How will coating affect the measurement?
If coating forms on the probe the measured signal will be weaker. If the media itself has a high dielectric constant some coating is not much concern but if it is a low DC media coating can be a problem. If a twin probe or a coaxial probe is used the coating can cause bridging between the two leads and this will create false echoes that can lead the transmitter to interpret a bridge as the actual level. Single lead is recommended in coating applications. Coating can cause an accuracy influence. Maximum error due to coating is 1-10% depending on probe type, dielectric constant, coating thickness and coating height above product surface.
