Wide humidity environment-friendly humidity sensing device and control method thereof

Abstract

The invention discloses a wide humidity environment-friendly humidity sensing device and a control method of the wide humidity environment-friendly humidity sensing device. The device comprises a microprocessor and a humidity sensing module, wherein the humidity sensing module is connected with the microprocessor, and comprises a capacitance-type humidity sensing element and a NTC (negative temperature coefficient) temperature measuring unit; and a monobus data transmission manner is adopted in the microprocessor and the humidity sensing module. According to the invention, a new-type humidity sensitive element made of organic polymer material is adopted, has the characteristics of wide humidity sensing range, rapid response and strong anti-pollution ability, no need of heating and cleaning, and stable and reliable performance in long-time use and the like; and except a sensor and a ceramic feed through seat, components contacted with water are stainless steel materials. The wide humidity environment-friendly humidity sensing device provided by the invention has absolute advantages compared with a humistor in the market, and simultaneously, has the characteristics of high cost performance, low energy consumption, better pollution resistance, quick response time, excellent linearity, high reliability and long-time stability, and capability of being used for linear voltage or frequency output, rapidness in dehumidification under long-time saturation and the like.

Description

technical field [0001] The invention relates to the technical field of sensors, in particular to a wide-humidity environment-friendly humidity sensor device with high reliability, strong anti-interference ability and high stability and a control method thereof. Background technique [0002] At present, the product levels of humidity sensors of various manufacturers at home and abroad are different, and the quality and price are quite different. It is indeed difficult for users to choose the ideal product with the best performance and price ratio. There are many domestic and foreign humidity sensor products in the domestic market, capacitive humidity sensor is more common, and the types of humidity sensing materials are mainly polymers, lithium chloride and metal oxides. The advantages of capacitive humidity sensor are fast response, small size, good linearity and stability. Some foreign products also have high temperature working performance. However, most of the products t...

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Problems solved by technology

However, most of the products that achieve the above performance are foreign famous brands, and the prices are relatively expensive.

Some low-priced products of capacitive humidity sensors on the market often fail to reach the above level, and the linearity, consistency and repeatability are not ideal, below 30% RH (RH is relative humidity, that is, relative humidity), 80% Severe deformation of the wet section above %RH

Some products use single-chip microcomputer compensation and correction, but it is easy to cause "step" jumps in the humidity, which reduces the accuracy; at the same time, it also leads to the disadvantages of poor consistency and poor linearity

Regardless of the high-grade or low-grade capacitive humidity sensor, the long-term stability is not ideal. Most of the long-term use drifts seriously. It often causes dozens of RH% errors, and most capacitive humidity-sensitive components do not have the performance of working at temperatures above 40°C, and are often prone to failure and damage

The capacitive humidity sensor is also lacking in corrosion resistance, and often requires high environmental cleanliness. Some products also have light failure, electrostatic failure, etc. The metal oxide is a ceramic humidity sensor, which has the same performance as the humidity sensor. Advantages, but in a dusty environment, the ceramic pores will be blocked and the components will fail. The method of electrification and dust removal is often used to deal with it, but the effect is not ideal, and it cannot be used in flammable and explosive environments. Aluminum oxide moisture-sensitive materials cannot overcome Its surface structure has the weakness of "natural aging", the impedance is unstable, and the metal oxide ceramic humidity sensor also has the weakness of poor long-term stability

The long-term stability of the lithium chloride humidity sensor cannot be replaced by other moisture-sensing materials

[0003] Now domestic and foreign products are very competitive, depending on the performance, stability, and humidity probes used. At present, the number of domestic sensor manufacturers is already very large, but there is still a lack of top well-known brands, and the high-end product field is occupied by foreign brands. , most of the manufacturers gather in the field of low-end products, and at the same time lack core technologies, research and production are separated

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