The test method covers the detection of the corrosiveness to copper of aviation gasoline, aviation turbine fuel, automotive gasoline, natural gasoline, or other hydrocarbons having a Reid Vapour Pressure no greater than 18 psi. The cover of the bath has six openings, each with a lid and hook for suspending a copper corrosion test vessel. The openings can also accommodate test tubes in holders. The temperature range is from ambient +5°C to 250°C. This is the widest temperature range on the market, enabling users to test the corrosiveness to copper at very high temperatures. The bath is equipped with a bath drain, which enables safe and easy bath fluid replacement. A cooling coil is integrated to work at temperatures close to the ambient temperature. An optional cover with nine openings is available to test nine samples, larger baths for 18 or 63 positions are available.