RKI Instruments SDM-E2 - Manual (Page 160)

155 • Instrument Function Menu
factor for each pre-defined gas is factory defined. The factor for any user-
defined gases must be obtained through testing as described in “Obtaining a
Relative Response Factor” on page 166. Even if not all of the user-defined
catalytic combustible channels are being defined, the Factor column must have
a valid number entered. A valid number for the Factor is a value between 0.01
and 25.00.
• 1st
This column is for the low alarm point of each gas in ppm units.
• 2nd
This column is for the high alarm point of each gas in ppm units.
• Ratio
The ratio is the ppm value of the LEL for each gas. This value is specific to each
gas and can be easily determined. The maximum value it may be set to is
150,000 ppm. If an invalid number is entered, the box will turn red when the csv
file is imported back into the SDM Docking Station PC Controller Program.
NOTE: If you define a gas whose LEL is above 50,000 ppm, the %LEL reading
in Measuring Mode will reflect the defined ppm ratio, but the ppm
reading in Measuring Mode will not indicate above 50,000 ppm. For
example, if you set the ratio to be 150,000 ppm and set the catalytic
combustible channel to display the reading in ppm, the gas reading will
not indicate higher than 50,000 ppm, the equivalent of 33 %LEL and
5% volume for this ratio, but will continue to indicate %LEL readings up
to 100 %LEL and %volume readings up to 15 %volume, the equivalent
of 150,000 ppm, if the display units are changed to %LEL or %volume.
In addition, all adjustable ppm parameters cannot be set higher than
50,000 ppm.
• Volt
This value determines the sensor voltage for the catalytic combustible sensor. It
can be set to 1.3 or 2.4. When set to 1.3, the sensor is in methane elimination
mode. When set to 2.4, the sensor is reading at full response. Even if not all of
the user-defined catalytic combustible channels are being defined, the Volt
column must have a valid number entered. A valid number for the Volt column is
either 1.3 or 2.4.