A liquid sampling device and its control method

Abstract

The invention discloses a liquid loading device and a control method thereof. The device comprises at least one hollow sample needle; the tail end of the sample needle is connected with a first valve by a pipeline; the pipeline between the sample needle and the first valve is also connected with a pressure sensor and a sample injector; a pipeline passing through the first valve is divided into two paths by a three-way pipe; one path of the pipeline is connected with a second valve; the other end of the second valve is an open end; and the other path of the pipeline is connected with a pressure injector. The invention further discloses the control method of the liquid loading device. The liquid loading device has the advantages of simple and flexible structure, high accuracy, low cost and the like.

Description

technical field [0001] The invention relates to a liquid sampling method and a device thereof, in particular to a method and a device for adding trace liquid samples. Background technique [0002] At present, the existing liquid level detection devices generally use immersion photoelectric liquid level sensors, reed switch sensors, ultrasonic sensors or capacitive sensors to monitor the liquid level. [0003] The immersion photoelectric liquid level sensor consists of a pair of light-emitting diodes and photosensitive elements at a certain angle to each other. This detection method is generally not suitable for liquid level detection of small containers, and with the increase of use time, the immersion photoelectric liquid level sensor The Detection accuracy will decrease. In addition, the immersion photoelectric liquid level sensor has low accuracy in measuring liquid level and is not suitable for precision measurement. [0004] Although the detection method of the reed s...

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Problems solved by technology

[0003] The immersion photoelectric liquid level sensor consists of a pair of light-emitting diodes and photosensitive elements at a certain angle to each other. This detection method is generally not suitable for liquid level detection of small containers, and with the increase of use time, the immersion photoelectric liquid level sensor The Detection accuracy will decrease

In addition, the immersion photoelectric liquid level sensor has low accuracy in measuring liquid level and is not suitable for precision measurement.

[0004] Although the detection method of reed switch is cheap and simple, its volume is too large, it is not suitable for liquid level detection of small containers, and it is also not suitable for precision measurement.

[0005] Ultrasonic sensors are composed of a pair of ultrasonic generators and ultrasonic sensors. This detection method has high accuracy, but the cost is high and it is not suitable for large-scale use.

[0006] The capacitive sensor detects the liquid level by changing the effective electrode area and distance between the two stages of the capacitor to realize the capacitance change. This method requires high debugging, and the liquid to be tested must be a conductive solution (the capacitance of the non-conductive solution changes very little, and it is very difficult to realize).

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