Guided Wave Radar Pulse Timing for End-of-Probe Reflection Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
End-of-probe reflections in guided wave radar level gauges interfere with level measurements, particularly in large tanks, causing disturbances in pulse repetition frequencies, which existing technologies have not adequately addressed.
Innovation Solution
A guided wave radar level gauge with a control circuitry that adjusts the pulse repetition frequency based on the probe length and dielectric properties to minimize the influence of double and triple end-of-probe reflections, ensuring these reflections do not interfere with the measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a wave absorption device is arranged at the end of the probe to reduce reflections, then spurious echoes are reduced to a limited degree, but remaining reflections still influence level measurement under specific circumstances
Solution Approach 1:
The pulse repetition frequency is made dynamically adjustable based on the probe length. The control circuitry automatically sets the pulse repetition frequency to ensure that the round-trip time for electromagnetic signals traveling to the end of the probe and back is less than the pulse repetition period, preventing double and triple reflections from interfering with level measurements.
Solution Approach 2:
The pulse repetition frequency parameter is changed and optimized according to the probe length. By adjusting this parameter, the system ensures that the time for double and triple reflections (which travel longer paths) is less than the pulse repetition period, thereby eliminating interference from these reflections.
2Productivity
If the pulse repetition frequency is increased to improve measurement speed, then productivity is improved, but double and triple end-of-probe reflections interfere with measurements in large tanks
Solution Approach 1:
The control circuitry automatically determines the probe length and uses this information to calculate and set the appropriate pulse repetition frequency. This feedback mechanism ensures that the pulse repetition frequency is always optimized for the current probe configuration, preventing reflection interference while maintaining measurement speed.
Solution Approach 2:
The system performs preliminary determination of the probe length and calculates the optimal pulse repetition frequency before actual level measurements begin. This preliminary setup ensures that subsequent measurements are free from reflection interference without requiring trial and error adjustments.
3Adaptability or versatility
If the probe length is increased to measure larger tanks, then adaptability is improved, but double and triple end-of-probe reflections become more significant and interfere with measurements
Solution Approach 1:
The pulse repetition frequency is dynamically adapted to the probe length. As the probe length increases for larger tanks, the control circuitry automatically adjusts the pulse repetition frequency to maintain the condition that double and triple reflection times are less than the pulse repetition period, thereby maintaining measurement accuracy across all tank sizes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution improves measurement accuracy by eliminating the interference from end-of-probe reflections, allowing the gauge to function effectively in tanks of varying sizes by dynamically setting the pulse repetition frequency.
Implementation Method 1
The transceiver (17) is configured to generate and transmit a signal in the form of a pulse train
Implementation Method 2
The transmitted electromagnetic signals are reflected at the surface of the product
Implementation Method 3
the distance to the surface of the product is generally determined based on the time between transmission of an electromagnetic signal and reception of the reflection thereof
Data Source
Figure 1~2
Figure 3~4B
Figure 5
AI summary
A guided wave radar level gauge (1) for determining a fill level of a product contained in a tank comprising: a transceiver (17) configured to provide a transmit signal, Tx-signal, in the form of a pulse train, having a controllable pulse repetition frequency fTx, and to receive a reflected signal resulting from a reflection of the transmit signal at a surface of the product; a probe (11) connected to the transceiver and configured to propagate the Tx-signal towards the surface and to return the reflected signal to the transceiver, the probe having a known length; and control circuitry (19) configured to determine the fill level based on the received reflected signal, wherein the control circuitry is further configured to set the pulse repetition frequency based on the length of the probe.