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DC-ITD-FTIR-MAN01
www.dodtec.com
FEB 2020
815-788-5200
FTIR Manual
Chapter 1
–
Overview
1.1 Introduction
The DOD Technologies DOD64-FTIR can sequentially monitor 16 to 64 locations (called sample points) and is
designed for fast and accurate multi-sequential analysis of a variety of gases. The DOD64-FTIR incorporates
Fourier Transform Infrared gas detection technology to detect low levels of many Infrared active gases.
Sample points can be placed up to 400 ft. (121 m) from the central unit, allowing operators to monitor gas
concentrations in areas removed from the
detector’s
location. A sample from each point is drawn to the
central location of the monitor via tubing and analyzed for toxic, corrosive and flammable gases based on the
applications requirements. Contact DOD for specific gas calibration details or for interest in specific
calibration requirements which may require a development partnership.
The DOD64-FTIR system can be configured with a maximum of 4 manifolds and each manifold has 16
sample points. Gas detection and analysis occurs in the DOD64’s Interferometer located above the pump
panel within the service door. Sample activity, data collection and corresponding output action occurs in the
DOD64-FTIR onboard PC located in the control box.
The system responds to gases that exceed a programable alarm level or a system fault by:
•
Triggering outputs or communication method installed on the unit.
• Displaying the point number, gas type, and gas concentrations
in red.
• Electronically storing Alarms, Concentrations, Spectra
data, and History.
The DOD64-FTIR triggers outputs for each individual point at two levels of gas concentrations. These
programmable limits are selectable and have default factory settings for their respective gas ranges. The
DOD64-FTIR is designed for maximum uptime, so routine maintenance and service can be performed quickly
and easily. The DOD64-FTIR uses FTIR technology which includes an interferometer with either MCT Sterling
cooled detector or a DTGS detector. The preferred detector type should be specified at the time of purchase.
1.2 Sampling and Analyzing
The DOD64 FTIR extracts a sample continuously from each point to reduce sample transport time. Reduction
in transport time is achieved with one dedicated transport pump per 16 sampling locations continuously
pulling a sample. There is also one independent analysis pump which draws the sample line intended to be
analyzed through the DOD64-
FTIR’s sampling cell
after the individual point valve is opened. The DOD64-FTIR
also allows for continuous sampling of a single loc
ation through the “lock on point feature”
.
1.3 Nitrogen Purging
Nitrogen purging is a critical to the operation of the DOD64-FTIR. Nitrogen is used to perform periodic
background checks to eliminate detector output drift due to humidity and temperature shifts that can occur in
different environments. The Nitrogen background function also assist in the correction of changes that occur
naturally within the interferometer. These background checks can be initiated manually or can be set to occur
automatically at user-defined time intervals.
The nitrogen supply connection is located on the right-hand side of the machine, in the upper left corner. If
the system is located in an enclosed area, be sure to take all the safety requirements necessary in the use of
nitrogen, which may include monitoring for loss of oxygen in this area. Contact DOD Technologies for
additional oxygen deficiency monitoring if needed.
