Radar level meter sensor failure

Project Overview

1. Overview

As a non-contact level measuring instrument, the radar level meter is used in chemical industry, Electric power, metallurgy, food, pharmaceutical and other fields. However, as its core component, the radar level meter sensor may also malfunction, affecting measurement accuracy and even causing equipment shutdown. This article will discuss the common fault phenomena, cause analysis and solutions of radar level meter sensors, aiming to provide reference for relevant technical personnel and improve the reliability and safety of the equipment.

2. Common sensor fault phenomena

Radar level meter sensor faults usually manifest themselves as the following phenomena:

Measurement value drift: refers to the instability of the measurement value , the fluctuation is large and inconsistent with the actual material level. Inaccurate measurement value: refers to the large deviation between the measurement value and the actual material level, and the error exceeds the allowable range. Measured value jump: refers to the sudden jump of the measured value, obvious fluctuation, and the actual material level cannot be displayed stably. Unable to measure: It means that the sensor cannot receive the echo signal, cannot measure, and displays no signal or error code. Frequent alarms: means that the sensor frequently triggers high and low alarms, causing false alarms and affecting normal production.

In addition to the above common phenomena, other abnormal situations may also occur, which need to be judged and handled according to the specific situation.

3. Analysis of sensor failure causes

There are many causes of radar level meter sensor failures, which can be analyzed from the following aspects:

3.1 Failure of the sensor itself

The radar level meter sensor is a precision component, which may itself fail. The main reasons are as follows:

Transmitting/receiving antenna failure: antenna damage, aging, dust accumulation, etc. Affects signal transmission and reception, resulting in inaccurate or impossible measurement values. Microwave circuit failure: aging of circuit boards, damaged components, etc. will affect signal processing, causing measured values ​​to drift, jump, or fail to measure. Crystal oscillator failure: The instability of the oscillator frequency will affect signal transmission and reception, resulting in inaccurate or drifting measurement values. Power amplifier circuit failure: Power amplifier circuit failure will result in insufficient signal transmission power, affecting the measurement distance, resulting in inability to measure or inaccurate measurement values. Signal processing chip failure: Chip failure can cause signal processing errors, resulting in inaccurate or jumpy measured values.

3.2 Installation issues

Improper installation of sensors can also lead to failures. The main reasons are as follows:

Improper installation location: The sensor is not installed in a good location, such as distance from the medium. Too far or too close will affect signal transmission and reception, resulting in inaccurate or impossible measurement values. Improper antenna angle: Improper antenna angle will lead to unsatisfactory signal reflection and affect measurement accuracy. Inaccurate installation height: Inaccurate installation height will cause measurement value deviation and affect measurement accuracy. Impact of pipe elbows: Installing near elbows or valves will cause abnormal signal reflection and affect measurement accuracy. Impact of media vibration: Installation in vibrationIn a dynamic environment, it will interfere with signal transmission and reception, resulting in inaccurate or impossible measurement values.

3.3 Environmental factors

The working environment of the sensor will also affect its performance. The main reasons are as follows:

Temperature changes: Temperature that is too high or too low will affect the performance of the sensor element, causing the measurement value to drift or be inaccurate. Humidity is too high: Humidity that is too high will cause the internal components of the sensor to become damp, affecting the working performance, resulting in inaccurate or impossible measurement values. Medium properties: The electromagnetic properties, dielectric constant, density and other parameters of the medium will affect signal transmission and reception, resulting in inaccurate or biased measurement values. Changes in medium composition: Changes in medium composition will affect signal reflection, causing measurement values ​​to be inaccurate or jump. Electromagnetic interference: The presence of strong electromagnetic fields around will interfere with signal transmission and reception, resulting in inaccurate or impossible measurement values.

3.4 Circuit connection problems

Sensor circuit connection problems can also cause failures. The main reasons are as follows:

Wiring errors: Wiring errors can cause abnormal signal transmission and affect Measurement accuracy may not be measurable. Poor wiring contact: Poor wiring contact will cause unstable signal transmission, affect measurement accuracy, or cause measurement value jumps. Unstable power supply voltage: Unstable power supply voltage will affect the performance of the sensor, causing measurement values ​​to drift or be inaccurate. Interference signals: Interference signals generated by other equipment or lines will affect the normal operation of the sensor, resulting in inaccurate or impossible measurement values.

4. Sensor troubleshooting methods

Radar level meter sensor troubleshooting methods need to be judged according to the specific situation. Some common handling methods are listed below:

4.1 Check the sensor

First of all, check whether the sensor itself is faulty. You can perform the following operations:

Visual inspection: Check whether the sensor is obviously damaged, dusty, corroded, etc. Test the transmit power: Use special test equipment to check whether the sensor transmit power is normal. Test the receiving signal: Use a test instrument to check whether the sensor receiving signal is normal. Replace the antenna: If the antenna fails, you can replace it with a new one for testing.

4.2 Check the installation

To check whether the sensor installation meets the requirements, you can perform the following operations:

Check the installation position: Make sure the sensor installation position is reasonable and the distance from the medium is appropriate. Check the installation height: Make sure the sensor installation height is accurate and consistent with the level measurement range. Check the antenna angle: adjust the antenna angle so that it is perpendicular to the medium surface to ensure normal signal reflection. Check the installation and fixation: Make sure the sensor is installed firmly to avoid looseness that may cause unstable signals.

4.3 Check environmental factors

To check whether the sensor working environment meets the requirements, you can perform the following operations:

Check the temperature: Make sure the sensor working environment temperature is within the allowable range , and take cooling measures. Check the humidity: Make sure the humidity of the sensor working environment is within the allowable range, and take drying measures. Check the medium characteristics: Understand the electromagnetic characteristics, dielectric constant, density and other parameters of the medium, adjust the sensor parameters or replace the sensor type. Check electromagnetic interference: Reduce surrounding electromagnetic interference, such as shielding the source of interference or adjusting the location of the equipment.

4.4 Check the circuit connection

To check whether the sensor circuit connection is normal, you can perform the following operations:

Check the wiring: Check whether the sensor wiring is correct and whether there is an open circuit or Short circuit or poor contact.