Model 9705 Process Gas / NOx Monitor

Reliable Feedback for Emissions Control

The Brand-Gaus Model 9705 is an extraordinarily compact rugged process analyzer providing fast, reliable, precise, and continuous emissions measurements of nearly any type of combustion source.

Combining the high-performance and ruggedness of solid-state chemiluminescence, UV fluorescence, and NDIR detection with our innovative patented* moderate dilution (meso-dilution) eliminates the need for climate control and most sample handling equipment found in conventional monitors. 

The Brand-Gaus Process Gas Analyzer is ideally suited for monitoring NOx or SO2 levels from feedback or feed-forward controlled processes, where very fast, real-time continuous detection is highly beneficial.

The Brand-Gaus Model 9705 Process Gas Monitor features dramatically simpler operation, lower capital and operating cost, and much higher reliability than conventional CEMS or other technologies.

Applications include:

• NOx monitoring of selective catalytic reduction systems (SCR) and non-catalytic reduction systems (SNCR)
• SO2 monitoring for SO2/SOx scrubbers
• Compliance assurance monitoring of small sources
• Emissions monitoring of combustion sources:
• Coal-fired boilers (low and high sulfur coal)
• Natural-gas fired boilers and internal combustion engines
• Diesel engines
• Gas turbines
• Nitric acid plants
• Cement kilns

Proven Field Performance

The Brand-Gaus Process NOx Analyzer achieves excellent agreement with conventional dilution-extractive CEMS on SCR outlets of coal-fired boilers, where high particulate loading and as much as 1500 PPM SO2 are present.

Simple Operation, Low Cost, High Reliability

• Patented meso-dilution fully integrates probe and analyzer flow control, greatly simplifying pneumatics and reducing parts count.
• Close-coupled measurement -- no heated sample-lines or environmental shelters required.
• Separate analyzer modules for each gas allows removal of each gas detector for ease of maintenance and repair.
• All solid-state detection: no photomultipliers, no electrochemical cells, no regeneration or switching systems, and no delicate paramagnetic components.
• Simplified pneumatics and electronics for high reliability and ease of maintenance.
• Any two gases can be measured in a single instrument

Patented Meso-Dilution Gas Analysis

Brand-Gaus's patented* meso-dilution provides fast response, robust flow control, and reliable sample extraction with far-fewer components than traditional dilution-extractive systems.

• Filtering, heating, NO2 conversion and moderate (meso) dilution of sample all occur within the process
• Eliminates any chance for condensation or precipitation while sample is extracted from the process
• Greatly simplifies pneumatics over traditional systems, integrating sample flow, ozone flow, and dilution rate control right at the probe
• Eliminates dilution eductors and fast-loop extraction components
• Sensitivity, noise, and stability greatly improved over traditional dilution systems given gas constituents are much closer to native process concentrations

High-temperature Gas Detection at the Source

Gas detector modules, ruggedized for high temperature, heavy-industrial environments, located directly at the probe

• High temperature operation allows for dilution rates as low as 5 to 1, providing superior detection performance especially at low-concentrations
• Eliminates lag time due to sample transport, achieving very fast response, ranging from 10 to 30 seconds
• Eliminates gas component losses in long sample lines
• Allows interface installation any distance from probe

Simple, Robust User Interface

Large touch screen display provides a highly intuitive interface, with fewer menus and easily adjusted operating parameters
• Simple interface for control of cal-gas and instrument air flows
• Integrated cal-check timing with choice of manual or fully automated calibration
• Sample-and-hold during cal-check
• In-cal, in-maintenance, and instrument-fault relays
• Built-in O2/CO2 correction and conversion to lbs/MMBTU
• On-screen trend chart

Gas Detection Specifications (any two gases)

	NOx	SO2	CO2	O2
Measurement technology	Chemilumin- escence	UV fluorescence	NDIR absorption	Amperometric zirconium oxide
Measurement range	0 to 1000 PPM	0 to 1000 PPM	0 to 30 %CO2	0 to 25 %O2
Zero noise	< 0.02 PPM	< 0.25 PPM	< 0.01 %CO2	< 0.02 %O2
Zero cal-drift per day	Better than ± 0.1 PPM	Better than ± 2 PPM	Better than ± 0.2 %CO2	Better than ± 0.2 %O2
Span noise	< 0.25% of reading	< 0.25% of reading	< 0.25% of reading	< 0.02 %O2
Span cal-drift per day	Better than ± 2% of reading	Better than ± 2% of reading	Better than ± 2% of reading	Better than ± 0.2 %O2
Linearity error	< 2% full scale	< 2% full scale	< 2% full scale	< 2% full scale

System Specifications

Parameter	Value
Ambient conditions	-20 to 55 C, continuous outdoor use
Power required	120 VAC, 5A max
Instrument air required	2 SCFM, 80 to 100 PSI
Sample flow	50 SCCM
Calibration flow rate	1-5 SLPM
Response Time	T95 < 15 seconds
Gas concentration signal	4 to 20 mA analog output for each gas, adjustable concentration range
Maximum process temp	500 C