In addition to the same electric shock, burn and fire as manual arc welding, argon arc welding also has high frequency electromagnetic field, electrode radiation and arc light damage, welding smoke and toxic gas which is much stronger than manual arc welding.

The harm degree of argon arc welding is larger than that of electrode arc welding, but it is not so big that people are afraid of it. The infrared radiation is about 1 ~ 1.5 times of that of ordinary electrode arc welding, and the ultraviolet radiation generated by argon arc welding is about 5 ~ 20 times of that of electrode arc welding.Chief among them are high-frequency electricity and ozone.

So we should do a good job of protection in the welding process, choose the electrode material, as far as possible to choose less radioactive cerium tungsten.When grinding electrodes, wear masks and gloves, and wash hands after work to minimize the harm.

1. Generation and harm of high frequency electromagnetic field

   In GTAW and plasma arc welding, high frequency oscillators are often used to stimulate the arc initiation, and some AC argon arc welders also use high frequency oscillators to stabilize the arc.High-frequency oscillators commonly used for welding have frequencies of 200 -- 500 kilo-cycles, voltages of 2500 -- 3500 volts, hf current intensity of 3 -- 7 mA, and electric field intensity of about 140 -- 190 volts/m.Welders exposed to high frequency electromagnetic field for a long time cancause plant nervous dysfunction and neurasthenia.Symptoms include general malaise, dizziness, dreaminess, headache, memory loss, fatigue, loss of appetite, insomnia and low blood pressure.

   The reference health standard for hf electromagnetic fields specifies an allowable radiation level of 20 volts/m for 8 hours of exposure.According to the measurement, the high frequency electromagnetic field intensity of all parts of the welder during manual ARGON tungsten arc welding exceeds the standard, and the intensity of the hand is the largest, which exceeds the health standard more than 5 times.If only the use of high frequency oscillator arc starting, because of the short time, the impact is small, but long-term contact is also harmful, must use effective protection measures.

2. Protective measures against high-frequency electromagnetic fields

   (1)The arc starting and arc stabilizing measures of argon arc welding try to use transistor pulse device, not high frequency oscillation device, or only used to start the arc, immediately cut off the high frequency power supply after the arc ignition.

   (2) Reduce the oscillation frequency, change the parameters of capacitor and inductance, reduce the oscillation frequency to 30 kilo-cycles, reduce the impact on human body.

   (3) Shielded cable and wire, made of fine copper flexible wire, set on the cable hose outside (including welding torch and wire to the welding machine), and the ground.

   (4) Because of the high voltage of the high-frequency oscillation circuit, good and reliable insulation should be provided.