909

picto fleche Secondary Standard Platinum Resistance Thermometers, -200°C to 670°C

The 909 economically-priced secondary standard PRT -Platinum Resistance Thermometers- are the workhorse of calibration laboratories all over the world. The wide temperature ranges from -200°C to 670°C and economic pricing make these thermometers ideal for the secondary laboratory.

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The 909 economically-priced Standard Platinum Resistance Thermometers are the workhorse of calibration laboratories all over the world. The wide temperature ranges from -200°C to 670°C and economic pricing make these thermometers ideal for the secondary laboratory. For smaller uncertainties to suit the Primary Laboratory refer to the 670 SPRTs.

The resistance element is of pure platinum, coiled and mounted in a strain free construction. The former is of pure alumina material and all parts have been pre-aged to eliminate contamination and strain. All joints are welded to minimize resistance changes. The leads are brought to a handle assembly where they are connected to a low loss cable, 2 m long and screened.

The 909Q model has a Quartz sheath while the 909L and 909H have metal sheaths. Quartz glass thermometers have the advantage that the internal components are visible and can be inspected and continue to be our recommended models. The low temperature models have excellent immersion characteristics and a significant cost saving when compared to the higher temperature models.

Three thermometer lengths are available, standard length 480 mm, extra length 550 mm or maximum length 600 mm.

The Model 909 is supplied in standard with a traceability certificate at Water Triple Point and Fixed Point of Gallium. Alternatively we can provide a complete UKAS calibration certificate.

Key features:

  • Three stem lengths
  • Wide operating range

General specifications

Rtpw25.5 Ω100 Ω
Nominal resistance25.5 Ω at 0°C100 Ω
Recommended max current1 mA0.5 mA
Nominal sensitivity0.1 Ω /°C0.4 Ω/°C
Resistance ratioWga > 1.11807 as required by ITS-90
Self-heating1 mK / 26 µW
StabilityDepends on the temperature range of use. See table below for typical annual stability.
Internal leadsFour wire
External leadsSilver-plated multi-strand wires in a low-loss insulation cable terminating in gold-plated terminals.

Models 25.5 Ω

ReferenceTemperature rangeSheathDiameterLengthSensing lengthConstructionStandardNotes
909Q/25/480-200 to 670°CQuartz7.5 mm480 mm65 mmSealed with dry oxygen / argon mixITS-90Recommended secondary standard SPRT
909Q/25/550-200 to 670°CQuartz7.5 mm550 mm65 mmSealed with dry oxygen / argon mixITS-90
909Q/25/600-200 o 670°CQuartz7.5 mm600 mm65 mmSealed with dry oxygen / argon mixITS-90
909H/25/480-80 to 670°CMetal6 mm480 mm65 mmSealedITS-90Internal alumina tube protects sensor from contamination
909H/25/550-80 to 670°CMetal6 mm550 mm65 mmSealedITS-90
909H/25/600-80 to 670°CMetal6 mm600 mm65 mmSealedITS-90
909L/25/480-200 to 165°CMetal6 mm480 mm65 mmSealed with dry oxygen / argon mixITS-90Optimized for low temperatures, less stem conduction due to internal construction
909L/25/550-200 to 165°CMetal6 mm550 mm65 mmSealed with dry oxygen / argon mixITS-90
909L/25/600-200 to 165°CMetal6 mm600 mm65 mmSealed with dry oxygen / argon mixITS-90

Models 100 Ω:

ReferenceTemperature rangeSheathDiameterLengthSensing lengthConstructionStandardNotes
909Q/100/480-200 to 550°CQuartz7.5 mm480 mm65 mmSealed with dry oxygen / argon mixITS-90Recommended secondary standard SPRT
909Q/100/550-200 to 550°CQuartz7.5 mm550 mm65 mmSealed with dry oxygen / argon mixITS-90
909Q/100/600-200 to 550°CQuartz7.5 mm600 mm65 mmSealed with dry oxygen / argon mixITS-90
909H/100/480-80 to 550°CMetal6 mm480 mm65 mmSealedITS-90Internal alumina tube protects sensor from contamination
909H/100/550-80 to 550°CMetal6 mm550 mm65 mmSealedITS-90
909H/100/600-80 to 550°CMetal6 mm600 mm65 mmSealedITS-90
909L/100/480-200 to 165°CMetal6 mm480 mm65 mmSealed with dry oxygen / argon mixITS-90Optimized for low temperatures, less stem conduction due to internal construction
909L/100/550-200 to 165°CMetal6 mm550 mm65 mmSealed with dry oxygen / argon mixITS-90
909L/100/600-200 to 165°CMetal6 mm600 mm65 mmSealed with dry oxygen / argon mixITS-90

