Liquid level detection device, liquid level detection method and sample analyzer

Abstract

The invention discloses a liquid level detection device and method and a sample analyzer, and the liquid level detection device comprises a pulse signal providing part which is used for generating a pulse signal; the impedance element is used for providing impedance and is connected with the sampling needle; the impedance element and the capacitor of the sampling needle jointly form an RC part; the RC part receives the pulse signal and performs RC delay processing to obtain a first output signal; the window comparison part is connected with the RC part, and is used for comparing the first output signal with a first threshold value and a second threshold value respectively to obtain a first comparison result and a second comparison result, and taking a result obtained by carrying out logic AND operation on the first comparison result and the second comparison result as a second output signal; and the main control part is connected with the window comparison part and is used for determining whether the sampling needle is in contact with the liquid level or not based on the received second output signal. According to the invention, the detection sensitivity can be ensured, and electromagnetic radiation interference can be reduced.

Description

technical field [0001] The invention relates to the technical field of medical devices, in particular to a liquid level detection device, a method thereof, and a sample analyzer. Background technique [0002] In the field of medical devices, the use of sampling to absorb and release liquids such as samples is a common application scenario. When sucking or releasing liquid, the sampling needle often needs to contact the liquid level. In order to control the sampling needle to perform the liquid sucking or releasing operation and ensure the accuracy of the above operation, liquid level detection is very necessary. [0003] The liquid level detection methods in the prior art mainly include: [0004] 1. Build a Wheatstone bridge to detect whether the sampling needle is in contact with the liquid level. Based on the fact that the sampling needle will generate a fast-changing electrical signal before and after contacting the liquid, because the fast-changing electrical signal is ...

AI Technical Summary

Problems solved by technology

[0004] 1. Build a Wheatstone bridge to detect whether the sampling needle is in contact with the liquid surface. Based on the fact that the sampling needle will generate a fast-changing electrical signal before and after it touches the liquid surface, because the fast-changing electrical signal is not easy to detect, it is easy to cause the risk of false detection

[0005] 2. Using an oscillating circuit to detect whether the sampling needle is in contact with the liquid surface is prone to failure to vibrate, and there are large electromagnetic radiation problems

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