1. Access Tube Installation for Diviner 2000 & EnviroSCAN
Sentek Technologies
Access Tube Installation
for Diviner 2000 & EnviroSCAN

2. Installation Types Standard Installation Installation in Heavy Clay
Installation in Dry or Loose Sand
Slurry Installation – Stony Soils
Removing Access Tubes

3. A. Standard Installation Technique
Use installation tripod
Use 47.0 mm auger to auger through the access tube
Suitable for most soil types and should be used where possible

4. Step 1. Assembling the Tripod
Attach the base plate to base of tripod
Centre tripod over installation site
Spread tripod legs until base plate touches the ground
Secure tripod in position by driving tripod pins through the tripod legs into the soil

5. Step 1. Assembling the Tripod
Insert sledge hammer handle into the tripod cylinder and straighten tripod by moving tripod cylinder into vertical position.
Move the tripod until bubble in spirit level is located in centre of the level window
Tighten wing nuts of the legs

6. Step 2. Installing the Access Tube
Turn metal cutting edge onto side & shave a layer of PVC from lip of access tube
Insert cutting edge onto the end of the access tube by tapping on the head of the sledge hammer or other solid object, be careful not to damage the cutting edge

7. Step 2. Installing the Access Tube
Select the 47 mm regular auger head
Select the required extension rods and screw auger head and T-handle to the extension rods.

8. Step 2. Installing the Access Tube
Feed the assembled auger through the inside of the access tube until the auger head protrudes 20 cm through the tube
Place a mark on the auger extension with a marker pen to show the required augering depth.

9. Step 2. Installing the Access Tube
Insert the access tube with fitted cutting edge into tripod guide tube
IMPORTANT: ensure metal ‘tooth’ inside tripod is not engaged while hammering tube
Select heavy duty dolley and insert into top of access tube
Use sledgehammer to tap the dolly until access tube is embedded 5-10 cm (2-4 in) into the soil

10. Step 2. Installing the Access Tube
Place auger inside tripod tube guide and turn auger to remove soil from inside access tube
Continue to auger ahead of access tube by approximately 20 cm (as marker on auger extension earlier)
If access tube spins while augering engage metal “tooth” on tripod

11. Step 2. Installing the Access Tube
Take the auger out of the tube and empty the soil using the small auger cleaning tool
DO NOT empty augered soil onto the surrounding site – it may change the infiltration rate of rainfall & irrigation.

12. Step 2. Installing the Access Tube
Select Heavy duty dolley re-insert into top of access tube
Take the sledge hammer and hit the dolly to drive the access tube further into the pre-drilled hole.
When you reach the bottom and hammering becomes noticeably more difficult, remove the dolley
Alternate between augering & hammering until the dolley nearly touches the top of the tripod.

13. Step 2. Installing the Access Tube
Insert nylon dolley into the access tube & continue hammering & augering until the mark on the dolley is level with the top of the tripod.
The access tube will now be 40mm out of the ground

14. Step 2. Installing the Access Tube
Remove the tripod by inserting the tommy bars into the holes of the tripod pins and pulling them upwards with a twisting motion.
Carefully lift tripod straight upward & off access tube
Ensure that access tube does not move & that there are no visible air gaps.

15. Step 3. Cleaning the Access Tube
Detach auger head and attach the brush cleaning tool
Plunge brush tool up and down length of the access tube using rotating motion to remove any loose soil sticking to the inside walls

16. Step 3. Cleaning the Access Tube
Assemble rag cleaning tool.
Attach clean cotton cloth through eyelet of rag cleaning tool.
Soak cloth in methylated spirits
Insert rag cleaning tool and swipe up and down inside of access tube
Change cotton cloths as required and continue until access tube is clean & dry

17. Step 4. Installing Bottom Stopper Bung
Ensure access tube is clean
Partially insert expandable bung into access tube and hold so that 75% of top rubber ring is within access tube
Tighten wing nut to point where there is sufficient friction to prevent bung turning when wing-nut tightened

18. Step 4. Installing Bottom Stopper Bung
Attach Expandable bung tightening tool to the auger extension rod and tighten with tommy bars
Place Expandable bung tightening tool over wing nut and slowly push bung into access tube
Slowly turn T-handle until cannot tighten any further
Twist the tool clockwise slightly and pull upwards. This will release the spring on the tool from the wing nut and enable you to pull the tool out of the access tube.

19. Step 5. Installing the Top Cap
Ensure access tube is protruding 40mm out of ground
Ensure the length of access tube protruding from the soil is clean inside & out
Apply three rings of silicon around the outside of the access tube about 1 cm (0.4 inch) below the top of the rim.

