Thermo Scientific™ Orion™ 261S Basic Waterproof Portable pH Meter Available on GSA/VA Contract for Federal Government customers only.

Measure pH, mV and temperature using the Thermo Scientific™ Orion™ 261S Intrinsically Safe (US) Portable pH Meter

Manufacturer: Thermo Scientific™ 0261S0

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Catalog No. 13-641-691


This item has been discontinued by the manufacturer and is no longer available. Please call customer service for assistance: 1-800-766-7000. 


    Warranty 3 year meter warranty
    Calibration pH
    Temperature Selection Automatic with ATC temperature probe
    Model Orion Intrinsically Safe 261S pH/mV/Temperature Portable Meter
    Channels 1
    Keypad Measure, cal, scroll up, scroll down, power keys
    Measurement Modes pH with mV and temperature
    Item Description Orion Intrinsically Safe 261S pH portable meter with sensor
    Languages English
    Outputs None
    Power Supply 3 AA batteries (included)
    Dimensions (L x W x H) 16cm x 13.3cm x 3cm (6.30 in. x 5.24 in. x 1.18 in.)
    Weight (English) 1.4 lb.
    Weight (Metric) 0.6kg
    Backlight Option None
    Description Orion Intrinsically Safe 261S pH portable meter with sensor
    Resolution (mV) 0.1mV
    Range (Temperature) -20° to 120 °C, -4° to 248° F
    Accuracy (Temperature) ±0.3°C
    Inputs E-DIN Waterproof (pH electrode), banana plug (ATC temperature probe)
    Includes Orion 261S pH meter, 9109WP Orion Triode gel-filled epoxy-body pH/ATC electrode with 1.5 meter cable, 3 AA batteries
    IP Rating IP-66
    Certifications/Compliance CE, FM (IS, Class I Div 1 Group A, B, C, D, T4), Ex (Intrinsically Safe)
    Resolution (pH) 0.1, 0.01pH
    Range (mV) ±1300.0mV
    Display Type LCD
    Probe Type pH electrode, ATC temperature probe (includes 9109WP Orion Triode pH/ATC electrode)
    Temperature (English) Operating 14° to 131°F (ambient)
    Temperature (Metric) Operating -10° to 55°C (ambient)
    Accuracy (pH) ±0.01pH
    Accuracy (mV) 0.1% of reading ±0.3 mV
    Calibration Points (pH) 1 to 3
    Resolution (Temperature) 0.1°C
    Battery Life 1000 hours
    Battery Type Three AA (included)
    Range (pH) -2.00 to 16.00pH

    Measure pH, mV and temperature in environments where non-sparking equipment is required using the Thermo Scientific™ Orion™ 261S Intrinsically Safe (US) Portable pH Meter. Intrinsically safe approval rating by Factory Mutual (FM) for US only.


    • 2.00 to 16.00pH range
    • -20° to +120° temperature range
    • ±1300mV range
    • Safely measure in hazardous and confined space environments and anywhere nonsparking equipment is desired
    • Battery-operated
    • Large, easy-to-read display to monitor electrode condition, calibration status and pH, mV and temperature readings
    • Automatic or manual calibration with up to three calibration points


    • Meter Only package includes meter, built-in quiver, neckstrap and instruction manual
    • Meter/Electrode package includes meter, Triode™ 3-in-1 Combination pH Electrode, built-in quiver, neckstrapand instruction manual
    • Meter Field Kit package includes meter, built-in quiver, neckstrapand instruction manual, case, stand, electrode holder, beakers, 4, 7, 10 buffers, RS232 cable and software

  • Description & Specifications

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