AM1860/1850 SPRTs

Standard Platinum Resistance Thermometers (SPRTs) are common used to interpolate temperature in the range from -189.3442°C to 660.323°C on the International Temperature Scale of 1990 (ITS-90). They are widely used as standard or reference thermometers to calibrate other thermometers and to measure temperature precisely in primary and secondary laboratories. AM1850 and AM1860 SPRTs are the crown jewels of AccuMac temperature probes. It takes decades of our scientific expertise and original craftsmanship to create these world class products. They feature a very low drift rate.
To improve the durability of the SPRT, Inconel 600 replaces quartz glass as sheath material of the thermometer. A special capsule is adopted to protect the platinum sensor wire from contamination introduced by metal sheath at high temperature. All parts used in the thermometer are completely cleaned and treated at high temperature before assembly. The gas mixture filled in the thermometer is well controlled to reduce oxidation effect as low as possible. Every SPRT is fully tested for stability after manufactured. This world class probe meets ITS-90 criteria of standard thermometer fully with a very competitive pricing.
AM1850 has a temperature range from -200°C to 500°C. AM1860 covers range from -200°C to 670°C. They are widely used as reference thermometer at drywell block calibrator and temperature bath.


    Temperature Range
    1850: -200°C to 500°C
    1860: -200°C to 670°C
    Nominal 25 Ω or nominal 100 Ω
    Resistance Ratio
    Drift at 0.01°C*
    1850      ΔR(0.01°C ) <0.002 °C/100 hours at 500°C
                    ΔR(0.01°C ) <0.008 °C/year
    1860      ΔR(0.01°C ) <0.003 °C/100 hours at 670°C
                    ΔR(0.01°C ) <0.01 °C/year
    ±0.0015 °C
    Thermal Shock
    ±0.0015 °C after 10 times thermal cycles from minimum to maximum temperatures
    0.0015 °C at 1 mA current
    Measurement Current
    1 mA
    Sensor Length
    42 mm
    Insulation Resistance
    >1000 MΩ at room temperature
    Sheath Material
    1850: 6.35 mm (OD) X 480 mm (L)
    1860: 6.35 mm (OD) X 500 mm (L)
    External Leads
    Insulated copper wire, 4 leads, 2.5 meters
    Gold-plated Spade
    Handle Dimension
    21mm (OD) X 80 mm (L)
    Not included

  • Optional Accessories

    Complementary Wooden Carrying Case

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    TypeStandard BathCustom Bath

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