Gas Sensors

Innova 3731

SF6 Leak Detection System for Enclosed GIS Substations

The Advanced Energy Innova 3731 SF6 leak detection system uses photoacoustic spectroscopy (PAS) technology. It offers highly accurate and stable quantitative gas detection.

  • Available in 12- or 24-channel configuration to monitor large GIS installation
  • Simple installation procedure
  • Low cost of ownership
  • Multipoint sampling
  • Detection trending and automatic alarms
  • Overview
  • Technical Specs
  • Documents
  • Accessories
  • Service & Support
  • Distributors


Advanced Energy’s Innova® 3731 SF6 system utilizes the ultra-sensitive photoacoustic sensing technique to provide a leak detection solution that monitors large switchgear rooms. The system verifies that GIS equipment operates below the 0.5% yearly leakage rate, which is the industrial target. And the 3731 system quickly detects any excessive increase in the leak rate.

Analog output is available for detection trending over time. Measurements are also stored in the internal memory. They can be exported to a remote LAN computer via the user-friendly software interface.


  • Calibrate the monitor once a year (no equipment outage needed)
  • Lower costs
  • Set up tasks using either the remote/offline software or the front panel push-keys
  • Enable a direct and integral leak detection solution that can monitor large switchgear rooms
  • Achieve exceptional accuracy


  • Standalone Multipoint SF6 leak monitor with superior photoacoustic detection (detection limit = 6 ppb)
  • Independent from pressure or density readings
  • Highly reliable and stable
  • Extensive sampling-point distribution over the whole enclosed substation
  • Monitor and sampler units are rack-mountable on a standard 19 in chassis
  • Measurement Specifications

    Detection Limit

    0.006 ppm at 5 SIT

    Dynamic Range

    Typically four orders of magnitude (i.e. 10,000 times the detection limit at 5 SIT); using two-span concentrations it can be expanded to five orders of magnitude


    1% of measured value
    (Measured at 20°C, 1013 mbar, and relative humidity (RH): 60% (a concentration of 100x detection limit4 was used in determining these specifications)


    The 3731 automatically compensates for temperature and pressure fluctuations in its analysis cell and can compensate for water vapor in the air sample; if an optical filter is installed to measure a known interferent, the 3731 can cross compensate for the interferent

    Internal Data Storage Capacity

    The total space available in display memory to store data ia 131072 measurement cycles; one cycle is measurement of SF6 and water vapor on a given channel

  • Environmental Specifications

    Operating Temperature

    5 to 40°C (41 to 104°F)


    Max relative humidity 80% for temperatures up to 31°C decreasing linearly to 50% relative humidity at 40°C


    IP 20

    H x W x D

    175 x 483 x 375mm (6.9 x 19 x 14.8 in)


    24.5 kg (53.5 lb)

  • Pumping System Specifications

    Pumping Rate

    30 cm3/s (flushing sampling tube)
    5 cm
    3/s (flushing measurement chamber)

    Air Volume Per Sample

    Total Internal Volume

    60 cm3 (of the measurement system)

  • Electrical and Communication Specifications

    Power Ratings

    ~135 VA (monitor and sampler); 100 to 240 VAC ±10%, 50 to 60 Hz

    Alarm Relay Socket

    For connection to one or two alarm relays (visual/audio)
    Alarm levels for each gas are user-defined
    System On/Running status available
    Max 25 VDC, max 100 mA

    Back-Up Battery

    3 V lithium battery, lifetime 5 years

    Monitor Interface

    Three interfaces: USB, Ethernet, and RS232, for data exchange and remote control of the instrument

    Software Communication

    Via USB or Ethernet interface

  • Safety and Standards Specifications


    EN/IEC 61010-1 3rd Edition: Safety Requirements for electrical equipment for measurement, control, and laboratory use.


    EN 61326-1:2013: Electrical equipment for measurement, control and laboratory use – EMC requirements; Part 1: General requirements

    Standards Compliance

    CE-mark indicates compliance with: EMC Directive and Low Voltage Directive

  • Typical Applications

    • SF6 leak detection in enclosed GIS substations

Specifications are subject to change without notice. Not all options and accessories are available for all models and configurations. Dimensions listed generally refer to standard configurations and module bodies only. Please confirm technical specifications and customizations with a sales representative. Advanced Energy is not responsible for errors or omissions.


bz7003 Offline Software

Innova BZ7007 Remote & Offline Software

BZ7007 Software is used during set-up and to retrieve data from a stand alone system where the gas monitor is used as the system controller

Documents & Support

View All Innova 3731 Accessories

Global Support & Services

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Product Support

U.S.: +1 800 446 9167
Asia: +86 29 8874 1895
China: 400 8899 130
EMEA: +44 800 032 1546
U.K.: 08000 321 546

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