简单介绍： 苯气体检测管121s benzene c6h6，measuring range 2 to 5 ppm 5 to 120 ppm 120 to 312 ppm number of pump strokes 4 2 1 correction factor 0.4 1 2.6 sampling time 2 minutes p......
苯气体检测管121s benzene c6h6 产品详情
详情介绍：
苯气体检测管121s benzene c6h6
benzene 21sc6h6performance
measuringrange
2 to 5 ppm
5 to 120 ppm
120 to 312 ppm
number of pumpstrokes
4
2
1
correctionfactor
0.4
1
2.6
sampling time
2 minutes per pumpstroke
detecting limit
0.5 ppm (n=4)
color change
white → darkgreen
reaction principle
c6h6 + i2o5 + h2s2o7 → i2
coefficient ofvariation 20% (for5 to 40 ppm), 15% (for 40 to 120 ppm)
shelflife 3years
correctionsfor
temperature & humidity unnecessary
store the tubes at cool and darkplace.
possible coexisting substances and theirinterferences (note)
substance
concentration
interference
change color by itself
hexane
100 ppm
no effect
no discoloration
toluene
200 ppm
no effect
no discoloration
xylene
300 ppm
no effect
no discoloration
aromatichydrocarbons other than benzene are trapped in the brown layer inthe pretreatment tube.if the pretreatment reagent is entirelyconsumed (whole brown layer turns to dark brown),ahigher reading will be given.
calibration gasgeneration diffusion tubemethod
tlv-twa tlv-stel explosive range
0.5ppm 2.5ppm 1.3 to 7.1%