Measurement system for sea water temperature

Abstract

The invention disclose a measurement system for sea water temperature, which comprises a nonequilibrium bridge circuit unit, a constant current source generation circuit unit, a voltage follower circuit unit and a filter amplifier circuit unit, wherein the input end of the nonequilibrium bridge circuit unit is connected with an anode of direct voltage through a resistor R8; the output end of the nonequilibrium bridge circuit unit is connected with the voltage follower circuit unit; the output end of the constant current source generation circuit unit is connected with the nonequilibrium bridge circuit unit; the voltage follower circuit unit is connected with the filter amplifier circuit unit through a resistor R9 and a resistor R10; and the input end of the constant current source generation circuit unit is connected with a plus 5V power supply. The measurement system has the characteristics of high sensitivity, good stability, long service life and the like; the measurement precisionof the measurement system is much higher than that of the traditional thermocouple or the pressure type thermodetector; and the measurement system has obvious technical advantages in the conventionaltemperature measurement range (minus 2 DEG C - 30 DEG C) of the sea water.

Description

technical field [0001] The invention belongs to the technical field of marine engineering, and in particular relates to a high-stability seawater temperature measuring device based on a platinum thermal resistance sensor. technical background [0002] Seawater temperature is a physical quantity that reflects the thermal state of seawater, and is also one of the most important factors in the monitoring of ocean hydrology. It is often used as a basic index to study the properties of water masses and describe the movement of water masses. At present, the probes for measuring seawater temperature mainly include thermistors, platinum thermal resistances and thermocouples. Thermocouples mainly have advantages in high-temperature temperature measurement conditions. For example, the temperature sensor near the hydrothermal vent is mainly designed based on the principle of thermocouple temperature measurement, but the accuracy of thermocouple thermometers is not high in the conventio...

AI Technical Summary

Problems solved by technology

Thermocouples mainly have advantages in high temperature temperature measurement conditions. For example, the temperature sensor near the hydrothermal vent is mainly designed based on the principle of thermocouple temperature measurement, but the accuracy of thermocouple thermometers is not high in the conventional temperature measurement range of seawater.

The accuracy of the thermistor and the platinum resistance are basically in the same order of magnitude. The thermistor is low in cost and easy to manufacture, while the linearity of the platinum resistance is better and the stability is stronger, but due to the small resistance value, complex conditioning is required The circuit appears to be more costly to design

At present, thermistors are widely used as temperature sensors in CTD profilers at home and abroad. This method lacks stability, and the calibration formula between temperature measurement frequency and temperature value is complicated.

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