Changes

 

[[File:Double ring.jpg|thumb|Schematic diagram of double ring infiltrometer illustrating the infiltration of water both vertically, and laterally particularly from the outer ring.]]

[[File:Double ring.jpg|thumb|Schematic diagram of double ring infiltrometer illustrating the infiltration of water both vertically, and laterally particularly from the outer ring.]]

[[File:Bill's double ring.jpg|thumb|Double ring infiltrometer in use]]

[[File:Bill's double ring.jpg|thumb|Double ring infiltrometer in use]]

===Packing list===

===Packing list===

• Small ring (28 – 32 cm)

* Small ring (28 – 32 cm)

• Large ring (53 – 57 cm)

* Large ring (53 – 57 cm)

• Sledge hammer for driving rings into ground

* Sledge hammer for driving rings into ground

• Wooden block to distribute force when driving rings into ground

* Wooden block to distribute force when driving rings into ground

• Level  

* Level  

• Two metal rulers with clips to secure

* Two metal rulers with clips or tape to secure

• Container for water

* Container for water (will water need transporting to site? take more than you think you'll need)

• Screwdriver or similar implement to dislodge rocks

* Screwdriver or similar implement to dislodge rocks

===Installation===

===Installation===

# Choose or create clear, level ground at the desired test location.  

# Choose or create clear, level ground at the desired test location.  

2. Work with minimal disturbance to the soil within the test area.   

# Work with minimal disturbance to the soil within the test area.   

3. Place the wooden block across the ring and use the sledge hammer to drive the ring into the ground by ≥ 5 cm.  

# Place the wooden block across the ring and use the sledge hammer to drive the ring into the ground by ≥ 5 cm.  

4. Check that the ring is level in all directions and correct as necessary.  

# Check that the ring is level in all directions and correct as necessary.  

5. Repeat with the second ring (note that the order may vary if the rings are of differing heights.

# Repeat with the second ring (note that the order may vary if the rings are of differing heights.

6. Both rings should be firm into the ground.  

# Both rings should be firm into the ground.  

7. Secure the metal rulers to the inside of the rings.  

# Secure the metal rulers to the inside of the rings.  

Measurements  

===Measurements===

1. To begin measurements gently pour 5 – 10 cm of water into both the inner and outer rings.  

# To begin measurements gently pour 5 – 10 cm of water into both the inner and outer rings.  

2. Measurement of the water depth should be made every 15 minutes for the first hour, 30 minutes in the second hour and then hourly up to 6 hours.  

# Measurement of the water depth should be made every 15 minutes for the first hour, 30 minutes in the second hour and then hourly up to 6 hours.  

3. The rings should be covered to reduce evaporation, particularly in hot weather and when the soil is clayey and infiltration is slow.

# The rings should be covered to reduce evaporation, particularly in hot weather and when the soil is clayey and infiltration is slow.

 

===The Solver add-in===

===The Solver add-in===

To use the calculation spreadsheet, an additional add-in must be enabled in your Excel program.  

To use the calculation spreadsheet, an additional add-in must be enabled in your Excel program.  

#Go to ‘File’ in you menu toolbar and select ‘Options’ from the menu,

# Go to ‘File’ in your menu toolbar and select ‘Options’ from the menu,

#Choose ‘Add-ins’ and then at the bottom of the window, for ‘Manage Add-ins’, select ‘Go’.  

# Choose ‘Add-ins’ and then at the bottom of the window, for ‘Manage Add-ins’, select ‘Go’.  

#Check the box for the ‘Solver’ add-in and then ‘OK’.  

# Check the box for the ‘Solver’ add-in and then ‘OK’.  

#Your new Solver add-in appears on the right end of the ‘Data’ toolbar in the main Excel window. It is useful for solving all kinds of iterative equations.  

# Your new Solver add-in appears on the right end of the ‘Data’ toolbar in the main Excel window. It is useful for solving all kinds of iterative equations.

 

===Performing calculations===

===Performing calculations===

#Save a new copy of your spreadsheet.  

#Save a new copy of your spreadsheet.  

##‘Solve’!

##‘Solve’!

##The solver produces the optimized S and A values to match the model to the field data.  

##The solver produces the optimized S and A values to match the model to the field data.  

##The saturated hydraulic conductivity (K) is approximated by dividing A by 2/3, where A is the slope of the linear part of the graph. i.e when infiltration rate has stabilized.

##The saturated hydraulic conductivity (K) is approximated by dividing A by 2/3, where A is the slope of the linear part of the graph. i.e when infiltration rate has stabilized.

 

==To review==

==External references==

https://www.astm.org/Standards/D3385.htm

* https://www.astm.org/Standards/D3385.htm an alternative method which uses Mariotte tubes to maintain a constant water level during testing.