CN2248871Y - Pocket microcomputer instrument for measuring dust - Google Patents

Abstract

The utility model relates to a pocket microcomputer instrument for measuring dust, belonging to the technical field of the particle concentration measurement of the suspended substance on the atmosphere on the physical class. The instrument adopts the principle of the beta ray absorption method of the nuclear technology and the single-chip microcomputer technology and a detector adopts a beta counter tube and a special high voltage module. The microcomputer adopts a 89C51 single-chip microcomputer and the beta counter tube is connected with an analog signal processing device. Signal is input into the single-chip microcomputer and the dust concentration is automatically showed on a display. The instrument for measuring dust has the advantages of high precision, high stability, small volume, light weight, less energy consumption, data storage, automatic record and printing list.

Description

Pocket microcomputer dust gauge

The utility model relates to the air monitering instrument of a kind of environmental protection and labour protection, belongs to the technical field that the physics class is measured the air suspension particle concentration.

Dust measuring method at present both at home and abroad commonly used has weight method, optical absorption method, light scattering method, crystal oscillator method and β radiation absorption method etc., and wherein β radiation absorption method has and measures fast, accurately and with advantages such as the physicochemical property of dust is irrelevant.By portable dust measuring instrument is adopted.Use wider WCY-1 type microcomputer dust gauge at present and adopt β radiation absorption method exactly, but its detecting element is a halogen counter, sensitivity is low, and range is little, and Measuring Time is long partially, generally need 2-3 minute, the partial circuit of sampling pump and main frame is wanted Alternating Current Power Supply, and sampling and the surveying instrument comparison heaviness that is integrated must two people be operated, and this instrument can not use in inflammable and explosive place, and the scope of application is limited.

About the document of prior art, the data retrieved storehouse has: (1) science abstract: INSPEC (NO.2) 1969-1994; (2) engineering index: EI Compendex (No.8) 1970-1994; (3) world patents index: WPI (No.350,351) 1963-1994.Finding pertinent literature has two pieces, INSPEC Abstract A90 151262, and B90011470 reports light scattering method dust gauge and common dust gauge respectively.Domestic database has: " Chinese appropriate technology achievement storehouse " No.88201039, No.09029082R.More than retrieval there is no the instrument of useful β radiation absorption method monitoring airblrne particulates (dust, floating dust, particle).The utility model patent that " microcomputer dust gauge " arranged in the Chinese patent database, application number is 87204329, but this patented technology is inventor's innovation and creation a few years ago, and the development work to dust measuring instrument has new substantial progress again now, the application of utility model patent is proposed for this reason.

The purpose of this utility model provides a kind of pocket dust gauge makes dust gauge lighter, volume-diminished, and weight greatly alleviates, and possesses the automatic printing function of data, and is practical more.

The utility model adopts β radiation absorption method principle in the nuclear technology, and detecting device is selected little beta counter tube of volume and corresponding high-pressure modular for use, and microcomputer adopts the 89C51 single-chip microcomputer of Cmos type, the mathematic(al) mode of its measuring principle: $C={\mathrm{\μ}}_S.\frac{1}{V}\ln \frac{N_1}{N_2}$ In the formula,

Dust concentration value (the mg/m of C-measuring point ³);

μ _s---mass absorption coefficient related parameter (g/cm arranged ²);

N ₁---the β particle counting that blank film records;

N ₂---the β particle counting that the dirt filter membrane records;

V---the volume of air (m that gathers when gathering dust ³).

Sampling thief is the prior art of Chinese patent 87204329.On a measuring point, utilize the filter membrane of regulation to use sampling thief to sample.The mesopore of sampling folder is a thieff hatch, the datum hole when stomidium is measurement.The folder of will sampling after sampling finishes inserts to be measured in the chamber, in stomidium position measuring N ₁, in mesopore position measuring N ₂When measuring N ₁, N ₂, μ _sBe solidificated among the EPROM of single-chip microcomputer, as long as with the digital input sample volume (with the unit of being upgraded to) of instrument, the just concentration value (mg/m of liquid crystal display dust (floating dust, particle) on display immediately ³).Its principle of work is shown in the pocket microcomputer dust gauge of Fig. 1 block diagram.

