ULTRAMAT 23

The ULTRAMAT 23 is an innovative multi-component gas analyzer for measuring up to three infrared-sensitive gases using the NDIR principle. Use of a UV photometer enables you to measure even smaller concentrations of SO2 and NO2.

Measurement of oxygen (O2) is also possible through the use of electrochemical oxygen sensors or measuring cells operating according to the paramagnetic measuring principle ("dumbbell"). The use of an additional electrochemical H2S measuring cell permits use in biogas applications.

Up to four gas components can be measured continuously at the same time with the ULTRAMAT 23 gas analyzer. The device can be equipped with the following sensors:

• IR detector for IR-active gases
• UV photometer for UV-active gases
• H₂S sensor (electrochemical)
• O₂ sensor (electrochemical)
• O₂ sensor (paramagnetic)
• With the ULTRAMAT 23 gas analyzer for use in biogas plants, up to four gas components can be measured continuously: Two infrared-sensitive gases (CO₂ and CH₄), plus O₂ and H₂S with electrochemical measuring cells.
• Up to four gas components can be measured continuously using the ULTRAMAT 23 gas analyzer with paramagnetic oxygen cell: Three infrared-sensitive gases, plus O₂ ("dumbbell" measuring cell).
• With the ULTRAMAT 23 gas analyzer with UV photometer, one infrared-sensitive gas, UV-active gases (SO₂, NO₂) as well as O₂ can be measured with an electrochemical sensor.

• AUTOCAL with ambient air (depending on the measured component)
  • Highly cost-effective as calibration gases are not required
• High selectivity thanks to multi-layer detectors, e.g. low cross-sensitivity to water vapor
• Analyzer cells can be cleaned on site as required
  • Cost savings due to reuse after contamination
• Menu-assisted operation in plain text
  • No manual required for operation, high level of operator safety
• Service information and logbook
  • Preventive maintenance; help for service and maintenance personnel; cost savings
• Coded input levels protect against unauthorized access
  • Increased safety
• Open interface architecture (RS 485, RS 232, PROFIBUS, SIPROM GA)
  • Simplified process integration; remote operation and control

Special benefits when used in biogas plants

• Continuous measurement of all four key components, including H₂S
• Long service life of the H₂S sensor even at increased concentrations; no diluting or backflushing necessary
• Introduction and measurement of flammable gases as occurring in biogas plants (e.g. 70% CH₄) is permissible (German Technical Inspectorate/TÜV certificate)

• Optimization of small firing systems
• Monitoring of exhaust gas concentration from furnaces with all types of fuel (oil, gas and coal) as well as operational measurements with thermal incineration plants
• Room air monitoring
• Monitoring of air in fruit stores, greenhouses, fermenting cellars and warehouses
• Monitoring of process control functions
• Atmosphere monitoring during heat treatment of steel
• For use in non-hazardous areas

Application areas in biogas plants

• Monitoring of fermenters for generating biogas (input and pure sides)
• Monitoring of gas-driven motors (power generation)
• Monitoring of feeding of biogas into the commercial gas network

Application area of paramagnetic oxygen sensor

• Flue gas analysis
• Inerting plants
• Room air monitoring
• Medical engineering

Further applications

• Environmental protection
• Chemical plants
• Cement industry

Special versions

Separate gas paths

The ULTRAMAT 23 with 2 IR components without pump is also available with two separate gas paths. This allows the measurement of two measuring points as used e.g. for the NO_x measurement before and after the NO_x converter.
The ULTRAMAT 23 gas analyzer can be used in emission measuring devices and for process and safety monitoring.

Versions conforming to EN 14181 and EN 15267

According to EN 14181, which is standardized in the EU and required in many European countries, a QAL1 qualification test, i.e. certification of the complete measuring device including gas paths and conditioning, is required for continuous emission monitoring systems (CEMS). In accordance with EN 15267, this must be performed by an independent accredited authority. In Germany, for example, the test is performed by the German Technical Inspectorate (TÜV) and the test report is submitted to the Federal/State Workgroup for Emission Control (Bund/Länder-Arbeitsgemeinschaft für Immissionsschutz - LAI) for examination/approval. Notification is then issued by the German Federal Environment Agency (Umweltbundesamt - UBA) in the Federal Gazette (Bundesanzeiger) as well as by the German Technical Inspectorate (TÜV) here: https://www.qal1.de/en.

In the UK, the QAL1 test reports are prepared by Sira Environmental of the Environmental Agency in accordance with the MCERTS scheme and submitted for approval and publication on the SIRA Environmental websites. The other European countries rely either on the German or English certification scheme.

