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Ozone gas is used for cleaning,
purifying and other purposes in many
industrial hygiene applications. At low
levels, ozone gas is harmless and present
in the air we breathe every day. At higher
levels, ozone can negatively affect human
health. Protecting people in the workplace
is always a top priority, so monitoring ozone
applications for leaks is imperative. The
preferred method of monitoring for harmful
ozone exposure is to use the Teledyne API
(TAPI) 480L UV photometric ozone monitor.
The 480L is an extremely stable
analyzer that is ideal for critical low-level
ppm safety and process applications. In
applications where ozone gas is used in
multiple locations, the 480L has optional 3
and 6 channel versions available.
Multi-channel Stream Selector Option
The 480L multi-channel stream selector
option gives the user the ability to monitor
up to 3 or 6 different locations with one
instrument. This allows for a couple of
advantages: cost-savings and simplifying
communications if the instrument is
reporting back to a PC or other external
device. Some unique features of the 480L
multi-channel stream selector option are the
ability to program individual dwell times and
specific alarm settings for each channel.
This programming is easily done from the
front panel of the instrument from a userfriendly graphical interface, with no
potentiometer or blind adjustments required.
Individual Channel Settings
The 480L multi-channel stream selector
option provides the ability to program each
of the 3 or 6 channels independently,
making it possible to efficiently monitor all
channels. The user can program different
sample time durations for each channel,
from 60 to 360 seconds, from the front
panel. This feature is very handy to
compensate for sample locations varying in
distance from the 480L. If a channel doesn’t need to be monitored, then the user
can disable it through the front panel
interface.
The Model 480L can also provide
warning signals in case ozone levels are
close to or above safe exposure limits. ‘Hi’
and ‘Hi-Hi’ alarms for two levels of safety
alerts can be programmed from the front
panel. Each channel’s alarm threshold is
programmed individually and can be
anywhere from 0.01 to 1000 ppm. The
status of these alarms is available via the
graphical display. Note that the alarms
default to a ‘latching’ state, meaning they
will not automatically reset when the alarm
condition is removed. Changing the setting
to ‘non-latching’ allows the 480L to reset the
alarm state as soon as the alarmed channel
is sampled with an ozone level below the
alarm set point.
Understanding the Channel Alarm
Relays
The 480L alarms are extremely
important as they indicate potentially
dangerous levels of ozone for people. For
the multichannel version, each channel has
its own set of 3 isolated output signals. You
can find a description of each in Table 1. Signal #1, for stream ID, will activate
anytime that stream is being sampled.
Signal #2 and #3 will activate if the ozone
concentration for a stream exceeds the Hi
or Hi-Hi alarm setting.
Global status relays are also available
when using the multi-channel stream option.
Table 2 shows the description for these
relays. These can be used to notify
someone or something that an alarm
condition is occurring on one of the
channels or that all channels are OK.
These are especially useful when a general
or global alert is needed to cover all
channels.
Remember that the alarms in the Model
480L are set by default to ‘latching.’ The
alarm must be reset manually by
acknowledging and resetting the alarm on
the front panel. The alarm cannot be reset if
the ozone reading for that channel, or all
channels for the global alarms, has not come down below the alarm set point.
Non-latching alarms will automatically reset
when the alarm condition is removed.
Conclusion
TAPI’s 480L with the multi-channel
stream selector option is designed to be
easily set up and customized for each
application. Independent channel settings
for sample duration times and alarm
threshold settings allow the user to optimize
the 480L for their application conveniently
from the front panel. Multiple status
outputs, relays and digital communication
options help ensure clear communication of
an issue and ultimately a safer workplace.
For more information, documentation
and related software, please visit the 480L
product page on the TAPI website at:
www.teledyne-api.com/products/processozone-instruments/480l or contact our sales
team at: [email protected].
