Appendix B: Existing OPW/EECO 
Equipment  
Model 924A Probes 
CAUTION:  CANNOT  BE  MULTI-DROPPED  ON 
VSMART. 
The  Model  924A  Probe  utilizes  magnetostrictive 
technology to derive accurate product and water levels. It 
is  primarily  used  in  underground  storage  tanks  for 
inventory and leak detection. Two floats can be fitted to 
the probe shaft; the product float sits on top of the product 
and the water float (optional) sinks through the product 
and sits on top of the water at the bottom of the tank. 
Five temperature  sensors  reside  in  the  probe shaft  for 
measuring product temperature at different levels in the 
tank. They are located at positions of approximately 20%, 
40%,  60% and  80% of  the  tank’s  volume. The  sensors 
feed the data of the temperature of the fuel to the console. 
The  console  software  is  then  able  to  make  the 
calculations to produce a net corrected product volume.