日本GASTEC气体检测管使用方法及注意事项

Information on the individualdetector tubes

Name and chemicalformula	The name of the substance to be measuredwith this detector tube and its chemical formula
Detector tubenumber	The identification number of the detectortube
Externalappearance	The external appearance of the detectortube(s) is briefly illustrated. Both ends of the tube(s) should bebroken and prepared before measurements as shown below
Measuringrange	The range of the substance concentrationsthat can be measured with the detector tube. The standard measuringrange, or range of the printed calibration scale is given in theshaded box. Some lower limit values of the standard measuringranges are parenthesized when they are not printed on the tubes butonly their scale lines are printed.
Number of pumpstrokes	The number of pump strokes required formeasuring a given range of concentrations. The volume to be sampledwith those strokes is given in the parentheses. The standard pumpstrokes and the standard sampling volume are given in the shadedbox. With most Gastec detector tubes,the standard pump strokes areprescribed as 1 (the standard sampling volume is 100mL).
Correctionfactor	When measuring an extended range ofconcentration, that is, when the measurement is performed withother than the standard number of pump strokes, the tube readingshould be corrected by multiplying the reading by the prescribedcorrection factor.
Sampling time	A waiting time for 100 mL (or 50 mL forhalf strokes) to be sampled in the detector tube after the handleof the Model GV-100 Gas Sampling Pump is fully (or half way for 50mL) pulled out. When you pump more than once (n times), the waitingtime for you to read the tube, that is, the measuring time is: Measuring time = sampling time x n.
Detectinglimit	The lower limit of the substanceconcentration that the detector tube can detect. This minimalconcentration can be recognized by a slight colour change at theentrance of the detecting layer. This value is followed by theparenthesized number of pump strokes required for measuring thisconcentration.
Colour change	Indicates how the detecting layer of thedetector tube will change its colour by the reaction with thetarget substance. This is shown in the form of: Original → Changed colour
Reactionprinciple	The chemical reaction of the targetsubstance with the reagent(s) in the detector tube is brieflystated.
Coefficient ofVariation	An indicator of the accuracyof the detector tube. It represents how the tube indications maydeviate from their mean value in percentage: Coefficient ofVariation= Standard devlation( ) x 100 (%)   Mean value ( )
Shelf life	The period that Gastec will warrant thequality of the detector tubes, provided that they are stored underthe prescribed conditions
Corrections for temperature& humidity	For detector tubes whose indications areaffected +/- 10 % or more by the fluctuation of temperature orhumidity, the tube readings should be corrected. Whether or not such corrections are necessary are indicatedhere. The correction data, if necessary, is provided in the instructionsheets provided with the detector tubes.
Storagecondition	To keep the high quality of Gastec detectortubes, it is necessary to store them in a cool and dark place. Itis recommended to store the tubes in the refrigerator, i.e, 0 to10ºC(32 to 50ºF) even if the tube labels describes cool and darkplace.
Possible coexistingsubstances and their interferences	Substances that are liable to coexist withthe target substance and their influences on the tube indicationsare listed here. The column "Concentration" Iists the lowestconcentration that may affect the indication +/-10 % or more, orthe highest concentration that is assured of no influence to suchextent. These concentration levels are expressed either as quantitativeratios of interferents to the target substance (e.g., 1/5, 2times)or concentrations of interferents themselves (e.g., 3%, 500ppm).Where, reads"equal to or higher than" and reads "equal to orlower than" .The presumed influence by coexistence is given in thecolumn "Interference" where the " + " sign suggests 10% or higherindication, the " - " sign expresses - 10% or lower indication, or"No"means noinfluence. "Bleaching" means that this interferent willcause the reaction colour to be pale. For your reference, thecolumn "Changes colour by itself to" is givento show how theinterferents will change the colour of the detecting layer if theyexist without the presence of the target gas. "No" represents thatno colour change will be observed. The table of this interferencegases primarily expresses the interference of each coexisting gasin the gas concentration range, equivalent to the gas concentrationby some of the other coexisting gases or vapours mentioned from themain purposes of using this detector tube. Therefore, the testresult may be given positive result by the other substance notlisted in the table. For more precise information is needed, pleasecontact us or our distributors in your territory.
Other substance (s)measurable with this detector tube	Some detector tubes have high sensitivitiesto several other substances and can be used to measure thoseconcentrations. If this is the case, the names of such substances,the correction methods of the tube readings (whether by using acorrection scale or a correction factor), the numbers of pumpstrokes and the measuring ranges are listed. For detector tubesthat perform qualitative analysis, the title of this item is readas "Substances measurable with this detector tube."
Calibration gasgeneration	The method of generating the calibrationgas that is used for calibrating the detector tube or testing itsaccuracy.
Threshold limit values andexplosive range	Some substances may behazardous to health or dangerous to life depending on theirconcentrations or the duration of exposure, or may be combustibleor explosive. For detector tubes for measuring those substances,the threshold limit values based upon the recommendations of theAmerican Conference of Governmental Industrial Hygienists (ACGIH),as well as the explosive ranges are presented for yourreference. TLV-TWA : Threshold LimitValue-Time-Weighted Average The time-weighted average concentration for a normal 8-hourworkday or 40-hour workweek, to which nearly all workers may berepeatedly exposed, day after day, without adverse effect.   TLV-STEL : Threshold LimitValue-Short-Term Exposure Limit The maximum concentration, to which workers can be exposed for aperiod of not longer than 15 minutes continuously without sufferingfrom: ( I ) irritation, ( 2 ) chronic or irreversible tissue damage, or ( 3 ) narcosis of sufficient degree to increase the likelihood ofaccidental injury, impair self-rescue, or materially reduce workefficiency, and provided that the daily TLV-TWA is notexceeded.   TLV-C : Threshold LimitValue-Ceiling The concentration that should not be exceeded during any part ofthe working exposure. In conventional industrial hygiene practiceif instantaneous monitoring is not feasible, the TLV-C can beassessed by sampling over a 15 minute period except for thosesubstances that may cause immediate irritation when exposures areshort.   Explosive range : The range of concentrations ofthe substance in which its gas or vapour mixed with air will beexplosive. Concentrations are expressed by the percentage (%) ofthe substance in the mixed air.
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