Frequently Asked Questions

What do I do if I rocks or cobbles prevent my making a 22”-23” pilot hole?

If this happens, it is still possible to obtain usable data in such cases. If the coarse fragments in the soil or bedrock prevent making pilot holes to the desired depth ( 22" pilot holes for 20" films), they should be installed to the maximum depth possible. After installation, a mark should be placed at the level of the soil surface on the face of the IRIS film using a permanent marker. Reduction within the zone of interest can still be documented.  

What is the shelf life of IRIS films?

When stored under dry conditions at normal (room) temperatures, IRIS films have a very long shelf life (years) and may be stored for extended periods with no adverse effects to their utility. 

How many delivery tubes do I need?

The number of delivery tubes needed should equal the number of films you wish to deploy in a single day. Delivery tubes are completely reusable. That is one of the advantages of the IRIS film system. However, to avoid scratching the films and for optimal functionality, the tubes should be cleaned between uses. A brush for cleaning the tubes is included with every kit, and tubes are easily cleaned with a light scrubbing using tap water. After cleaning and rinsing, tubes should air dry before loading additional films. What this means is that you should have enough delivery tubes to deploy the films scheduled for a given day. At the end of the day, you can clean and rinse the tubes and allow them to dry overnight and then reload them with IRIS films for the next day's deployment.  NOTE: We have found that cleaning  delivery tubes is easier when using a long flat  plastic basin such that used for storing wrapping paper.  These are  inexpensive and widely available online (https://www.containerstore.com/s/iris-clear-gift-wrap-box/d?q=Clear%20Gift%20Wrap%20Box&productId=10023588

https://www.walmart.com/ip/IRIS-30-Inch-Wrapping-Paper-Storage-Box-Clear/33154123  )

Do I need to use capsule covers?

Capsule covers help to maintain the circular geometry of the top of the films extending above the soil surface. While this is helpful, it is not absolutely essential. Other devices such as O-rings and rubber bands have also been successfully used for the same purpose.

How long can I store films already loaded into tubes?

IRIS films should be loaded into delivery tubes on the day on which they are to be deployed. There can be some “memory” in the PVC film so it is inadvisable to store films loaded within delivery tubes for longer periods of time. Also the “memory” is more noticeable when the loaded films are exposed to high temperatures (95F) for several hours. Once films have been loaded into delivery tubes, they should not be stored in hot places (such as closed automobiles) or left out in direct sunlight for extended periods. 

What if the soil contains fluid sands and the pilot hole fills/collapses?

Occasionally, fluid sands may collapse in the pilot hole and interfere with deployment of the films. When this occurs, an extra delivery tube can be used to remove the collapsing fluid materials by inserting the tube into the pilot hole to the maximum depth possible. A #4 stopper (included with all starter kits) is then inserted into the top of the delivery tube and the delivery tube is extracted quickly which also removes fluid sands from the pilot hole. If necessary, this step can be repeated. Immediately afterward, a film within a delivery tube can usually be deployed as usual - see Video https://youtu.be/NZt9s83J_S0