Chemgard Infrared Gas Monitor
Section 1, General Information
•
Each point is capable of sampling from
remote areas up to 500 feet (152 m)
from the Chemgard unit
•
Contains all necessary flow components
(excluding end-of-line filter and sampling line)
to properly sample four or eight areas and
indicate the gas or vapor concentrations.
Terminology
Become familiar with the following terminology.
ZERO- A zero (0) indication on the meter
display usually indicates fresh air (no gas present).
ZEROING- The process of placing a zero gas on
the unit during calibration.
SPAN- Full-scale or up-scale reading on
meter display.
SPANNING-
The process of placing a full-scale or
span gas on the unit during calibration.
SPAN GAS VALUE- The gas concentration that
gives the instrument a full-scale or up-scale value.
This value is printed on the calibration gas
cylinder containing the gas.
FLOW RATE- Volume of gas drawn through the
sample line per minute.
EXHAUST GAS- Sample gas after it passes
through the sensor.
PUMP- The electric motor driven device that
moves the gas sample to the Chemgard Monitor.
ALARMS- The Chemgard System has three alarms
to alert the
user at specific, user-adjustable gas
concentrations. (Level 1 = Caution,
Level 2 = Warning and Level 3 = Alarm.)
RELATIVE HUMIDITY- The percent of water vapor
saturation in air at a given temperature.
POINT NUMBER- The location or area from which
a gas sample is drawn. Up to four or eight areas,
sequentially numbered from 1 to 8, can
be sampled.
BYPASS- The Sequencer is a look-ahead system;
bypass gas flow is drawn from the next area to
be sampled. This feature reduces the monitor
response
time when long sampling lines are used.
FRESH AIR- Air that has no possibility of
containing gas.
TEMPERATURE EFFECT- The gas response
displayed by the instrument (PPM) can change
±0.3% for each degree (C) that the instrument is
operating above/below the temperature at which
the instrument was last calibrated.
Applications
The Chemgard Monitor is factory-calibrated for a
particular gas. When calibrated, the Chemgard
System is used in a wide variety of industrial
applications, such as:
•
detection of gases leaking into the atmosphere
•
ambient air monitoring for health and
safety purposes
Sensor Selectivity*
The Chemgard Gas Monitor is factory-calibrated
for your particular gas (TABLE 1-3). The system
is highly selective to gases in air; however, the
system also responds to other gases
(interferants). See TABLES 1-2 through 1-22* for
typical cross-sensitivities. Actual cross-sensitivities
vary from instrument to instrument.
If it is not known whether the gas to be detected
is an interferant gas, contact MSA at:
1-800-MSA-INST.
*Typical cross-sensitivities not verified or investigated by UL.
To Next Page
Loading...
