Calibration apparatus for chemical alarm

Abstract

The invention discloses a calibration apparatus for a chemical alarm. The calibration apparatus is mainly used for preparing accurate-concentration standard gas with a concentration of 10<-10> to 100 mg / m3 or dilution of 1 to 10<12> times from a liquid or gaseous standard chemical and testing the metering performances like response sensitivity of the chemical alarm so as to facilitate research on apparatus metering or analytical methods. The apparatus comprises a stepping motor (6-1) which drives injection of a liquid or bottled high-concentration gaseous standard chemical (9-2) in a syringe (16-1) into a gasifier (10), and the liquid or bottled high-concentration gaseous standard chemical (9-2) is evaporated or diluted by zero gas (9-1) so as to obtain primary-standard gas (9-5) with a concentration of 10<-3> to 100 mg / m3; to obtain a lower concentration, the primary-standard gas stored in a second syringe (16-2) is diluted in a mixer (14), and secondary-standard gas (9-5) with a concentration of 10<-10> to 100 mg / m3 is output; and standard gas is switched in virtue of a three-way solenoid valve (13) and enters the alarm or detector (9-4), alarming time (12) of sound or light emitted by the alarm is recorded, and response sensitivity of the alarm is calculated.

Description

technical field [0001] The invention discloses a chemical alarm verification device, which is mainly used for preparing liquid or gaseous standard chemicals into 10 -10 ~100mg / m 3 Or the dilution is 1~10 12 times the standard gas of any accurate concentration and test the measurement performance of chemical alarm response sensitivity, so as to be suitable for the research of measurement process or analysis method such as the development, production, verification and calibration of gas alarm or detector and other instruments. The device and system involved in the invention include a primary standard gas preparation mode, a secondary standard gas preparation mode and a photosensitive controller for testing the response time of an alarm. In the first-level standard gas preparation mode, the first stepper motor (6-1) drives the liquid standard chemical contained in the first syringe (16-1) to inject into the vaporizer (10) or is supplied by the second gas flow rate. The high-co...

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Problems solved by technology

[0008] (3) Poor reproducibility The accuracy of gas standard substance preparation by diffusion method is greatly affected by the size of diffusion tube or diffusion cell and capillary, system temperature and pressure [Chi Xidong, Cui Jiusi, Cui Jiusi, Jing Haining. Benzene Diffusion Tube Gas Standard The development of substances [J]. China Environmental Health, 2000, 3 (3, 4): 85-91], so it needs to be strictly controlled. For example, when the temperature changes by ±0.1°C, the change of its diffusivity can reach ±0.49%. Higher requirements for the process and operation of the verification device [Fang Zheng. A verification device for breath alcohol content detector [P]. Utility model patent, CN201320830646.3, 2013-12-16]

At present, the gas distribution device realized according to the principle of spray gasification, because the obtained concentration is greater than 0.01mg / m 3 [Wang Xin, Li Shanmao, Wang Jizhang, Li Wei, etc. A device for atomizing and gasifying liquid organic matter [P]. Invention patent, CN201110033615.0, 2011-01-31], so the alarm that requires high sensitivity cannot be achieved instrument or detector requirements

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