6. When this extension hose is used, sampling time may be different from the instruction manual of detector
tube. Also, correction factor may have to be applied to tube reading. (See below chart for sampling time
and correction factor.) As necessary, multiply the correction factors of temperature, humidity, pump
strokes, extension hose, and atomospheric pressure.(When measuring a gas listed on “APPLICATION
FOR OTHER SUBSTANCES”in the instruction manual, apply the correction factor/scale after these
corrections.) Refer to the instruction manual of your Gastec Gas Detector tube for temperature, humidity,
and pump strokes correction.
Sampling time and correction factors for No.351A-30
(Sampling times are approximate value.)
Currently only the detector tubes listed below are applicable to No. 351A-30. If you need to use other
tube, please contact your Gastec representatives.
Tube No.
Gas or Vapour to be Measured
Sampling time
for 1 pump
stroke
（
100mL
）
Sampling time for a
half pump stroke
（
50mL
）
Correction factor
1L
Carbon monoxide
1.5min.
45sec.
1.13
1LK
Carbon monoxide
3min.
1.5min.
NONE
1LL
Carbon monoxide
3min.
1.14
2HH
Carbon dioxide
2min.
1min.
1.12
2H
Carbon dioxide
1min.
30sec.
1.12
2L
Carbon dioxide
3min.
1.5min.
NONE
2LC
Carbon dioxide
3min.
1.5min.
NONE
2LL
Carbon dioxide
2min.
NONE
3M
Ammonia
1.5min.
45sec.
NONE
3L
Ammonia
1min.
30sec.
1.11
3La
Ammonia
45sec.
30sec.
NONE
4HM
Hydrogen sulphide
1.5min.
45sec.
NONE
4HH
Hydrogen sulphide
1min.
30sec.
NONE
4M
Hydrogen sulphide
1.5min.
45sec.
NONE
4H
Hydrogen sulphide
1min.
30sec.
NONE
4L
Hydrogen sulphide
1.5min.
45sec.
NONE
4LL
Hydrogen sulphide
1min.
30sec.
NONE
4LK
Hydrogen sulphide
1min.
30sec.
NONE
4LB
Hydrogen sulphide
1min.
30sec.
NONE
4LT
Hydrogen sulphide
1.5min.
45sec.
NONE
5La
Sulphur dioxide
1min.
NONE
5Lb
Sulphur dioxide
1min.
1.12
5LC
Sulphur dioxide
3min.
NONE
6L
Water vapour
30sec.
30sec.
NONE
7H
Phosphine
1min.
30sec.
NONE
7J
Phosphine
1min.
30sec.
1.29
7
Phosphine
1.5min.
NONE
7LA
Phosphine
1.5min.
NONE
7L
Phosphine
1.5min.
NONE
9L
Nitrogen dioxide
1min.
1.60
11L
Nitrogen oxides
2min.
1.35
15L
Nitric acid
45sec.
30sec.
1.33
19La
Arsine
2min.
NONE
30
Hydrogen
3min.
NONE
35
Sulphuric acid
1.5min.
NONE
40
Mercury vapour
2min.
1min.
1.20
60
Phenol
2min.
1min.
1.12
70
Mercaptans
2min.
NONE
