The invention provides a suction type water sampler and a unit suction type underlying
water sampling system, belonging to the technical field of marine monitoring. A main mechanism of the
water sampling system is the suction type water sampler; the suction type water sampler comprises a
water sample cup, a sampler seat, a sampler cover, a valve rod, a spring, a diaphragm and a
valve seat, wherein the diaphragm is pressed between the sampler seat and the sampler cover, so that an upper cavity and a lower cavity are formed; the upper cavity is communicated with a
water sampling area by means of a through hole formed in the sampler cover; the lower cavity is communicated with, by means of a water inlet hole formed in the sampler seat, the
water sample cup screwed down on the sampler seat, and is communicated with the water sampling area by means of a controllable gap between the valve rod and the
valve seat; the valve rod sequentially passes through the sampler cover, the diaphragm, the sampler seat and the
valve seat from top to bottom; a spring is installed between the upper end of the valve rod and the sampler cover, and the valve seat is sealed by using the spring to press the valve rod; the valve rod and the diaphragm are pulled to move upwards, the air in the
water sample cup is sucked into the lower cavity, and the water in the water sampling area is sucked into the water sample cup, so that water sampling is completed. The suction type water sampler and the unit suction type underlying water sampling
system avoid the problem that water samples are easily confused, expand the sampling range of the water samples, and improve the sampling quality of the underlying water samples.