With contain haloid (fluorine, chloric, bromic, iodic) the instrument calls the leak hunting that gas is search gas haloid leak detector. This kinds of instrument divides kind: It is sensor firstly (namely probe) with by check photograph connective calls stationary (also say inside probe type) haloid leak detector; It is sensor secondly (suck a gun namely) in by check of outside search call portable (type of the probe outside also saying) haloid leak detector. Search gas has carbon of fluorine Lyons, chloroform, iodoform, 4 chloridize to wait, among them chloric Lyons is best. Sensitivity of haloid leak detector can amount to 3.2×lO^{- 9}Pam³／ S.

(1) job principle and structure
Metallic platinum is in 800 ～ 900^OThe meeting below C temperature happens ion blasts off, when encountering haloid gas, this kind of emissive meeting increases quickly. This is so called “ haloid effect ” , use the haloid leak detector that this effect makes.
Sensor is a diode, add heater, cathode (outside canister) , zincous (inside canister) all make with platinic material. Positive pole is heated after silk heats, blast off ionic, the ion that is received by cathode flows by galvanometric (or amplifier) the directive comes out, and have acoustics directive.
Electric part by heat power source, direct current source, ionic banish is big implement, output shows reach the composition such as portable inspiratory device power source.

(2) function checks a method
Time of sensitivity, reaction reachs the main performance data that restoring time is haloid leak detector. What its test method and leak detector of helium mass spectra is identical, here no longer give uncecessary details. But, the chroma of the directive of haloid leak detector and haloid gas concerns: General, directive of low pH indicator is linear, dispute of medium pH indicator is linear, and become occurrence saturation of the instrument when concentration is very high or toxic phenomenon. When undertaking function test or leak hunting so, the chroma of the haloid gas that enters sensor is unfavorable prep above 1/1000000.
Sensor of haloid leak detector should mix stationary LO^{- 1}～ 10^OWork inside Pa pressure limits, exorbitant or pressure is too low meet those who bring about instrument sensitivity to drop.

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