Automatic sampler monitors effluent for regulatory compliance, even in freezing temperatures. Explosion-proof, using compressed air (no pumps; no vacuum system) with a self-cleaning action, it moves samples up high lifts (24+m) and over long runs (30+m) from multiple sites simultaneously. The controller can be located far from the sampling site and programmed to sample based on time or by a flow meter. Well-suited for use with tanks, non-pressurized pipes, sumps, open channels and sewers.