H-SEM
Introduction
Instruction 3015-4584
3
1.8 Features and Capabilities
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Detects and measures CFC, HCFC, HFC and halogen gases
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Measures all gases up to 1,000 ppm with a sensitivity of 1 ppm
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Automatically logs up to 200 gas readings that can be later be recalled for analysis
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Eliminates false alarms with use of non-dispersive IR source and sample draw system
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Visual and audible gas alarm indictors that are turned ON when the detected gas level exceeds
a user defined trip-point
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Extensive self diagnostics, providing both visual and audible indications when a fault occurs
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Battery powered, providing from 8–12 hours of operation
1.9 Functional Overview
1.9.1 General Description
The Bacharach Halogen Safe Entry Monitor (hereafter referred to as the H-SEM unit) is a portable
refrigerant gas monitor with a self contained purge-air supply. The H-SEM unit is designed to test an area
for a specific refrigerant gas for the purpose of determining the presence and level of that gas in the area
being tested.
The self contained purge-air supply allows an area to be tested for up to 40 minutes without needing to
take the monitor to an area of fresh air for zeroing purposes. The monitor self-zeros every 4 minutes to
ensure accurate gas measurements.
During normal operation the H-SEM unit displays the type of gas being monitored, along with displaying
both the current gas level and the peak gas level detected in that area on its front panel LCD. The monitor
retains a log of previous readings that can be easily accessed at a later time for analysis.
Front panel indicators and an audible alarm are provided to signal gas alarm and instrument fault
conditions. The audible alarm can temporarily be silenced by a push of a button, but will reactivate if the
gas level is still above the alarm trip point after a user defined time period has elapsed.
The H-SEM unit requires only minor periodic maintenance such as the occasional replacement of filters.
The monitor incorporates active diagnostics that continuously check the system for proper operation. A
front panel indicator is provided to alert an operator of system malfunctions, and fault codes are generated
that enable the operator to identify the cause of the fault.
1.9.2 Response to the Presence of Multiple Refrigerants
The H-SEM is a refrigerant level monitor, not a gas analyzer. You must program the monitor to test for a
specific refrigerant, and it will only return accurate concentration readings for that particular refrigerant.
When other types of refrigerant gas are present, the monitor may return incorrect readings.
Most applications only require detection of a single refrigerant and the problems that are associated with
monitoring multiple gases are rarely an issue. If there is a possibility of multiple refrigerants leaking in
the same sampling zone, then you should carefully consider which refrigerant compound you program the
unit to monitor.
