Device and method for measuring long stroke displacement based on Hall effect

Abstract

The invention belongs to the technical field of physical parameter measurement and relates to a device for measuring long stroke displacement based on the Hall effect. The device comprises a single chip microcomputer, a constant current source, a signal processing circuit, an analog-to-digital converter and a sensor array, wherein the sensor array is at least one group of linear hall sensors; each group of the linear hall sensors are uniformly and linearly arranged on a PCB (Printed Circuit Board); the space between the adjacent linear hall sensors is not less than the size of a magnet on a magnetic float in the arrangement direction of the sensor array; the differential outputs of the linear sensors are multiplexed with two differential voltage signal transmission lines through an n-channel analog multiplexer; the two differential voltage signal transmission lines are connected with an input interface of the signal processing circuit; the two adjacent PCBs are connected through an expansion interface; and each group of the linear hall sensors are powered by one same constant current source in a time sharing manner. The device has the advantages of low power consumption, fewer adopted devices, convenience in maintenance and lower cost.

Description

technical field [0001] The invention belongs to the technical field of physical parameter measurement, and relates to a Hall effect displacement measuring device and a measuring method, in particular to a Hall displacement measuring device and a measuring method for long-stroke displacement measurement through a linear Hall sensor. Background technique [0002] At present, the transmitter part of the magnetic float level gauge uses a reed switch sensor. Some technical parameters of the transmitter of the magnetic float level gauge: [0003] Liquid density: >0.4g / cm3, [0004] Maximum range: 0-6m, [0005] Resolution: ±1cm, [0006] Signal transmission mode: (4-20) mA (two-wire system). [0007] Magnetic float level gauge is a kind of liquid level instrument that has certain requirements for measurement accuracy (resolution: ±1cm), but the requirements are not too high, and its price is relatively moderate. If higher accuracy is required, such as ±1mm accuracy, other ...

AI Technical Summary

Problems solved by technology

The switch-type Hall sensor is an active device, coupled with the auxiliary circuit, the measurement range will not be able to realize the thin strip device

[0012] 3. Using a switch-type Hall sensor, as the measurement length increases, the circuit complexity increases exponentially, and its low-power measurement method will be meaningless

[0013] 4. Using a switch-type Hall sensor, as the measurement length increases, the complexity of the circuit increases exponentially, and the cost of the measurement equipment will greatly exceed that of using a reed switch, so the application is limited

If this measurement principle is used to achieve long displacement measurement, either the length of the magnet of the magnetic float will be increased, or the number of sensors to be used will be greatly increased, but the former may lead to ineffective measurement, while the latter will inevitably increase the cost

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