Appendix E Detecting Other Gases - Emerson Rosemount 625IR Manual

Manual
MS-00809-0100-3625
E Detecting other gases
Emerson calibrates the Rosemount 625IR and 625IR Duct for specific gases, but they are
also sensitive to other specific gases. This is important to consider to avoid false alarms,
but it can also be very useful to detect other hazardous gases.
For example, a 625IR propane detector will also measure butane, isobutane, ether, and
isopentane with very similar gas readings, so the same alarm levels should also be
applicable for these gases. Other gases can react more strongly or weakly and must be
accounted for. For example, methanol will measure very strongly on a propane detector,
so you might consider a higher alarm level, while xylene has a weaker response, so you
should use a lower alarm level.
will detect. Contact your vendor for more details on these and other gases.
Table E-1: Gas detection levels
Investigated gas (CAS
number)
Butane (106-97-8)
Isobutane (75-28-5)
1,3 butadiene (106-99-0)
1-butene (25167-67-3)
Dimethylamine (124-40-3)
Diethyl ether (60-29-7)
Ethane (74-84-0)
Ethanol (64-17-5)
Ethene (74-85-1)
Ethylene oxide (75-21-8)
Hexane (110-54-3)
Isopropylamine (75-31-0)
Methane (74-82-8)
Methanol (67-56-1)
Ethylamine (75-04-7)
Pentane (109-66-0)
Isopentane (78-78-4)
Propane (74-98-6)
Propene (115-07-01)
Xylene (108-38-3)
Rosemount 625IR
Table E-1
Type of response in the detector
Similar level
(recommended detector)
625IR propane
625IR propane
625IR propane
625IR propane
625IR propane
625IR propane
625IR propane
625IR propane
N/A
N/A
625IR propane
625IR propane
625IR methane
625IR propane
625IR propane
625IR propane
625IR propane
625IR propane
N/A
N/A
is an overview of some gases that the detector
Very strong and non-linear
625IR methane
625IR methane
625IR methane
625IR methane
625IR methane
625IR methane
625IR methane
625IR methane
N/A
625IR methane
625IR methane
625IR methane
N/A
625IR methane
625IR methane
625IR methane
625IR methane
625IR methane
625IR methane
625IR methane
Detecting other gases
January 2024
Weak detection (< 40%
response)
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
625IR propane
625IR methane
625IR propane
N/A
N/A
625IR propane
N/A
N/A
N/A
N/A
N/A
625IR propane
625IR propane
67