Open Path Monitoring

Real-time,multi-gas, open path systems.

The Opsis System measures multiple gases over an
Open Path using the DOAS (Differential Optical Absorption Spectrosocopy) technique.

  • Can be configured to measure multiple gases in one system including NO, NO2, SO2, O3, Benzene, Toluene, Xylene, Formaldehyde, NH3 etc.
  • Fast Response, Optical Monitoring technology
  • Non-contact, no pumps, valves, sample lines etc.
  • Representative 'path-averaged' ambient air monitoring


Watch our Opsis Open-path video

Applications Include:

  • Urban
  • Background and Industrial Fenceline

    You will find more information on the specific applications for the Opsis Open Path system in the data section of this page by clicking on the tab above.

    OPSIS System 300 – Diffential Optical Absorption Spectroscopy (DOAS)

    The basic OPSIS system 300 measures SO2, NO2 and O3. The system comprises of the AR 500 UV DOAS analyser (differential optical absorption spectroscopy), ER 110 emitter/ receiver, PS 150 power supply unit and 10m fibre optic cable.

    OPSIS System 300 Extended – Diffential Optical Absorption Spectroscopy (DOAS)

    Additional gases (ie. benzene, toluene, xylene) can be added at extra cost.

    The AR500 Open Path Monitor has MCERTS Approval

All Opsis instruments are sold with 1 years parts warranty as STANDARD.

The warranty can, at additional cost, be extended for total peace of mind. Please call to discuss options for this.

Opsis instruments require periodic service and maintenance to both satisfy the requirements of the warranty and to ensure that the highest possible data capture rates are maintained.

Enviro Technology has a large team of in-house and field based service engineers who regularly receive “factory training” and can provide the very best levels of service and support.

Enviro Technology and Opsis recommend that the Open Path System is serviced every 6 months of continuous operation.

A wide range of servicing options are available and can include:

- Pre-scheduled on-site planned maintenance (every 6 months).

- Emergency on-site call-out within agreed timescales (i.e. 48 hours).

- Supply of consumable items (i.e. sample inlet filters).

- Supply of calibration gases and permeation tubes.

- Supply of permeation tube calibrators and zero air generators

- Remote analyser “health-checks” and diagnostics.

- Return-to-base servicing options.

- Local site operation services.

- Data collection and data management services.

Please contact either our sales or customer services teams to request a quotation for on going servicing and maintenance on this analyser.

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