Question 1: What is the reason that the laser tube cannot start up normally after it has been unused for more than one week? What should be done in this case?
Answer:
If the laser tube has been unused for more than one week, it may not be able to perform pre-ionization when it starts to use. In this case, the laser control circuit will detect a high backward reflection voltage, which will result in ‘SWR error’ & ‘Laser OK / Fault’, and cause the laser tube to fail to start normally.
Therefore, in order to avoid from triggering SWR errors, it is recommended to adjust the duty cycle of the modulation signal ≤3% and the frequency < 25KHz when it starts to run.
If an SWR error has occurred, the user can continue to apply the modulation signal to the laser tube, and the control circuit board inside the laser tube will send auxiliary ionization pulses to assist the laser in ionization.
Steps for startup correctly:
1. Switch on the laser tube and wait for one minute;
2. Adjust the duty cycle of the modulation signal ≤ 3%, the frequency < 25KHz, then pre-warm-up for 5 minutes;
3. Gradually increase the power to vary from 0-100%, it takes 2 minutes;
4. Start doing work
Note: In the case that the laser device is frequently used, its pre-ionization time is 30s only, which is determined by the internal program of the laser tube. It will automatically execute after each time that power outage and power on again.
Question 2: Laser tube need a certain pre-ionization time when it starts working, is it possible to speed up the pre-ionization time by intentionally sending a modulating signal?
Answer:
No, it cannot, unless by modifying the program. The pre-ionization of the laser tube is done by the internal pre-ionization circuit. The pre-ionization circuitry starts to work as soon as the laser tube is switch on. An artificial modulation signal cannot help the laser tube to complete the pre-ionization state.
Question 3: Is it necessary to perform regular cleaning for the laser's fan and heat sink of the tube?
Answer:
Yes, it is. Due to the dust in the environment adhering to the laser fan and heat sink, it will greatly affect the cooling effect of the laser, which will lead to the heat of the laser tube cannot be effectively conducted, further causing irreparable failure of the laser.
Question 4: What could happen when the laser tube is protected from overheat and how should it be handled?
Answer:
If the laser tube gets overheat protection, it will stop working. When such a situation occurs, the user needs to do the following:
(1) Switch off the power supply of the laser.
(2) Check the chiller, whether the working condition is normal.
(3) Check the fan, whether it works normally
(4) Whether the fan and heat sink need to be cleaned.
(5) Whether the peripheral heat dissipation space for the air-cooling laser tube is sufficient.
(6) After eliminating the above possible failures, the user should wait for the temperature of the laser tube to be cooled down in the required range.
(7) Switching on the laser tube.
Question 5: After the laser tube is power on, why can't the control terminal PIN of the laser be in a suspended or high resistance state?
Answer:
When the laser tube is switch on, it will enter the working state. If the control PIN of the laser tube is in a suspended or high resistance state, then the electrical level on the PIN will stand in an unknown state, which may lead to the following situations:
1. A large number of noise signals on the PIN which get the laser tube damaged.
2. If there is an unknown high level on the PIN, the laser tube may emit beam accidentally, which could directly threatens the personal safety.
Question 6: Can PIN 7 to be used as the signal modulation terminal to modulate the laser beam output?
Answer:
No. It cannot. PIN 7 is the control enable terminal of the laser tube. Too high switching frequency will cause laser failure. The switching frequency of signal for PIN 7 should be < 200Hz.
Question 7: What should be paid attention during the storage and transport for the laser tubes?
Answer:
1. The laser must be stored and transported in the process to ensure that the cooling water inside the laser is completely blown dry, and it is recommended that the laser be blown dry with dry nitrogen gas with a purity of 99.95%, otherwise the cooling water inside the laser will cause irreparable damage to the internal structure of the laser tube.
2. The laser output window must be sealed during storage and transport to protect from dust or pollution.
3. It should be held and placed very carefully to avoid from getting accidental impact.
4. Ensure that the water pipe keep unstressed to avoid from deformation.
Question 8: What are the requirements for the laser operating environment?
Answer:
1. The ambient temperature needs to kept at 5 ℃~40 ℃. Air conditioners must be used when necessary.
2. Environmental cleanliness. If the laser tube under high dust level, without external dust protection equipment, It will cause the output window mirror burnt.
3. Ambient humidity. Requires has no condensation
4. The ambient PH remains neutral.
Question 9. If the laser output window mirror is polluted, how to deal with it? And whether can wipe it with cotton swabs?
Answer:
Wiping with cotton swabs will damage the output window mirror. If the front mirror is only attached a small number of particles, and the coating of the mirror has not burnt, then try to use nitrogen with a purity of 99.95% to wipe the mirror. It is do necessary to unplug the power supply before doing it.
Question 10: If the size of the beam spot is already known, how to choose the size of the lens in the optical path?
Answer:
The size of the lens for the external beam path should generally be selected as twice the actual spot size.
Question 11: What is the reason that the output power at the laser outlet is sufficient, but the power at the terminal of processing is very low?
Answer:
This situation is generally caused by the presence of high energy loss in the external optical path of the laser.
Users should check the following points:
Whether the size of the lenses of the external beam path and the size of the aperture of the beam passage is large enough.
1. Whether the quality of the lenses of the external beam path is qualified, and the loss of a single lens cannot exceed 3%
2. Whether the lenses of the external light path are polluted or damaged.
3. Whether the external beam path has been correctly aligned.
Question 12: What should be done if the power of the laser tube is low or unstable during working?
Answer:
The user needs firstly check the following items:
1. Measure the DC power supply voltage of the laser with a multimeter to see whether it is normal.
2. Use an oscilloscope to measure the laser DC power supply output, to observe whether there are large fluctuations.
3. Use an oscilloscope to measure whether the control signal to the laser is normal.
4. Measure whether the chiller works normally and the flow rate meets the requirements as well.
5. Check whether the fan of the air-cooled laser tube and the heat sink are in a normal state.
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