51
Remarks for the table:
Linearity
The maximum deviation from the target value up to 70 %LEL (n-Nonane: up to 60 %LEL) are 11 %LEL for 1.3-Buta-
diene, 7 %LEL for Ammonia, 6 %LEL for Propylene oxide, and 6 %LEL for hydrogen (but up to 50 %LEL: 2 %LEL),
and for all the other substances listed above lower than 5 %LEL.
Column 4:
The values of the lower explosion limit in %V/V were taken from volume 1 of Brandes, E. and W. Möller: Sicher-
heitstechnische Kenngrößen, Wirtschaftsverlag NW, 2003 (ISBN 3-89701-745-8). Different lower explosion limits
may apply when setting up the devices at the place of use.
Column 5:
With the exception of Methane (detection not possible at 240 mA) and the substances Acetylene, 1.3-Butadiene,
Cyclopropane, Ethylene oxide, Propene and Propylene oxide (detection at 240 mA not investigated) the sensing
heads Polytron SE Ex PR M and SE Ex HT M shall preferably be operated with a sensor current of 240 mA, see
recommendation on page 43.
Column 7:
Application of propane with a concentration shown (in column 6) leads to the reading indicated here for the
sensing head SE Ex PR M with controller calibrated to the substance shown (in column 1).
Example: After calibration for benzene the central controller shows a reading between 40 and 61 %LEL when
0.51 %v/v propane is applied to the sensor.
The values listed are valid for new sensors and may fluctuate by ±30 %.
Missing values: Span gases with approx. 50 %LEL of the respective substance are available for these substances.
In principle, adjustment using a specific span gas will rule out a measuring error due to sensor sensitivity fluctua-
tion.
Column 8:
For Methane and Propane the first of two t
0...90
-figures relate to the test chamber procedure, all other t
0...90
-times
have been established by means of the calibration adapter procedure.
Содержание SE Ex HT M
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