To confirm that a weld has been made to specification:

For arc welding the main parameters are as follows:

• Welding current
• Arc voltage
• Travel speed

The other parameters which may be measured and recorded are as follows:

• Wire feed speed (for MIG/MAG) and other processes with a filler wire
• Gas flow rate (shielding, backing and plasma)
• Temperature (pre-heat, inter-pass and post-weld heat treatment)

Some of these instruments allow the length of the weld to be input so that arc energy (kJ/mm) can be calculated.

When measuring voltage and current it is important to do so correctly.

+ Although current can be measured anywhere in the circuit, it is important to ensure that all the current passes through the cable and is not.

+ Voltage measurement is a bit more difficult to get right as the voltage will vary depending where the connections are made. For true arc voltage, it is important to measure as close to the arc as possible.

+ Run out length ( ROL ) / ARC TRAVEL SPEED / welding speed: The arc travel speed is the linear rate that the arc moves along the workpiece. This parameter is usuallyexpressed as inches or meters per minute. Three general statements can be made regard ing the arc travel speed.

Reference document:

+ TWI center

Thank a lot!