Gastec 136 L Instructions

Instructions for
Methyl Bromide Detector Tube
No.136 L
FOR SAFE OPERATION :
Carefully read this manual and the instruction manual of your Gastec Gas Sampling Pump.
WARNING :
1. Use only Gastec detector tubes in a Gastec Pump.
2. Do not interchange or use non-Gastec parts or components in Gastec's detector tube and pump
system.
3. Using non-Gastec parts or components in Gastec's detector tube and pump system or using a non-
Gastec detector tube with a Gastec pump or using a Gastec detector tube with a non-Gastec pump
may damage your detector tube and pump system, or may cause serious injuries, or death to the end-
user. It will also void all warranties; and guarantees regarding performance and data accuracy.
CAUTION : If you do not observe the following precautions, you may suffer
injuries or damage the product.
1. When breaking the tube ends, keep away from eyes.
2. Do not touch the broken glass tubes, pieces and reagent with bare hand(s).
3. The sampling time represents the time necessary to draw the air sample through the tube. The tube
must be positioned in the desired sampling area for the entire sampling time or until the flow finish
indicator indicates the end of the sample.
NOTES : For maintaining performance and reliability of the test results.
1. Use Gastec Gas Sampling Pump together with Gastec Detector Tubes only for the purposes specified
in the instruction manual of the detector tube.
2. Use this tube within the temperature range of 0 - 40°C (32 - 104 ).
3. Use this tube within the relative humidity range of 0 - 90%.
4. This tube may be interfered with by the coexisting gases. Please refer to the "INTERFERENCES"
below.
5. Shelf life and storage conditions of the tube are marked on the label of the tube box.
APPLICATION OF THE TUBE :
Use this tube for the detection of Methyl Bromide in air or the industrial areas and determining the
environmental atmospheric condition.
SPECIFICATION :
(As a result of Gastec's commitment to continued improvement, specifications are subject to change
without notice)
Oxidizing Layer
Ｃ
Measuring Range 2.5 - 10 ppm
Number of Pump Strokes 4
1/4
Correction Factor
1.5 minutes per pump stroke
Sampling Time
Detecting Limit
Colour Change
Reaction Principle CH Br + I O + H S O
3 2 5 2 2
Br + o-Tolidine
→
2
Ｃ
Detecting Layer
10 - 100 ppm 100 - 200 ppm
1 1/2
1
45 seconds
0.5 ppm ( n = 4 )
White → Yellow
Br
→
7 2
Yellow Holoquinone
Coefficient of Variation : 10% (for 10 to 20 ppm), 5% (for 20 to 100 ppm)
** Shelf Life : Please refer to the Validity Date printed on the tube box.
** Store the tubes in dark and cool place.
CORRECTION FOR TEMPERATURE, HUMIDITY AND PRESSURE :
1. Temperature : No correction is required.
2. Humidity :
3. Pressure :
MEASUREMENT PROCEDURE :
1. For checking the leakage of the pump, insert a freshly sealed detector tube into the pump. Follow the
instructions provided with the pump operation manual.
2. Break the tips off a fresh primary tube and analyser tube using the tube tip breaker of the pump.
3. Connect the © marked ends with rubber tubing after snapping off each end.
4. Insert the analyser tube securely into pump inlet with the arrow
pump.
5. Make certain the pump handle is all the way in. Align the guide marks on the pump body.
6. Pull the handle all the way out until it locks at one pump stroke (100 mL). Wait 1.5 minutes and
confirm the completion of the sampling.
7. For smaller measurements less than 10 ppm, repeat the above sampling procedure three more times.
For measurements higher than 100 ppm, prepare a fresh tube and perform a half pump stroke.
8. Read concentration level at the interface where the stained reagent meets the unstained reagent.
9. If necessary, multiply the readings by the correction factors of pump stroke and atmospheric pressure.
INTERFERENCES :
Chlorine, Bromine, NOx
Saturated Halogenated Hydrocarbons
The table of this interference gases primarily expresses the interference of each coexisting gas in the
gas concentration range, equivalent to the gas concentration. Therefore, the test result may be given
positive result by the other substances not listed in the table. For more information is needed, please
contact us or our distributors in your territory
APPLICATION FOR OTHER SUBSTANCES :
Tube 136L can also be used for other substances as below:
Chlorobromomethane
1,1-Dibromoethane
1,2-Dibromoethane
Dibromomethane
Ethyl Bromide
n-Butyl Bromide
(1) Benzyl bromine
Benzyl Bromide Conc. (ppm)
Tube 136L Reading (n=1)
(2) Bromform
Bromform Conc. (ppm)
Tube 136L Reading (n=1)
2
CORRECTION FACTOR :
Detector tubes are primarily designed to measure specific gases. But it is also possible to measure
other substances of similar chemical properties with the aid of a correction factor or chart. Therefore,
please make use of the correction factor/chart measuring ranges as a reference. For more precise
factor please contact your Gastec distributor.
No correction is required.
To correct for pressure, use the formula below.
Tube Reading (ppm) × 1013 (hPa)
Atmospheric Pressure (hPa)
Substance Interference
+
+
Substance Correction Factor
1.1
0.7
0.8
0.5
1.0
1.0
10 21 46
10 20 40
1 5 10
20 40
10
on the tube pointing toward the
Interference gas only
Yellow
Yellow
No. of Pump Strokes Measuring Range
1 11 - 110 ppm
1 7 - 70 ppm
1
8 - 80 ppm
1 5 - 50 ppm
1/2, 1, 4 2.5 - 200 ppm
1 10 - 100 ppm
80 100
60 80 100
20 30 40 50
60 80
100