For use in EN 14181 applications, the devices with the article numbers 7MB235X in the Set CEM CERT (7MB1957) have undergone qualification testing according to German standards of EN 15267. These German Technical Inspectorate (TÜV) versions of ULTRAMAT are suitable for measurement of CO, NO, SO₂ and O₂ according to sections 13, 17 and 27 of the BlmSchV (Federal Emission Law of Germany) and TA Luft. Smallest measuring range tested and approved by the German Technical Inspectorate:

1 and 2-component analyzer

• CO: 0 to 50 mg/m³
• NO: 0 to 50 mg/m³
• SO₂: 0 to 70 mg/m³

3-component analyzer

• CO: 0 to 250 mg/m³
• NO: 0 to 250 mg/m³
• SO₂: 0 to 70 mg/m³

Also tested as additional measuring ranges in accordance with EN 15267-3:

• CO: 0 to 1 250 mg/m³
• NO: 0 to 2 000 mg/m³
• SO₂: 0 to 7 000 mg/m³

Determination of the analyzer drift according to EN 14181 (QAL3) can be carried out manually or also with a PC using the SIPROM GA maintenance and servicing software. In addition, selected manufacturers of emission evaluation computers offer the possibility to read the drift data via the analyzer's serial interface and automatically record and process it in the evaluation computer. For devices in applications requiring a certified measuring range of less than 0 ... 100 mg/m³, compensation of the CO₂ cross-interference for CO and NO and of the O₂ cross-interference for NO is necessary.

Version with faster response time

The connection between the two condensation traps is equipped with a stopper to lead the complete flow through the measuring cell (otherwise only 1/3 of the flow), i.e. the response time is 2/3 faster. The functions of all other components remain unchanged.

Chopper purge

Consumption 100 ml/min (upstream pressure setting: approx. 3 000 hPa).

• 19" rack unit with 4 U for installation
  • In hinged frame
  • In cabinets
• Flow indicator for sample gas on front plate;
  option: integrated sample gas pump (standard for bench-top version)
• Gas connections for sample gas inlet and outlet as well as zero gas; pipe diameter 6 mm or ¼"
• Gas and electrical connections at the rear of the device (portable version: sample gas inlet at front)

Display and operator panel

• Operation based on NAMUR recommendation
• Simple, fast parameterization and commissioning of analyzer
• Large, backlit LCD for measured values
• Menu-driven operator functions for parameterization, test functions and calibration
• Washable membrane keyboard
• User help in plain text
• 6-language operating software

Inputs/outputs

• Three digital inputs for sample gas pump On/Off, triggering of AUTOCAL and synchronization of several devices
• Eight relay outputs can be freely configured for fault, maintenance demanded, maintenance switch, limits, measuring range identification and external solenoid valves
• Eight additional digital inputs and relay outputs as an option
• Electrically isolated analog outputs

Communication

RS 485 present in basic unit (connection from the rear).

Options

• RS 485/RS 232 converter
• RS 485/Ethernet converter
• RS 485/USB converter
• Incorporation in networks via PROFIBUS DP/PA interface
• SIPROM GA software as service and maintenance tool

ULTRAMAT 23, membrane keyboard and graphic display

ULTRAMAT 23, design

Gas path

ULTRAMAT 23, portable, in sheet-steel housing with internal sample gas pump, condensation trap with safety filter on front plate, optional oxygen measurement

ULTRAMAT 23, 19" rack-mounted enclosure with internal sample gas pump; optional oxygen measurement

ULTRAMAT 23, 19" rack-mounted enclosure without internal sample gas pump; optional oxygen measurement

ULTRAMAT 23, 19" rack unit housing without internal sample gas pump, with separate gas path for the 2nd measured component or for the 2nd and 3rd measured component, optional oxygen measurement

ULTRAMAT 23, 19" rack-mounted enclosure, sample gas path version in pipes, separate gas path, always without sample gas pump, without safety filter and without safety condensation trap

ULTRAMAT 23, 19" rack-mounted enclosure with internal sample gas pump and H₂S sensor

ULTRAMAT 23, 19" rack-mounted enclosure with internal sample gas pump and paramagnetic oxygen measurement

ULTRAMAT 23, 19" rack unit enclosure with IR detector, UV photometer (UV module); optional oxygen measurement

ULTRAMAT 23, 19" rack-mounted enclosure with UV photometer (UV module); optional oxygen measurement

The ULTRAMAT 23 uses multiple independent measuring principles which work selectively.

