The invention relates to a
pipe orifice variable plug-in type sampling instrument which structurally comprises a steady flow buffer
pipe used for receiving a pumped polluted
water sample and steadily conveying the polluted
water sample, a pump
pipe connecting mechanism fixedly connected with a polluted
water sample output pump pipe, a flow dividing pressure regulating valve used for regulating the pressure of the
water flow of the polluted water sample, a pressure gauge for detecting the pressure of the
water flow, an arc sampling core pipe fixed in the steady flow buffer pipe, a sampling hose connected with an outward extending end of the arc sampling core pipe, and a concentric type flow
regulator used for regulating the flow of the collected water sample. The sampling instrument provided by the invention changes the composition, the structure and the working principle of an original
organic matter polluted water sample collecting device, and has the characteristics of small size, light weight, wide application range, convenience for carrying and installing, simplicity in operation, safe use, avoidance of polluting the sample in the collecting process, etc., so that the fidelity of the collected sample is increased, the sample collecting cost is lowered, the safety of staffs and equipment is guaranteed, and the universality of the sampling instrument is improved.