Solinst 425 Mk3 Discrete Interval Sampler The Model 425 Discrete Interval Sampler is a stainless steel groundwater sampler with LDPE tubing mounted on a convenient reel and is pressure activated using a hand pump. The sampler is pressurized before being lowered, and upon retrieval, to prevent mixing. Pressure is released at the desired depth to obtain a sample. Ideal for sampling from depths as much as 90 m (300 ft) below water level. Solinst 425 Datasheet Model 425 1.66" dia. Operator's Manual Model 425 1" dia. Operator's Manual Model 425 2" dia. Operators Manual Features: High quality, discrete zone samples Profile wells or open bodies of water Easy operation and transportation No mixing of water from different levels Avoids purging and disposal of purged water