Infrared measurement

The measuring principle of the ULTRAMAT 23 is based on the molecule-specific absorption of bands of infrared radiation, which in turn is based on the "single-beam procedure". A radiation source (7) operating at 600 °C emits infrared radiation, which is then modulated by a chopper (5) at 8 1/3 Hz.

The IR radiation passes through the sample chamber (4), into which sample gas is flowing, and its intensity is weakened as a function of the concentration of the measured component.

The detector chamber - set up as a two- or three-layer detector chamber - is filled with the component to be measured.

The first detector layer (11) primarily absorbs energy from the central sections of the sample gas IR bands. Energy from the peripheral sections of the bands is absorbed by the second (2) and third (12) detector layers.

The microflow sensor generates a pneumatic connection between the upper layer and the lower layers. Negative feedback from the upper and lower layers leads to an overall narrowing of the spectral sensitivity band. The volume of the third layer and, therefore, the absorption of the bands, can be varied using a "slide switch" (10), thereby increasing the selectivity of each individual measurement.

The rotating chopper (5) generates a pulsating flow in the detector chamber that the microflow sensor (3) converts into an electrical signal.

The microflow sensor consists of two nickel-plated grids heated to approximately 120 ºC, which, along with two supplementary resistors, form a Wheatstone bridge. The pulsating flow together with the dense arrangement of the Ni grids causes a change in resistance. This leads to an offset in the bridge, which is dependent on the concentration of the sample gas.

Note

The sample gases must be fed into the analyzers free of dust. Condensation in the sample chambers must be prevented. Therefore, the use of gas modified for the measuring task is necessary in most application cases.

As far as possible, the ambient air of the analyzer unit should also not have a large concentration of the gas components to be measured.

ULTRAMAT 23, mode of operation of the infrared channel (example with three-layer detector)

Automatic calibration with air (AUTOCAL)

The ULTRAMAT 23 can be calibrated using, for example, ambient air. During this process (adjustable between 1 and 24 hours, 0 = no AUTOCAL), the chamber is purged with air. The detector then generates the largest signal U₀ (no pre-absorption in the sample chamber). This signal is used as the reference signal for zero point calibration, and also serves as the initial value for calculating the full-scale value in the manner described below.

As the concentration of the measured component increases, so too does absorption in the sample chamber. As a result of this pre-absorption, the detectable radiation energy in the detector decreases, and thus also the signal voltage. For the single-beam procedure of the ULTRAMAT 23, the mathematical relationship between the concentration of the measured component and the measured voltage can be approximately expressed as the following exponential function:

U = U₀ · e^-kc

Changes in the radiation power, contamination of the sample chamber, or aging of the detector components have the same effect on both U₀ and U, and result in the following:

U’ = U’₀ · e^-kc

Apart from being dependent on concentration c, the measured voltage thus changes continuously as the IR source ages, or with persistent contamination.

Each AUTOCAL thus tracks the total characteristic curve according to the currently valid value. Temperature and pressure influences are also compensated in this way.

The influences of contamination and aging, as mentioned above, have a negligible influence on the measurement as long as U’ remains in a certain tolerance range monitored by the device.

The tolerance range between two or more AUTOCALs can be individually configured on the ULTRAMAT 23 and an alarm message output. An alarm message is output when the value falls below the original factory setting of U₀ < 50% U. In most cases, this is due to the sample chamber being contaminated.

Calibration

The devices can be set to automatically calibrate the zero point every 1 to 24 hours, using ambient air or nitrogen. The calibration point for the IR-sensitive components is calculated mathematically from the newly determined U’_o and the device-specific parameters stored as default values. We recommend checking the calibration point once a year using a calibration gas. (For details on German Technical Inspectorate/TÜV measurements, see Table "Calibration intervals (TÜV versions)" under Selection and ordering data).

If an electrochemical sensor is installed, it is recommendable to use air for the AUTOCAL. In addition to calibration of the zero point of the IR-sensitive components, it is then also possible to simultaneously calibrate the calibration point of the electrochemical O₂ sensor automatically. The characteristic curve of the O₂ sensor is sufficiently stable following the single-point calibration. The zero point of the electrochemical sensor only needs be checked once a year by connecting nitrogen.

Calibration

Ultraviolet measurement

ULTRAMAT 23, ultraviolet measurement mode of operation

This measuring principle is also based on the molecule-specific absorption of bands of ultraviolet radiation using a double-beam photometer.

The light source is a solid-state diode (LED) based on AlGaN or InGaN semiconductors (1). To improve the signal evaluation, the light source is operated as a pulsed light source.

