Sensidyne AP-20S Instruction Manual - • Slanted Stain
© 2003 Sensidyne, Inc.
11
Reading The Gas Concentration
• Slanted Stain
For direct-reading tubes, read the gas concentration from the
printed scale at the maximum end of the stain.
Two special cases are described below: Faint Discoloration and a
Slanted Stain.
For a slanted stain read the gas concentration at the middle of the
slanted layer.
Discolored Layer
Use This Reading
10
20
30
40
50
60
• Using A Conversion Chart
Align the zero end of the detecting reagent (inlet side of the tube)
with the O - O line on the concentration chart. Align the other end
of the same layer (exit side or pump side of the tube) with the X - X
line respectively. Read the gas concentration at the maximum end
of the stain against the scale on the card. If the end is slanted, read
at the middle point of the slanted stain.
X
O
100
90
80
70
60
50
25
10
5
X
O
100
90
80
70
60
50
25
10
5
Glass Analyzer
Layer
End Plug
RIGHT
Stained Analyzer
Layer
End Plug
End-of-Stain
Reading
of 62 ppm
WRONG
• Faint Discoloration (Feathering)
Discolored Layer
Use This Reading
10
20
30
40
50
60
For a faintly discolored (feathered) stain read the gas concentration
at the maximum end of the stain.