Automatic sampler for milk testing or the like - avoids contamination by air or by liquid from earlier sampling

摘要

An automatic sampler consists of a pipette which projects into the pipe carrying the liq. to be sampled and which is connected at its other end to a needle by which the sample is injected into the sample container. The needle is moved between one position where it can reject the liq. sampled and another position where it can pierce the cover of the sampler container and inject the sample into it. The movement is brought about by a cam actuated by the raising and lowering of the sample container. The appts. is esp. for sampling milk in bulk for analysis and grading according to its bacteriological state. Any liq. which remains in the system from a previous sampling is discharged there from before the new sample is taken and cannot contaminate it. The new sample is injected into its receiver after the needle has pierced the cover of the receiver when the needle is withdrawn, the cover seals itself, so that air cannot contaminate the sample. The sampler can be used on mobile or fixed collection systems.