Method for manufacturing joined body

A method for manufacturing a joined body, the method comprising:

• clamping a first combination of metal workpieces between a first pair of electrodes, the first combination of metal workpieces being provided for measurement of a resistance value between the first pair of electrodes;
• applying a constant measurement current between the first pair of electrodes;
• measuring a resistance profile between the first pair of electrodes over time based on (i) a value of the constant measurement current and (ii) a value of a voltage between the first pair of electrodes;
• clamping a second combination of metal workpieces between a second pair of electrodes, the second combination of metal workpieces being equivalent to the first combination of metal workpieces;
• applying a welding current between the second pair of electrodes, the welding current flowing through the second combination of metal workpieces to form the joined body;
• and
• varying magnitude of the welding current in accordance with the resistance profile measured.