Summary

The Snake River sensors are composed of two aluminum strips, applied to the outside of the plastic tanks, and a signal module attached between the foil strips.  There were some installation caveats that required clarification.  The gray water tank was simple and straightforward and even looked like the drawing in the manual.  The fresh water tubes and the toilet holding tank were exceptions.

Toilet Tank - Short and Wide

The toilet tank is very shallow, 4.75".  I knew this would be pushing the limit for any level sensing system.  This system should perform at least as well as any since it senses the mass of fluid in the tank not necessarily its depth.  Therefore it is relatively unaffected by the vehicle being off-level.  The manual says that if the tank is less than 8" deep additional tape should be added to the width of the foil panels to achieve at least fifteen square inches of area for each foil "patch."  The overall height of the tank is 4.75".  Allowing for .5" space at top and bottom of the tank, the height of the foil would be 3.75".  This means the foil patch must be at least 4" wide.  The foil tape in the kit is 2" wide.  Allowing an overlap of .5", minimum of three pieces of tape were required, yielding a 5" width and 18.75 square inches.  Snake River support suggested adding a fourth to get the area over 20 square inches.

( Click to enlarge )

Fresh Water Tank - Tall and Narrow

The fresh water cylinders offered the opposite problem.  The maximum area for the foil patch is 40 square inches, so there was some question about the width of the tape that would allow maximum length.  Snake River suggested cutting the tape to 3/4" wide and a length of 26".  Another caveat about foil sensor placement is to avoid installing near metal.  I did clarify that meant both direct contact and proximity.  Direct contact seemed obvious.  The sensor module that attaches to the foil strips is an oscillator that emits a signal from one foil and senses it from the other.  Touching the foil with metal would eliminate the signal.  Placing metal near it will weaken the signal.  Defining "near" became the issue, and a minimum of one inch was the distance.  So, the final placement of horizontal bracing was designed to manage this distance.  Stand-offs, or saddles, were designed to prevent the mounting straps from contacting the foil strips.

The photos below show some of the saddles and the tank prior to installation.  The sensors were applied directly to the tank surface, which is green.  The entire sensor assembly is covered with a coating of 3M #77 Spray Adhesive, to serve as a sealant.

Saddles
Cylinder/Sensors

( Click to enlarge )