Patent ID: 8857257

Claim:
A method of operating a vibrating element apparatus which, in use, is subject to contact and removal of contact with a fluid, said method comprising steps of: causing a vibrating element to vibrate at an operating frequency during normal operation; and observing a change in said operating frequency in response to said vibrating element changing from being dry to wet or from being wet to dry; indicating that the vibrating element is wet or dry based on the change in said operating frequency; storing over time measurements of said operating frequency measured during normal operation to capture changes in said measurements, all of the stored measurements being taken while the vibrating element is dry or, alternatively, while the vibrating element is wet; delaying a measurement of said operating frequency for a time period following a change of said vibrating element from being wet to being dry, or from being dry to being wet; monitoring changes in said stored measurements; and generating an alert if a stored measurement differs from an earlier stored measurement by a predetermined amount; wherein the alert signifies that the indicating step falsely indicates, or will falsely indicate, that the vibrating element is wet or dry.