Structure of Niskin water sampler

 It consists of a water sampler made of polyvinyl chloride and a lid. The upper and lower lids are closed by the elasticity of a rubber tube or a metal spring (Figure 1). To remove the sample water from the water sampler, open the air vent at the top of the sampler and push in the water sampling port (PET cock) at the bottom of the sampler. The detailed structures of the upper and lower lids, the air vent, and the water sampling port (Pette cock) are shown in Figure 2. All of them are sealed with O-rings to prevent seawater from mixing with other seawater.

Fig. 1 Structure of Niskin water sampler

上蓋　Top Lid

採水筒　Water sampling bottle

ゴムチューブ(又はバネ)　Rubber tube (or spring)

下蓋　Lower cover

空気孔(エアベント)　Air vent

プッシュロッド　Push rod

ワイヤクランプ　Wire clamp

リリースブロック　Release block

ナイロンテグス　Nylon Tegs

採水口(ペットコック)　Water sampling port (PET cock)

Fig. 2 Niskin water sampler Aperture mechanism

蓋　Lid

Oリング　O-ring

空気孔　Air Hole

エアベントバルブ　Air vent valve

空気　Air

採水口　Water sampling port

ガイドピン　Guide pin

プルディスク　Pull Disk

ペットコック　Petcock

海水　Seawater

穴　Hole

ガイドピン　Guide Pin

a) O-rings are fitted into the upper and lower openings of the water collection bottle, and the O-rings and the lid are sealed tightly together to maintain a tight seal. b) A screw-in valve (air vent valve) with a T-shaped hole is inserted into the air hole. When the valve is screwed in, the O-ring is crushed and the hole in the valve is blocked. Conversely, when the valve is loosened by twisting it, air enters the water sampling bottle. c) A T-shaped through-hole cock (petcock) is inserted into the water sampling port, and by sliding the cock back and forth, the water sampling port can be opened and closed. When the cock is pulled out, the hole is blocked by two O-rings. When the cock is pushed in, the hole is released and seawater flows out. The pull disk, which serves as a handle for sliding the cock, has a small hole in it, and this hole must be aligned with a metal rod (guide pin) protruding from the water sampling cylinder in order to push the cock in, making it difficult to accidentally release the cock.