With any probe, naturally occurring static friction (or “stiction”) between the float and the probe shaft can cause the float to remain in place when the product level drops and even when it rises. This can affect the accuracy of both level readings and leak detection.
Probes can experience stiction to varying degrees. If the probe isn’t installed plumb or the tank is tilted, this can cause the probe to sit at a slight angle. This angle can create stiction between the probe and the float as the float isn’t free to move cleanly up and down the probe shaft. You can identify if stiction is occurring on any probe by taking a look at the level and volume data. If you see a constant tank level followed by a brief period of rapid level increase or decrease, the probe may be experiencing stiction. Additionally, if you encounter trouble with leak testing this may also indicate a stiction problem.
What Can You Do About It?
To help avoid stiction and the troubles it can cause, it’s important to make sure your probes are always installed plumb. This ensures the probe isn’t sitting at an angle and the floats can move freely up and down the shaft. This simple installation best practice will greatly reduce the likelihood of stiction events occuring. Cleaning the probes and the floats can also help reduce the regularity and severity of stiction events.
Another way to avoid stiction with your probe solution, is to choose the new INCON® brand digital probes from Franklin Fueling Systems. These probes were specially designed to combat this common problem. The probe features a unique and innovative vibration motor mounted inside the probe head. Approximately every 5 minutes, the vibration motor automatically pulses. This frees the floats from any static friction with the probe shaft and mitigates the negative effects stiction can have on level readings or leak detection accuracy. The probes also feature a bottom-mount design, making them simple and easy to install.
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