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Jerome® 651

Gold Film Fence-line Hydrogen Sulfide Monitoring System

The Jerome® 651 monitoring system from Arizona Instrument LLC is the system you need to solve your hydrogen sulfide monitoring problems. Designed to provide long-term monitoring even in extreme weather conditions, it can be stationed at any location. Multiple units can be linked to form a perimeter monitoring system. Data logging and radio telemetry capabilities make downloading data convenient and easy from a remote PC.


  • Unattended:
    The 651 is designed for set-and-forget hydrogen sulfide monitoring, inside or out.


  • Flexible:
    A detachable hand-held hydrogen sulfide analyzer is contained within the unit for pinpointing a gas source.

  • Smart Alarms:
    Define alarm points that meet your needs and receive email notifications and warnings.

  • Wireless:
    Measurement data is transmitted wirelessly from 651 stations to the user’s PC.

  • Rugged:
    The 651 is housed in a Nema-rated box, insulated, air conditioned and ready for nearly any environment.

Contact our sales team for more information on our Jerome series.

  • Specifications +

    Instrument Specifications

    Detection Range: 3 ppb (0.003 ppm) to 50 ppm
    Resolution: 0.001, 0.01, 0.1, and 1 ppm
    Accuracy: ±0.005 ppm at 0.05 ppm
    ±0.05 ppm at 0.5 ppm
    ±0.5 ppm at 5 ppm
    ±2 ppm at 25 ppm
    Sample Intervals: 1, 2, 5, 10, 15, 30, 60 or 120 minutes
    Regeneration Intervals: 6, 12, 24 and 48 hours
    Flow Rate: 150 mL/min
    Operating Environment: -40 to +55°C, non-explosive, 0-100% relative humidity
    Result Units: ppm, ppb
    Data Storage Capacity: 50,000 readings
    Power Requirements (651 Unit): 100-120 VAC, 50/60 Hz, 7 A or
    210-240 VAC, 50/60 Hz, 4 A
    Control Board Fuse: Fast-acting IEC 1.6 A 250 V, 5 mm x 20 mm
    Case Construction: Polyester with insulation to reduce heat transfer
    (Detatched 631-X Unit):
    Rechargeable NiCad
    6 hour life
    Estimated Sensor Life: 3 to 6 months depending on operating conditions
    Display: 8 digit alphanumeric LCD
    Output: Nano Radio
    Analog: 4-20 mA passive current loop
    Dimensions: 26″ W x 25″ H x 9″ D
    (67 cm W x 64 cm H x 23 cm D)
    Weight: 52 lbs. (24 kg)
    Warranty: 1 year, factory parts and labor except for 631-X sensor


    Nano Radio Modem Specifications

    Frequency: 2.4 – 2.4835 GHz (2400 MHz)
    49 selectable channels
    Serial Interface: RS-232
    Power Requirements: 10-30 VDC, 450 mA
    Operating Temperature: -40°C to 75°C
    Range: Up to 4 miles (6.4 km) “line of sight.”
    Longer distances may be obtainable
    through use of a high gain antenna
    or by using the optional Radio Repeater

  • Features +

    Perimeter Monitoring: Multiple Jerome® 651 units can be linked to form a perimeter monitoring system to help locate the source of H2S and ensure safety and compliance.

    Detachable Unit: Quickly and easily sweep an area for hydrogen sulfide hot spots with the detachable, hand-held Jerome® 631-X hydrogen sulfide analyzer.

    Gold Film Sensor: Validated in the field and in the lab for over 35 years, our proprietary gold film sensor ensures repeatable results across a wide range of applications.

    Weather Station: An attached weather station monitors outside temperature as well as wind speed and direction for increased accuracy in pinpointing the source of odor contamination.

    Data Transmission: Advanced data logging and radio telemetry capabilities make downloading data to a remote PC easy and convenient.

    PC Software: Intuitive PC software with user selectable time-weighted average reporting and a site view tab give users a bird’s eye view of the monitoring system as a whole.

    Programmable Alarms: The 651 comes with programmable alarms that automatically send email alerts if your H2S levels rise above your specified upper limit.

    Temperature Controlled Interior: Resistive heating and thermoelectric cooling keep the interior of the 651 at a consistent temperature for increased accuracy.

    Regulatory Compliance: The 651 is in active use by many regulatory agencies and landfill, water treatment and wastewater management facilities across the world.

  • Documents & Downloads +

  • Accessories Parts Consumables +

    Part Number Description
    200-0173 Antenna, 2400 MHz, 8 DB (High Gain)
    200-0181 Lightning Arrestor, 2400 MHZ
    800-0065 Vacushield Filter
    980-0010 Wind Gauge (Anemometer)
    990-0194 Thermo-Electric Cooler
    2300 0001 Trimmer Tool
    PS-151 Tube Nut
    Y990-0194 Accessory Kit
    Y990-0195 Flow Pump Kit
    Y990-0279 Nano Radio Modem Kit
    Y990-0200 Chlorine Filter Kit
    Y990-0202 Ammonia Filter Kit
    Y990-0278 Radio Repeater Kit
    Y2600 3945 Straight Intake Kit
    Z2600 0918 Jerome® Functional Test Module, 250 ppb, 115V
    Z2600 0930 Jerome® Functional Test Module, 30 ppb, 115V
    Z2600 3905 Zero Air Filter
    Z2600 3930 Scrubber Filter
    Z2600 3933 Scrubber Filter, LFS
    Z2600 3934 Scrubber Filter, LFD