Ultrasonic equipment plays an indispensable role in many fields such as industrial production, medical testing, scientific research experiments, etc. with its unique working principle. However, like any complex electromechanical equipment, ultrasonic equipment will inevitably encounter various faults during long-term operation. Timely and accurate maintenance can not only ensure the normal operation of the equipment, but also provide stable support for work in related fields.
Overview of the working principle of ultrasonic equipment
Ultrasonic equipment is mainly composed of ultrasonic generators, transducers, coupling agents, and various control and display components.
The ultrasonic generator generates a high-frequency electrical signal, which drives the piezoelectric crystal or magnetostrictive material in the transducer to generate mechanical vibrations, thereby emitting ultrasonic waves. Ultrasonic waves propagate in the medium, and reflection, refraction, etc. occur when encountering different medium interfaces. The reflected waves are received by the transducer and converted back into electrical signals. After signal processing and analysis, information about the internal structure, defects or other characteristics of the object being measured can be obtained.
Common fault troubleshooting and repair
1. Ultrasonic generator fault
- Fault phenomenon: no output voltage
Troubleshooting steps: First check the power input line to see if the plug is loose and the fuse is blown. If the fuse is blown, replace it with a fuse of the same specification after finding out the cause. Then check the rectifier circuit, filter capacitor and other components inside the generator, and use a multimeter to measure whether the voltage value is normal.
Repair method: For damaged rectifier diodes, capacitors and other components, components of the same model or similar parameters should be replaced. For example, if the filter capacitor is found to have serious leakage, it can often restore normal output voltage after replacing it with a high-quality capacitor with the same capacity and withstand voltage value.
- Fault phenomenon: unstable output voltage
Troubleshooting steps: Check whether the components in the voltage feedback circuit, such as resistors, capacitors, operational amplifiers, etc., have cold soldering, damage or performance drift. At the same time, monitor the stability of the input power supply to see if there is a large voltage fluctuation.
Repair method: For components with poor soldering, re-solder them firmly; for damaged or poorly performing components, such as operational amplifier imbalance, replace new components and perform appropriate debugging, and adjust the resistance of the feedback resistor to stabilize the output voltage.
2. Transducer failure
- Failure phenomenon: The transducer does not vibrate
Troubleshooting steps: Check the connecting cable between the transducer and the generator to see if there is a break, short circuit or poor contact. Use an insulation resistance meter to measure the insulation resistance of the transducer to determine whether it has leakage. If the insulation resistance is too low, it means that there may be moisture or breakdown problems inside the transducer.
Repair method: For problems with the connecting cable, repair or replace the cable. If the transducer is damp, it can be placed in a drying oven for drying, and the temperature can be controlled in an appropriate range (such as 50-60℃). The time depends on the degree of moisture, generally ranging from several hours to several days. For transducers with internal breakdown, if conditions permit, the damaged piezoelectric element can be replaced or the entire transducer can be replaced directly.
- Failure phenomenon: The transducer vibrates abnormally and makes abnormal sounds.
Troubleshooting steps: Check whether the transducer is installed firmly and whether there is looseness or resonance. Observe whether there is damage or foreign matter attached to the surface of the transducer. Use an oscilloscope to detect the input electrical signal and output vibration signal of the transducer, and compare the waveform during normal operation to check whether there is distortion.
Repair method: If the installation is loose, re-tighten the transducer. If there is foreign matter on the surface, clean it carefully. If there is resonance, adjust the installation position of the transducer or add damping material to eliminate the resonance. If the waveform distortion is caused by abnormal input electrical signal, check the generator fault; if it is caused by the performance degradation of the transducer itself, such as aging of the piezoelectric element, consider replacing the transducer.
3. Display and control component failure
- Failure phenomenon: The display screen is distorted or there is no display
Troubleshooting steps: Check whether the data cable connection of the display screen is reliable and whether it is loose or damaged. Check the power supply circuit of the display screen and measure whether its input voltage is normal. If the power supply is normal, the driver chip or LCD panel of the display itself may be damaged.
Repair method: For the problem of loose data cable, re-plug and connect firmly. If the data cable is damaged, replace the data cable. For power supply circuit failure, repair or replace damaged components, such as voltage regulator chip, filter capacitor, etc. If the display itself is damaged, replace the corresponding display assembly according to the device model.
- Fault phenomenon: Control panel button failure
Troubleshooting steps: Check whether the button is stuck, damaged or in poor contact. Use a multimeter to measure the circuit connection point corresponding to the button, and check whether there is a change in on-off when the button is pressed. If the button is normal, it may be a microprocessor or related chip failure on the control board.
Repair method: For stuck or damaged buttons, clean or replace the button. If the contact is poor, repair the button contact or replace the button switch. If the chip fails, it is necessary to further check the peripheral circuit of the chip. After determining the cause of the failure, replace the faulty chip or reprogram the microprocessor (if it is caused by a program problem).
Testing and verification after maintenance
After completing the maintenance of the ultrasonic equipment, comprehensive testing and verification work must be carried out. First, turn on the equipment and check whether its various parts start up normally and whether there are any abnormal sounds, heat or smoke. Then, use standard test samples or objects with known characteristics to conduct ultrasonic testing experiments, compare the test results before and after the repair, and check whether the performance indicators of the equipment, such as resolution, sensitivity, and measurement accuracy, have returned to normal levels. At the same time, verify the operation of various control functions of the equipment to ensure that the interaction of components such as the control panel and display is normal. Only after rigorous testing and verification can we ensure that the repaired ultrasonic equipment can be put into use stably and reliably.
