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Thermo Scientific™ Orion™ 261S Basic Waterproof Portable pH Meter

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

Manufacturer:  Thermo Scientific™ 0261S2

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Catalog No. 13-650-112

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



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


Orion Intrinsically Safe 261S pH portable meter
Orion Intrinsically Safe 261S pH portable meter
-2.00 to 16.00pH
-20° to 120 °C, -4° to 248° F
Measure, cal, scroll up, scroll down, power keys
3 AA batteries (included)
Three AA (included)
CE, FM (IS, Class I Div 1 Group A, B, C, D, T4), Ex (Intrinsically Safe)
-10° to 55°C (ambient)
1.4 lb.
Orion Intrinsically Safe 261S pH/mV/Temperature Portable Meter
Orion 261S pH meter, 3 AA batteries
0.1, 0.01pH
0.1% of reading ±0.3 mV
1 to 3
Automatic with ATC temperature probe
pH with mV and temperature
E-DIN Waterproof (pH electrode), banana plug (ATC temperature probe)
pH electrode, ATC temperature probe (purchase separately)
1000 hours
14° to 131°F (ambient)
16cm x 13.3cm x 3cm (6.30 in. x 5.24 in. x 1.18 in.)
3 year meter warranty
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