Typical uncertainties of 909 SPRTs with UKAS calibration

Fixed point°CRange 1Range 2Range 3Range 4Range 5Range 6
BP Nitrogen-195.79810 mK10 mK10 mK10 mK10 mK
TP Mercury-38.83442 mK2 mK2 mK2 mK2 mK2 mK
TP Water0.011 mK1 mK1 mK1 mK1 mK1 mK
MP Gallium29.76461 mK
FP Indium156.59853 mK3 mK
FP Tin231.9283 mK3 mK3 mK
FP Zinc419.5273.5 mK3.5 mK
FP Aluminium660.32310 mK

909                       Secondary Standard Platinum Resistance Thermometers, -200°C to 670°C

Delivered in standard with:

  • Traceable certificate at Water Triple Point and Fixed Point of Gallium
  • Carrying case

Models 25.5 Ω

ReferenceTemperature rangeSheathDiameterLengthSensing lengthConstructionStandardNotes
909Q/25/480-200 to 670°CQuartz7.5 mm480 mm65 mmSealed with dry oxygen / argon mixITS-90Recommended secondary standard SPRT
909Q/25/550-200 to 670°CQuartz7.5 mm550 mm65 mmSealed with dry oxygen / argon mixITS-90
909Q/25/600-200 o 670°CQuartz7.5 mm600 mm65 mmSealed with dry oxygen / argon mixITS-90
909H/25/480-80 to 670°CMetal6 mm480 mm65 mmSealedITS-90Internal alumina tube protects sensor from contamination
909H/25/550-80 to 670°CMetal6 mm550 mm65 mmSealedITS-90
909H/25/600-80 to 670°CMetal6 mm600 mm65 mmSealedITS-90
909L/25/480-200 to 165°CMetal6 mm480 mm65 mmSealed with dry oxygen / argon mixITS-90Optimized for low temperatures, less stem conduction due to internal construction
909L/25/550-200 to 165°CMetal6 mm550 mm65 mmSealed with dry oxygen / argon mixITS-90
909L/25/600-200 to 165°CMetal6 mm600 mm65 mmSealed with dry oxygen / argon mixITS-90

Models 100 Ω

ReferenceTemperature rangeSheathDiameterLengthSensing lengthConstructionStandardNotes
909Q/100/480-200 to 550°CQuartz7.5 mm480 mm65 mmSealed with dry oxygen / argon mixITS-90Recommended secondary standard SPRT
909Q/100/550-200 to 550°CQuartz7.5 mm550 mm65 mmSealed with dry oxygen / argon mixITS-90
909Q/100/600-200 to 550°CQuartz7.5 mm600 mm65 mmSealed with dry oxygen / argon mixITS-90
909H/100/480-80 to 550°CMetal6 mm480 mm65 mmSealedITS-90Internal alumina tube protects sensor from contamination
909H/100/550-80 to 550°CMetal6 mm550 mm65 mmSealedITS-90
909H/100/600-80 to 550°CMetal6 mm600 mm65 mmSealedITS-90
909L/100/480-200 to 165°CMetal6 mm480 mm65 mmSealed with dry oxygen / argon mixITS-90Optimized for low temperatures, less stem conduction due to internal construction
909L/100/550-200 to 165°CMetal6 mm550 mm65 mmSealed with dry oxygen / argon mixITS-90
909L/100/600-200 to 165°CMetal6 mm600 mm65 mmSealed with dry oxygen / argon mixITS-90