The present utility model people is that shape, the structure with regard to dust gauge proposes to be suitable for practical new solution on its patent that formerly obtains " microcomputer dust gauge " (Chinese patent 87204329) basis.According to this scheme, ¹⁴C source activity district is the face source of φ 8mm, and intensity is 10000～15000Bq (Bq (becquerel)).The half life period of β radiation source is 4960 more than 5 years the βShe Xiantanceqi life-span in the instrument, and full-shield is harmless.Filter membrane is measured the chamber and is used for placing the sampling folder, ¹⁴The β ray that the C source emits absorbs by blank film and sampling film, convert pulse signal to through the detector beta counter tube, through analog signal processing device signal is amplified, differentiate and shaping, the shaping afterpulse is by in the microcomputer interface input dedicated microcomputer, and this microcomputer adopts single-chip microcomputer, and paired pulses is gathered, processing and computing, on LCD, demonstrate the concentration value of dust again by microcomputer interface, can on-the-spot reading.This microcomputer is stored intermediate result and the net result of measuring, and is equipped with the dedicated microcomputer printer, the result who measures can be printed list.The pocket microcomputer dust gauge of the utility model accuracy of measurement is≤± 10%; 8 hours its stability errors of instrument continuous working are≤± 10%.

Pocket microcomputer dust gauge of the utility model and prior art, promptly commercially available patented product WCY-1 microcomputer dust gauge contrast under the situation that main measurement index remains unchanged, has following more practical good effect:

1, volume-diminished: adopt the beta counter tube detector to replace the photoelectricity scintillation detector, adopt single-chip microcomputer to replace original single card microcomputer, thereby dwindled volume greatly.The volume contrast of two kinds of dust gauges is respectively 210 * 215 * 95mm, 178 * 120 * 50mm.

2, weight saving: microcomputer dust gauge weight is 3kg, and the weight of pocket microcomputer dust gauge falls sharply to 0.95kg.

3, save energy consumption: the former power consumption is 600mA, and the latter then reduces to≤50mA.

4, stored data: the former can not stored data, and the latter then can store the data of 55 measuring points, and printablely goes out list.

The utility model has two accompanying drawings:

The pocket microcomputer dust gauge of Fig. 1 theory diagram

Fig. 2 beta counter tube and corresponding high-pressure modular detector circuit thereof.

Embodiment

Design according to above-mentioned ultimate principle and device.Detector adopts J419 type beta ray counting tube and high-voltage power module VH-460 thereof.Will ¹⁴The β ray that C emits passes blank film and sampling film and converts electric impulse signal to, the input signal treating apparatus.Input microcomputer after signal processing apparatus amplifies, differentiates, is shaped the signal of input.Microcomputer adopts the EPROM type 89C51 single-chip microcomputer of CMOS chip.Single-chip microcomputer is counted, volume (liter) by the keyboard input sample gas on the panel then, single-chip microcomputer connects the program of setting respectively to blank film, can draw the concentration value of dirt after the sampling film processing computing, on the display of integrated circuit 7211 and LCD panel 4212 compositions, demonstrate the result of measurement.In addition, external unit has mini-printer and power supply thereof, charger etc.Above-mentioned each parts connect as shown in Figure 1.

Claims (4)

1, a kind of pocket microcomputer dust gauge comprises ¹⁴The β radiation source of C, filter membrane, beta rediation detector, analog signal processing device, microcomputer, display, high-voltage power supply, electric battery and external unit mini-printer and power supply thereof etc., it is characterized in that detector adopts beta counter tube, be connected with analog signal processing device, signal input single-chip microcomputer provides dust concentration automatically and shows on display.

2,, it is characterized in that the high-voltage power supply of beta counter tube adopts the VH-460 high-voltage power module according to right 1 described dust gauge.

3, dust gauge according to claim 1 is characterized in that microcomputer adopts the EPROM type 89C51 single-chip microcomputer of CMOS chip, and the mathematic(al) mode of measuring principle has been solidificated among the EPROM of single-chip microcomputer.

4, dust gauge according to claim 1 is characterized in that display adopts liquid crystal display.

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