A deposition process for coating a substrate with an ultrasonically generated aerosol spray, is described. A locking mechanism is also provided for securing the latch from unauthorized opening, the locking mechanism having a locking element which holds the actuator against movement and prevents the retraction of the pawl. The invention has been created to address particular problems in the design of digital sampling oscilloscopes that require more bandwidth than that which is easily achievable through traditionally analog techniques. A learning correction coefficient relating to a change in characteristics of the intake air flow rate sensor can be calculated using the correlation parameter.