Servomex SERVOPRO - Page 9

SERVOPRO NOx Analyzers Page
8
Flow System
The basic function of the flow system is to deliver highly stablized flows of sample and
air or O
2
to the ozonator and reaction chamber assemblies. The EPC (electronic
proportional control) valve delivers approximately 15 PSIG (standard without ozone
pump option) to a pre-set capillary and consequently accurately predetermines the ozone
flow rate. The air supply cylinder should be set to 25 PSIG.
Sample flows through the sample EPC valve, then the NO/NO
x
solenoid valve, then the
sample capillary and into the reaction chamber. The sample pressure is factory set to
approximately 3.85 PSIG. A close-coupled bypass capillary minimizes dead volume and
improves response time. Sample inlet pressure and regulated air pressures are monitored
by internal pressure transducers and presented in PSIG via the Diagnostics screen.
Analyzer Specifications
Specifications are subject to change without notice.
Component Specification
Detector Chemiluminescence photodiode (thermally stabilized
with Peltier cooler) detector – operating at ambient
pressure (no vacuum pump is needed).
NO, NO
2
, NOx Ranges Four operator-definable ranges from 0-3 to 0-3,000
ppm.
O2 Range
Optional Paramagnetic O2: Range 0
–
25%
Response Time
T90 < 2 seconds
at 0.6 LPM
Detection Limit
< 30 ppb
using 2x Noise
NOTE: The correct pressures are determined by the factory for optimal analyzer
performance and are recorded on the
Factory Settings Screen in the analyzer.