A phytoplankton fluorescence signal detection circuit

Abstract

The invention discloses a fluorescence signal detection circuit, in particular relates to a phytoplankton fluorescence signal detection circuit with wide range and high accuracy. The phytoplankton fluorescence signal detection circuit comprises a photomultiplier acquisition circuit, an analog signal processing circuit and a digital processing circuit, wherein phytoplankton fluorescence signals are processed by a plurality of operational amplifiers with different gains in the analog signal processing circuit, so that the measurement range of the phytoplankton fluorescence signals is increased; then each operational amplifier is used for carrying out analog-to-digital conversion by virtue of an analog-to-digital signal converter; finally, digital values processed by the analog-to-digital signal converters are sent to the digital processing circuit for data processing, so that the phytoplankton fluorescence signals with relatively high accuracy are obtained. The phytoplankton fluorescence signal detection circuit is capable of carrying out high-accuracy and wide-range detection on the phytoplankton fluorescence signals.

Description

technical field [0001] The invention relates to a fluorescent signal detection circuit, in particular to a fluorescent signal detection circuit of phytoplankton. Background technique [0002] The traditional fluorescent signal detection circuit uses the photomultiplier tube acquisition circuit to amplify the fluorescent signal, and then sends it to a high-precision analog-to-digital signal converter (hereinafter referred to as AD converter) after processing by an analog circuit to realize the acquisition of fluorescent signal. High precision digitization. The digitization accuracy of this circuit depends on the high-precision AD converter. Since the effective input analog signal range of a single AD converter is limited, the output signal of the analog signal processing circuit is limited, which in turn affects the detection of the fluorescent signal input by the circuit. precision. For example, a single AD converter is used in a signal processing circuit for vitamin fluor...

AI Technical Summary

Problems solved by technology

At the same time, due to the high-precision requirements of the system, the selected high-precision AD conversion device usually has a conversion digit of more than 24 bits. This type of AD converter has high precision, and the actual voltage or current value that the circuit can distinguish is too low. The design requirements of the signal are relatively high, and some interference of the analog circuit device itself is easy to introduce noise and affect the actual acquisition accuracy

[0003] The detection method of traditional phytoplankton fluorescence detection circuit is similar to the form of the signal processing circuit of above-mentioned vitamin fluorescence detection, using traditional fluorescence signal detection circuit to carry out phytoplankton fluorescence signal detection can not meet the requirements for phytoplankton (phytoplankton types are various, body size There is a high requirement for the quality of the fluorescent signal with a large difference), and its response to the change of several orders of magnitude is very low. Only the signal that falls within the effective detection range can achieve high-precision signal detection, and the detection value is often too low or a phenomenon exceeding the detection value

And because of the non-reproducibility of on-site phytoplankton fluorescence (different from other static detection methods using containers, on-site phytoplankton fluorescence detection can only be detected by continuous inflow of flowing sea water and real-time detection), so the traditional fluorescence signal detection circuit is used for phytoplankton detection. Plant fluorescence detection is more prone to missed detection

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