging between 1,200 kg/m^3 and 1,450 kg/m^3. The grout mix recommended in the Backfilling Recommendations section of the ShapeArray Installation manual has a low density similar to the density of the PVC filled with chain. 

It is important to weight the PVC down rather than allowing it to float up against a hard stop at the top. When the conduit is held from the top, buoyancy causes the conduit to bend and form S-curves making it difficult to insert the ShapeArray. It is recommended that the ShapeArray conduit be weighted down using chain to minimize buoyancy effects. 

WARNING: Do not use water to weigh down the conduit. The water will make it difficult or impossible to insert the ShapeArray into the PVC due to hydraulic forces. If water egress is impeded, the attempt to insert the ShapeArray could lead to hydraulic pressure beyond the pressure ratings of the ShapeArray protective coverings.

The included 1” Pipe Clamp (hanging fixture), should be attached to the PVC below the bottom half of the top stack assembly to ensure that the weighted conduit is suspended at the top of the borehole. Allow the grout to set for 24 hours prior to installing the ShapeArray.

Step 6 - Place the Reel Stand

Figure 6: Place the reel and reel stand approximately 1 m - 1.5 m from the borehole such that the ShapeArray comes off the top of the reel

Step 7 - Lower the ShapeArray Into the Casing

Step 8 - Settle the SAAV to Settle it into the Casing

Once the SAAV is resting on the bottom of the borehole, actions need to be taken to ensure it is properly settled in place. If the instrument is not properly settled in place prior to compressing it, then undesirable displacements will be reported by the instrument as it settles into place naturally. Settlement of the instrument within the casing is not reflective of movement of the casing or the surrounding environment.

To facilitate settling the instrument into place, the SAAV Installation Verification tool included in our SAARecorder software must be used. This tool will display a point graph where each point represents the tilt of a segment relative to the medial axis of the instrument's installed shape. More information on using this tool is available in the Verifying your SAAV Installation guide. Once you have your computer connected to the ShapeArray with the SAARecorder application, open the SAAV Installation Verification tool from the Diagnostics menu and take the following actions that are sometimes referred to as "pumping".

WARNING: If you are installing a ShapeArray in Low Power Mode for use with certain low power data loggers, then you will need to be using an SAAFPU interface with at least revision R.4B or an 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 from the computer without closing the window or the instrument could be left in regular power mode.

Once the SAAV is resting on the bottom of the borehole and you are connected to it with SAARecorder, enter the casing's inner diameter into the Casing Inner Diameter textbox. 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, most of the angles reported by the SAAV Installation Verification tool will be 0° except the last few segments. 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 7: An example of the point graph with the SAAV in the lifted position while pumping

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. Care should be taken to avoid impacts on the side of 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 and wait for the dot graph to settle and finish updating. Press the Capture Compression button. 

When first clicked, the Capture Compression button will prompt you to select a folder and filename into which compression data for the installation will be saved. 

Figure 8: Click Capture Compression button and select a location and filename for the compression data

Compression data will be saved to a plaintext, comma-delimited text file with a .DAT extension with the following naming scheme by default.

compressData_[serial_number]_[YYYY]_[MM]_[DD]_[HH]_[MM]_[SS].dat

Subsequent clicks on the Capture Compression button will append new readings to the selected file and will update a table of readings.

Figure 9. An example of the point graph with the SAAV in the dropped and compressed position while pumping

The SAAV should be lifted, dropped, and compressed repeatedly in this manner until three sequential readings of Compression listed in the table change by less than 1 mm. This should take approximately 10 to 15 lift and drops (pumps). When three sequential compression readings with less than 1 mm of change are recorded, a Green Light indicator will appear.

When the Green Light indicator appears, click on the Create Report and Close button. This will generate a PDF report of the compression results with all of the values captured in the table in the window, as well as as a graph of those results.

WARNING: The SAAV Installation Verification tool has changed several times since the release of the SAAV. If your version of the software presents a different interface, then Measurand recommends updating to the latest release of the software. These older versions of the utility may still be used; however, the only value of interest for verifying the installation is the Compression value. The SAAV should be pumped and compressed until three consecutive readings of Compression change by less than 1 mm.

Step 9 - Find the Azimuth Offset from the X-Mark

The SAA X-Mark Protractor consists of two pieces: a square protractor with directional arrows and a clear plastic disk with an X-Line marked on it. 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 10: 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.

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 11: The clear disk aligned with the X-Lines on the ShapeArray and the square protractor

WARNING: Be careful. Over-tightening the set screws will strip the threads in the PVC.

Using the included PEX cutter, cut away any excess PEX tubing. 

Figure 12: Cutting away excess PEX tubing