SIRA device for measuring odorant concentration

SIRA ODOR Messgerät Odormittelkonzentrationen Oberteil


Natural gases and hydrogen are by nature low in odor or even odorless to humans.

In order for potential leaks to be noticed and eliminated in a timely manner thanks to someone smelling the typical gas odor, these gases are supplemented with an odorant (i.e. odorized) in the gas grid.

A new process gas analyzer uses UV spectrometry for the legally required odorization check.


Product flyer (PDF)



Product video




Dimensions H=990 mm/W=360 mm/D=300 mm
aluminium housing
Weight approx. 30 kg
IP classification IP42
Operating temperature -10°C to +50°C
-20°C to +60°C (customized)
Umgebungsfeuchtigkeit max. 95 % relative humidity,
Mounting wall mounting,
including wall holders
Ventilation 2x active ventilation
Power supply 110-230 VAC
50-60 Hz
200 W
Fault relay 24 VAC/100 mA
Service relay 24 VAC/100 mA
Communication options 0/4 – 20 mA
digital output
fieldbus systems
Display/operation 10.2" Touchscreen display
Hardware multiprocessor system with 32 GB storage
Software Embedded Linux operating system
Safety monitoring ventilation function
pressure monitoring
flow monitoring
Gas inlet process gas
calibration gas
test gas
Gas connection 6 mm stainless steel compression fitting
Gas outlet flue gas
Gas connection 6 mm stainless steel compression fitting
Process gases H-/L-gases
Ambient pressure range 950 – 1,100 mbar
Gas pressure 20 – 50 mbar
Gas consumption max. 20 l/hr.


Adapted analyzer systems are available for the relevant odorants. The central assembly of the analyzer system is the UV sensor in conjunction with a zero gas generation system matched to the odorant.

Adaptation of the analyzer system in the event of a change of odorant is possible at any time.

OdorantMeasuring rangeError limits
Tetrahydrothiophene (THT) 0 – 50 mg/m³  0.75 mg/m³ or 10 % of the measured value
Gasodor® S-Free 0 – 50 mg/m³ 0.75 mg/m³ or 10 % of the measured value


SIRA ODOR Messgerät Odormittelkonzentrationen Display

Configurable parameters

  • adjustment of different parameters according to users’ needs, e.g. measurement cycles, units, storage intervals, views, reports

Control concept dependent on access rights

  • access rights via user level
  • configurability and transmission of measurement data and reports


Cycled measurement from 120 seconds to 24 hours

  • setting of measuring cycles
  • saving of measurement results
  • history with graphic display
  • protecting the setting of measuring cycles

Automatic reporting

  • generating reports from the saved measurements (duration of reporting periods can be adjusted freely)

Export function of measurement data

  • saving measurements and reports on the device, including exporting

Uploading data in the cloud

  • accessing measurements and reports on a file server via the internet

Remote monitoring (remote maintenance possible)

  • retrieval of measurements and the resulting graphs
  • setting of measurement cycles and export of measurement data and reports

GSM connectivity

  • dispatch of alarm emails or SMS messages to preset destinations when threshold values exceed or fall below the set limits (the email or SMS indicates the device and the reason for the alarm)

Communication options

  • Modbus TCP
  • Profibus
  • Profinet
  • other on request

As part of our SIRA measuring device series, we at UNION Instruments are pleased to introduce the first new, innovative UV process gas analyzer for odorization monitoring to the market.

- Peter Kienke

Larissa Lehmann

Larissa Lehmann
Product Management SIRA

Interested in more information about SIRA for measuring odorants concentrations?

Then feel free to call us or complete our contact form.