he system works as intended, and was demonstrated very successfully on July 27th.  There is, however, room for improvement.

Accuracy is currently at about 1%.  Since ESI specifies 1% accuracy in their Flo.Point devices, calibration must be performed at a greater degree of accuracy.  It is believed that the replacement of the PVC tube with a glass one, and the removal of the sight glass arrangement will accomplish this accuracy with no other changes to the system.  The amount of time required to set the interface to a specified level will also decrease drastically.

The probes are susceptible to coating by the oil; the higher the viscosity, the greater this effect will be.  As a workaround, calibration should be carried out in the downward direction; that is: from 100% water to 100% oil.  Sufficient rest time before beginning the process will clear the probes of residual oil, and if the direction of movement of the interface is monotonic, coating will not occur.  The effect can also be mitigated by increasing the distance between probes, or coating them with a hydrophilic substance.

The Flo.Point devices are capable of operating with fluids of varying salinity.  The calibration device should also have this facility.  Expansion of the lookup table to a 3-dimensional array with salinity as the extra parameter will achieve this.  The user would be required to know the salinity of the fluid and input it at the beginning of calibration.

A fter implementing some or all of these few changes, ESI will have a much improved system for calibrating Flo.Point devices.