Imtroduction

The analyzer is housed in a steel 19” rack 3 vertical unit high.

 

On the rear panel are located the connector for digital and analogical input and output, the filtered power connect with switch and fuses and the fittings for sample inlet and outlet. Inside the housing is located a low flow detector and optionally a diaphragm pump and an AISI solenoid valve for automatic zero calibration and an electrochemical cell for the O2 simultaneously measure in the sample.

 

In the front panel are present a 16 keys keyboard, a fast to be check and replace fine filter with the big back lighted LCD display

 

Application

The analyzer can be used for gas measuring in a wild range of industrial applications:

 Combustion control

Measuring of emissions of boilers, furnaces, domestic and industrial incinerators, cement,  furnaces, etc.

 

Process gas

Monitoring of emissions from engines and turbine with NOx lowering systems (SCR – DENOX – LENOX etc…)

Analysis of gases from

Air quality in green houses, tunnels, parking

Analysis of protection atmosphere

Principle of operation

 

A wide band infrared radiation is emitted by a non metallic, high stability source.

 

For each measured gas this radiation is brought alternatively through an interferential filter and a filter with a glass cell (GFC) filled with high partial pressure of the gas to be analyzed.

A suitable optical system drives the IR radiation inside the analysis chamber and then to the detector which receives and amplifies alternatively the two signals: one is the measure, the other is the reference. The gas concentration is proportional to the difference of the two signals.

 

Gases which may have a cross sensitivity with the measured gas, generate the same variation of the measure and reference signals. Therefore the measure is not affected.

 

Technical description

The Enox multigas analyzer is an industrial photometer based on the non dispersive photometry in the infrared, for the contemporary measure of several gases.

 

The main feature of this enhanced analyzer model DPB (double path beam) is to have a long optical path to obtain to very high sensitivity to guarantee the declared performance even on the very low ranges requested from the lower and lower emissions limit  imposed.

 

The mainly pulse to follow and reach this solution has been driven from the necessity to develop an NDIR NO (nitrogen oxide) analyzer with performance comparable with the expensive ones normally used where the emission limits are about some tens vpm. 

 

The technology which has been used is based on correlation filters (GCF) and optical non dispersive absorption (DOAS). A high stability sensor, working at a very low temperature (-35 °C) and the GFC technology ensure a nearly fully immunity to cross sensitivity, high stability and sensitivity.

 

The measuring principle, the optical bench and the automatic and accurate compensation of the variations of room temperature enable to avoid the expensive and complicated automatic calibrations, which are always possible.

 

A large back lighted graphic display continuously supplies the value of the measured gases (including a large bar graph), the alarms, the service requirements, the faults, separated for each gas and the alarms from the sampling system. All alarms have the acknowledgement routine. All anomaly messages are reported on the display for the immediate knowledge of what has gone wrong. Relays contacts enable all the diagnostic to be retransmitted.

 

This instrument has been drawn to be user friendly and reduce as much as possible the costs of the analysis system in which it will be used. The analyzer can manage a multiplexing CEM up to four emission point and can be directly connected to a P.C. provided with a special software, named DAS-DAC, for data acquisition monitoring and reporting..

 

Technical specifications
Measured components	Lowest ranges: 1.                CO    0…10   ppm  2.                CO2  0…10   ppm  3.                NO    0…50   ppm  4.                SO2  0…400 ppm  5.                CH4  0…100   ppm  6.                O2    0…25% in volume Highest ranges:        100% or saturation.
Measure units	vpm, mg/m3, mg/Nm3, %
Display	240X128 pixel, graphic, back lighted LCD, tunable contrast
Keyboard	16 keys membrane
Analogical Output	N. 4      4-20 mA linear isolated. Max load 500 ohm.
Digital Output	RS 232, RS 485,  Modbus
Flow control on sample	Continuous on flow lower than  0.5 l/min
Digital Output	N. 2  contacts settable alarms on each measure, except oxygen  N. 1  contact service for each measure, except oxygen N. 1  contact fault for each measure, except oxygen, and    flow fault N. 1  contact for calibration  N. 2  contacts for solenoid valve, in case of external calibration (24 Vcc 50 mA)
Digital Input (12 Vcc 100 mA)	N. 1  Distant calibration  N. 1  sampling system fault  N. 4  stack currently on measure (for scansions) N. 4  low cylinder pressure
Warm up time	’15   45’ best performance
Zero calibration.	Automatic with ambient air or nitrogen. Tunable frequency and duration
Span calibration	Automatic not necessary. Tunable frequency and duration
Drift	Negligible with automatic zero calibration: ·         < 2% of lowest range without automatic zero calibration ·         Ambient temperature: negligible continuously compensated ·         Atmospheric pressure: settable  ·         zero: none  ·         span about 1% of measured value for 1% of atmospheric   pressure change
Response time    (T90)	Depending on mobile average set
Noise	</= 1% of lowest range
Mobile average	Tunable between 0 ….600”
Ambient temperature	For measure +5…+35°C For stocking and transport -10…+55°C
Moisture	<90% RH not condensing
Panel filter	Retention: 1 micron
Sample gas status	pressure      20…80 mbar  flow          30…180 Nl/h  temperature +5…+50°C  dew point   at least 5°C under ambient temperature
Protection	IP20
Power	115-230 V AC +/-10% about 70 VA
Dimensions	450X132x380 mm
Weight	kg. 12