ENMET ISA-44-RALE-OD - Manual (Page 5)

ISA-44RALE-OD/ISA-44RAHE-OD/ISA-44E-OD ENMET Corporation
1
1.0 Introduction 1.0 Introduction
At many industrial facilities, hazards in the work atmosphere require workers to utilize respiratory air lines for protection.
Compressors usually provide the air supply for these respiratory air lines. If the compressor or the air it uses contains
carbon monoxide or is oxygen deficient, the health and safety of workers using this air are endangered. To protect the
worker from these situations, the federal Occupational Safety and Health Administration (OSHA) requires monitoring of
compressor supplied breathing air for carbon monoxide content and has established minimum oxygen requirements for
supplied respiratory air.
When respiratory air lines are located in potentially combustible atmospheres, the equipment used to monitor carbon
monoxide or oxygen deficiency must be protected so that it cannot ignite the surrounding atmosphere. For these
applications, the ISA-44RALE-OD, housed in an explosion proof enclosure, safely monitors compressed air lines of 50 -
250 psi (pounds per square inch) for both carbon monoxide (CO) and oxygen deficiency when these air lines are located
in Class I, Group C, D and Class II, Groups E, F, and G hazardous atmospheres as defined by the National Electrical
Code.
Consisting of a sampling head assembly, sensor housings and an explosion proof control unit, the ISA-44RALE-OD
monitor displays approximate CO and oxygen concentrations on separate meters, activating alarm circuitry when the
carbon monoxide content or oxygen deficiency level of compressor air reaches calibrated alarm levels. When alarm
circuitry activates, visual alarms (LED's) on the display plate of the monitor activate, indicating a potentially hazardous
level of CO or oxygen deficiency. A factory installed audio alarm (horn) is available as an option. Activating
concurrently with the visual alarms. Relay circuitry inside the ISA-44RALE-OD control unit is available to activate
auxiliary alarm systems and other equipment. All alarm circuitry automatically resets when the carbon monoxide or
oxygen deficiency hazard diminishes beyond the calibrated alarm points of the monitor.
The ISA-44RALE-OD also comes in a modified version for high pressure (300 - 5000 psi) compressed air lines. This is
the ISA-44RAHE-OD, which includes a special high pressure regulator on the sample head assembly. Except for the
high pressure regulator, operation of the ISA-44RAHE-OD is identical to that of the ISA-44RALE-OD. This manual
includes all necessary procedures for correct operation of the ISA-44RAHE-OD.
Do not use the ISA-44RALE-OD in combustible atmospheres other than Class I, Group C,D or Class II, Groups E,F
and G (as defined by the National Electrical Code). Disregarding this warning voids the instrument warranty and
initiates a situation of great potential danger to the user.
The ISA-44E-OD is an ambient air monitor.
N OTE : All specifications stated in this manual may change without notice.