The ultraviolet radiation is collimated and first passes through a beam splitter (3), which generates two identically sized ray bundles (measuring and reference radiation). The measuring ray bundle passes through the sample chamber (6) into which the sample gas is flowing, and is attenuated as a function of the concentration of the measured component. This attenuation is evaluated according to the Lambert-Beer absorption law.

The measuring radiation is recorded by a photodiode (4) downstream of the sample chamber into which the sample gas is flowing (measuring signal). Likewise, the reference radiation is recorded by a second photodiode (5, reference signal). The ratio of measured signal and reference signal is used to calculate the concentration of the gas component.

The beam splitter also enables the coupling of a second light source (2) for measuring a second gas component. In this way, the absorption of sulfur dioxide (SO₂) and nitrogen dioxide (NO₂) is measured in alternating cycles and converted into continuous concentration values in sensor-level electronics. Additional sample gas applications are possible through a suitable selection of LEDs.

Oxygen measurement

The oxygen sensor operates according to the principle of a fuel cell. The oxygen is converted at the boundary layer between the cathode and electrolyte. An electron emission current flows between the lead anode and cathode and via a resistance, where a measured voltage is present. This measured voltage is proportional to the concentration of oxygen in the sample gas.

The oxygen electrolyte used is less influenced by interference influences (particularly CO₂, CO, H₂ and CH₄) than other sensor types.

Note

The oxygen sensor can be used for concentrations of both > 1% and < 1% O₂. In the event of sudden changes from high concentrations to low concentrations (< 1%), the sensor will, however, require longer running-in times to get a constant measured value. This is to be taken into consideration when switching between measuring points in particular, and appropriate purging times are to be set.

ULTRAMAT 23, oxygen sensor mode of operation

Electrochemical sensor for H₂S determination

The hydrogen sulfide enters through the diffusion barrier (gas diaphragm) into the sensor and is oxidized at the working electrode. A reaction in the form of a reduction of atmospheric oxygen takes place on the counter electrode. The transfer of electrons can be tapped on the connector pins as a current which is directly proportional to the gas concentration.

Calibration

The zero point is automatically recalibrated by the AUTOCAL function when connecting e.g. nitrogen or air. It is recommendable to check the calibration point monthly using calibration gas (45 to 50 vpm).

The AUTOCAL (with ambient air, for example) must be performed every hour. In so doing, you must ensure that the ambient air is saturated in accordance with a dew point of 11 °C.

If this cannot be constantly ensured with dry ambient air, the adjustment gas must be fed through a humidifier and subsequently through a cooler (dew point 11 °C).

If the accompanying gas contains the following components, the hydrogen sulfide sensor must not be used:

• Compounds containing chlorine
• Compounds containing fluorine
• Heavy metals
• Aerosols
• Alkaline components
• NH₃ > 5 vpm

Operating principle of the H₂S sensor

Paramagnetic oxygen cell

In contrast to other gases, oxygen is highly paramagnetic. This property is used as the basis for the method of measurement.

Two permanent magnets generate an inhomogeneous magnetic field in the measuring cell. If oxygen molecules flow into the measuring cell (1), they are drawn into the magnetic field. This results in the two diamagnetic hollow spheres (2) being displaced out of the magnetic field. This rotary motion is recorded optically, and serves as the input variable for control of a compensation flow. This generates a torque opposite to the rotary motion around the two hollow spheres by means of a wire loop (3). The compensation current is proportional to the concentration of oxygen.

Calibration

The calibration point is calibrated with the AUTOCAL function when processing air (corresponding to calibration with the electrochemical O₂ sensor). In order to comply with the technical data, the zero point of the paramagnetic measuring cell must be calibrated with nitrogen weekly in the case of measuring ranges < 5% or every two months in the case of larger measuring ranges.

Alternatively, inert gases (such as nitrogen) can be used for AUTOCAL. As the limit point of the measuring range remains largely stable, an annual limit point adjustment will suffice.

Operating principle of the paramagnetic oxygen cell

Cross-interferences, paramagnetic oxygen cells

Cross-sensitivities (with accompanying gas concentration 100%)

Main features

• Practically maintenance-free thanks to AUTOCAL with ambient air (or with N₂, only for devices without an oxygen sensor); both the zero point and the sensitivity are calibrated in the process
• Calibration with calibration gas only required every twelve months, depending on the application
• Two measuring ranges per component can be set within specified limits; all measuring ranges linearized; autoranging with measuring range identification
• Automatic correction of variations in atmospheric pressure
• Sample gas flow monitoring; error message output if flow < 1 l/min (only with Viton sample gas path)
• Maintenance demanded
• Two freely configurable undershooting or overshooting limits per measured component