From Dungeons of Dredmor Wiki
Damage: Special (See Weak Acid Cloud and Weak Acid Pool).
Duration: Special (See Weak Acid Cloud and Weak Acid Pool).
Weak Acid Sprayer triggers two other spell effects: Weak Acid Cloud, which creates a 2 square radius (3x3) cloud of acidic gas, and Weak Acid Pool, which creates a 1x1 pool of acid.
It is triggered by Acid Sprayer Mines.