Yokogawa In-Situ Gas Analyzer TDLS200 - Manual (Page 34)

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3.11.3 Purging Analyzer and Universal Power Supply and/or URD for Hazardous
Areas (with On-Line Validation)
• NEC/CSA Class 1, Division 2, Groups A-D
• ATEX Zone 2 CAT 3 – Dual regulators must be used on the inlet!
The block diagram below shows the sections of the analyzer that require nitrogen purging when using in
conjunction with either or the Universal Power Supply and Universal Remote Display. AZ-Type purge control
system is fi tted the Launch Unit and it includes a local indicator (Bright Green, rugged light) and pressure switch
alarm contacts (open on loss of purge pressure).
3.11.4 Purging Analyzer and Universal Power Supply and/or URD (not using On-Line Validation)
• NEC/CSA Class 1, Division 2, Groups A-D
• ATEX Zone 2 CAT 3 – Dual regulators must be used on the inlet!
The block diagram below shows the sections of the analyzer that require nitrogen purging. A Z-Type purge
control system is fi tted the Launch Unit and it includes a local indicator (Bright Green, rugged light) and
pressure switch alarm contacts (open on loss of purge pressure). The purging should be carried in sequence
typically as shown below. All purge gas connections are ¼” od Tube fi ttings.
Main
Electronic
Housing &
Purge
System
Laser
Module
Check Gas
Flow Cell
Proce
s
s
Inte
rfa
ce
Proce
s
s
Inte
rfa
ce
Detect
Module
Detect
Electronic
Housing
Nitrogen or I/A Purge
Gas Nitrogen or I/A Purge
Gas
Power
Supply
or URD
Figure 27 - Purge Flow Diagram when using on line validation
Nitrogen or I/A Purge
Gas
Check Gas
Flow Cell
Detect
Electronic
Housing
Main
Electronic
Housing &
Purge
System
Laser
Module
Check Gas
Flow Cell
Process Interface
Process Interface
Detect
Module
Detect
Electronic
Housing
Nitrogen or I/A Purge Gas
Power
Supply
or URD
Figure 28 - Purging Analyzer for Hazardous Areas -NO- On-Line Validation
Main
Electronic
Housing
& Pureg
System Detect
Electronic
Housing
Power
Supply
or URD
Check Gas
Flow Cell
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IM 11Y01B02-11E-A 5th Edition :June 5, 2012-00