20. Step 5. Installing the Top Cap
Unscrew top cap from top cap assembly base
Push top cap base onto top of access tube with a slight rotating motion until the lip of the top cap sits neatly on the rim of the access tube.
Make sure cable and cable gland faces the direction of the logger or DTU, or in the case of a Diviner, the red plug should point to the right of the person taking readings.

21. Step 5. Installing the Top Cap
Wipe off excess silicon from inside the access tube
Screw the cap back onto the top cap housing.
Make sure not to spin the top cap housing until silicon is dry

22. B. Installing in Heavy Clay Soils
This method is specifically for heavy clays where the standard installation method is not possible
Use the 53.0 mm auger for moist to wet clay
Use the 56.0 mm auger for dry clay

23. Installing the Tube
Ensure the tripod is set up correctly and centred over the installation site
Select the 53.0 mm clay auger for moist to wet clay or the 56.0 mm clay auger for dry clay.
Fit the stabilization poly guide over the extension rods and attach the T-handle.

24. Installing the Tube
Insert the assembled auger into the tripod ensuring the centralization poly guide is fitted to the top of the tripod cylinder.
Auger to the required depth of installation. Regularly clean the auger head away from the installation site.

25. Installing the Tube Fit cutting edge onto the access tube
Insert Heavy duty dolley into tube and hammer in access tube until dolly nearly touches top of tripod

26. NOTE: This places the first sensor 10 cm below the surface.
Installing the Tube
Insert nylon dolley and continue hammering until the mark on the dolley is level with the top of the tripod.
NOTE: This places the first sensor 10 cm below the surface.

27. C. Installing in Dry & Loose Sand
Use the access tube spiral cleaning tool as the augering device

28. D. Stony Soils – Slurry Installation
Slurry Installation methods are recommended for:
Soils high in stone and gravel
Installations deeper than 2.5 – 3.0 metres

29. Step 1. Glue in Slurry Bottom Stopper
Clean both surfaces with PVC cleaning fluid
Apply PVC glue evenly to both surfaces
Insert slurry bottom stopper into access tube and hold in place until glue sets.
It is recommended to test the seal in a bucket of water (This step can be done before you get into the field)

30. Step 2. Augering the Oversized Hole Manually
Attach the 61 mm auger head and T-handle to extension rods
Auger hole to required depth
You may need to use the tungsten tipped auger or rock breaker if you encounter difficulties

31. Step 2. Augering the Oversized Hole (Mechanically)
If augering is too difficult manually, you may need to use a mechanical flight auger with tungsten tip attached to a drill rig
NOTE: Flight auger must be 61.0 mm in diameter

32. Step 3. Checking the Hole Depth
Insert the access tube with slurry bottom stopper fitted to check the depth level. The top of the access tube should protrude by 40mm.
Cut the tube to length if necessary.

33. Step 4. Making the Slurry Slurry Recipe: 4 parts kaolinite
1 part cement
4-5 parts water

34. Step 4. Making the Slurry
Measure out 4 parts kaolinite and 1 part cement and mix in a plastic container
Slowly add 4-5 parts of water and stir with paint stirrer until no lumps

35. Step 5. Inserting the Access Tube
Pour the slurry into the hole until it fills approximately a third to half the hole
Slowly insert sealed end of access tube through the slurry, allowing air bubbles to escape
Allow slurry to dry for a few hours
Take a spatula or broad knife and remove excess dried slurry from the soil surface
If slurry has settled and formed depression, make up a small quantity of extra slurry and fill gaps, allow to dry, then chip away excess

36. Step 6. Installing the Top Cap
Apply 3 rings of silicon around the outside of the access tube, 1cm below top of the rim
Push top cap base onto top of access tube with a slight rotating motion until the lip of the top cap sits neatly on the rim of the access tube.
Wipe off excess silicon from inside the access tube

37. E. Removing Access Tubes
Unscrew the top cap and remove the probe
Attach T-handle and expandable bung tightening tool to auger extension
Tighten using tommy bars
Insert bung tightening tool into access tube. Click onto expandable bung and turn anti-clockwise until bung loosens, make sure not to unscrew bung tool
Pull upwards and remove bung.

38. E. Removing Access Tubes
Slide diagonal parts of tube extraction tool so that they form a cylinder
Insert tube extraction tool into access tube and tap horizontal bar with small hammer

39. E. Removing Access Tubes
Assemble lifting device and attach to extraction tool
Carefully winch tube upward and out of ground
NOTE: An access tube extraction tool tripod is available from Sentek however some kind of other tripod and winch can be used.