Fluke Calibration

5649 / 5650 Type R and Type S Thermocouple Standards

Eight reference thermocouple models to fit any type R or S high-temperature thermocouple application

Starting At
$5,100.00 CAD
Normally ships in 1-2 Weeks

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Made from the finest platinum and platinum-rhodium alloy, these type R and S thermocouples cover a temperature range of 0°C - 1450°C with uncertainties as good as +/- 0.15°C over most of that range. With four different models for each type, we have the type R thermocouple and type S thermocouple to fit your application.

The measuring junction of both the 5649 and the 5650 is encased in a 0.25 in (6.35 mm) alumina sheath that can be ordered in lengths of 20 in or 25 in (50.8 cm or 63.5 cm) to fit the specific requirements of your application. A reference, or “cold," junction may also be ordered. The reference junction uses a stainless steel sheath and is 8.25 in long (21 cm) by 0.188 in in diameter (4.8 mm). The thin diameter minimizes the immersion depth needed, but the extra length ensures you can get all the immersion you like.

Special tin-plated, solid-copper connecting wires with ultra-low EMF properties are used to help retain the integrity of your measurement junction where the probe attaches to your micro voltmeter or Hart Black Stack.

Each probe comes from a spool of wire that has been sample tested using fixed-point standards to ensure uncertainties less than 0.5°C up to 1100°C. From 1100°C - 1450°C, the uncertainty increases linearly to 3.0°C. If you need greater accuracy, order an individual calibration with fixed-point standards to reduce uncertainties to +/- 0.15°C up to 962°C, +/- 0.25°C up to 1100°C, and increasing linearly to +/- 2.0°C at 1450°C.

The probe assembly can be easily disassembled for performing your own bare-wire calibrations.


• Designed by the Fluke Calibration primary temperature standards design team
• Two sizes available, each with or without reference junction
• Uncalibrated accuracy is the greater of +/- 0.6°C or +/- 0.1% of reading

Range 0C - 1450C
Type Type R: Platinum/13% Rhodium vs. Platinum
Type S: Platinum/10% Rhodium vs. Platinum
Calibration Optional fixed point calibration uncertainties (k = 2): +/- 0.15C up to 962C, increasing linearly to +/- 2.0C at 1450C
Hot Junction Sheath Dimensions 6.35 mm (0.25 in) diameter; see Ordering Information for lengths
Reference Junction Sheath Dimensions 4.8 mm dia. x 210 mm long (0.188 in x 8.25 in)
Long-Term Stability +/- 0.5C - 1100C
+/- 2.0C - 1450C (over one year depending on usage)
Short-Term Stabilities +/- 0.2C - 1100C
+/- 0.6C - 1450C
Immersion At least 152 mm (6 in) recommended
Protective Case Model 2609 case included
Weight 1 kg (2 lb)
Plastic probe carrying case for probes 635 mm (25 in) in length
Normally ships in 1-2 Weeks
$301.00 CAD