Spurious Reflection
Unwanted radar or ultrasonic echoes originating from the internal walls of a mounting nozzle or flange can obscure the true signal from the product surface in a storage vessel. This nozzle clutter occurs when the transmitted energy scatters off the welding seams or step changes in the nozzle diameter. The resulting false signals appear at close range, making it difficult to measure high liquid levels accurately.
Minimizing these reflections is critical for maintaining high measurement precision.
Echo Suppression
Digital filtering techniques are applied to map and subtract the static reflections from the active signal. During setup, the software records the nozzle clutter signature while the tank is empty. This baseline scan allows the transmitter to ignore these stationary echoes during normal operation.
Installation Influence
The height and diameter of the mounting nozzle are critical factors that determine the severity of the unwanted reflections. A tall, narrow nozzle produces intense nozzle clutter that can completely mask the return echo from the liquid surface. To prevent this, standard installation guidelines recommend keeping the nozzle as short and wide as possible.
This positioning ensures that the sensor beam avoids striking the nozzle walls.
Calibration Adjustment
Field technicians use specialized software to manually adjust the echo threshold curve around the mounting flange area. This manual tuning ensures that the nozzle clutter does not trigger false high-level alarms during rapid filling cycles. By checking this adjustment under different operating temperatures, the sensor is prevented from losing track of the true liquid level as the internal environment changes.
The resulting signal clarity ensures high reliability in process monitoring applications.
