Introduction & Overview; Measurement Principle; Powering Up The Sba-5; Operation - PP Systems SBA-5 Manual

Introduction & Overview

Measurement Principle

The SBA-5 OEM CO Analyzer is a non-dispersive, infrared gas analyzer that features an "Auto-
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Zero" facility. Using infrared gas analysis techniques, we can readily determine CO
Dioxide) concentrations to within a few ppm and instantaneous measurements are possible.
Gases with di-atomic molecules such as CO
CO , one region of strong absorption is 4.26 microns. A source (IR source) emitting strongly at
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this wavelength is a light bulb. If this is positioned at one end of a tube and at the other end is a
sensor that is sensitive to photons at 4.26 microns, we have a simple infrared gas analyzer. As
CO is passed down the sample cell, it absorbs some of the infrared and the sensor reading
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decreases. The "Auto-Zero" feature, which occurs at regular intervals, allows for fast warm-up,
adaptation to changing ambient conditions and excellent stability of the CO
auto-zeroing minimizes the effects on span (gas sensitivity) of sample cell contamination, source
aging, changes in detector sensitivity and changes in pre-amplifier gain. By default and after
system warm-up, the SBA-5 will perform "Auto-Zeros" every 20 minutes. The "Auto-Zero" interval
can be changed by the user if required up to a maximum of 10,000 minutes. PP Systems highly
recommends that the SBA-5 performs frequent "Auto-Zeros" to ensure accuracy and
reliability of data.
The SBA-5 features automatic temperature and pressure compensation.
The SBA-5 is supplied as a calibrated CO
type printed circuit board (PCB). All components are located on the board.

Powering up the SBA-5

The SBA-5 requires a 6-18V DC input to power up the analyzer. Power can be applied to 3
different connectors on the SBA-5 board (CN2, CN3 or CN4). See sections below for appropriate
connections.

Operation

Once the SBA-5 is connected to a proper power supply and immediately after it is powered up,
there is a short pause and then the IR source lamp starts to flash. If the RS-232 or USB line is
connected to a PC running a terminal program (i.e. Hyperterminal on older PC's and
HyperAccess on more recent PC's), the following information is transmitted:
EEPROM OK
B, SBA5,nnnn, x.xx
Where: B= Begin
nnnn= serial number
x.xx= EPROM version number
The SBA-5 temperature is checked until it stabilizes near 55
W, nn
Where: W=Warm up delay
nn= Temperature
SBA-5 CO2 Analyzer Operation Manual – Version 1.06
Introduction & Overview
strongly absorbs photons in the infrared range. For
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optical bench (to a specified range) fitted to an FR4
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signal. The action of
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o
C with the following transmitted:
(Carbon