Fluke 5608-9-X Secondary PRTs

Fluke Calibration

Fluke Calibration authorised distributor.

The Fluke 5608 thermometer is classified as secondary standard. A secondary standard is used to transfer the ITS-90 from a standards laboratory to a customer’s laboratory.

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£ 461.00

(£ 553.20 inc VAT.)

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The Fluke Calibration Platinum Resistance Thermometers (PRT) models 5608 and 5609, are designed to be a secondary standard interpolating instrument converting temperature to resistance. The PRTs are used with a readout device to detect temperature changes or actual temperature.

The 5608 is also a ± 7 mK probe at the triple point of water, but its one-eighth inch (3.18 mm) diameter gets you accurate measurements from –200 °C to 500 °C with only 80mm (3.1 in) of immersion. When looking for improved response time and reduced stem effect in shallow immersion, look for small diameter probes, because the measurement error called stem effect is caused by the diameter of the stem rather than the length of the stem.

The Fluke 5608-9-X probe has an Inconel™ sheath and is made using a special manufacturing process, giving it great precision over a wide temperature range. The sensors for these probes are reference-grade platinum and feature four-wire connections with less noisy measurements than two-wire counterparts.

In order for any instrument to be used as a standard it must be calibrated. These instruments are sold uncalibrated unless calibration is requested at time of purchase. They are satisfactory as secondary standards and may be calibrated by comparison to primary standards.

Please Note: When ordering please specify the termination you require. ie. Fluke 5608-9-G (gold pins).

X = termination.

Specify “A" (INFO-CON for 914X), “B" (bare wire), “D" (5-pin DIN for Tweener Thermometers), “G" (gold pins), “I" (INFO-CON for 1521 or 1522), “J" (banana plugs), “L" (mini spade lugs), “M" (mini banana plugs), “P" (INFO-CON for 1523 or 1524), or “S" (spade lugs).


Secondary Reference PRT, 9 in x 1/8 in, –200 to 500 °C, lead wire (cable) 6 ft.
Calibration not included.

Fluke 5608-9-X Specifications:

  • Temperature range: –200 °C to 500 °C.
  • Nominal resistance at 0.01: °C 100 Ω ± 0.5 Ω.
  • Temperature coefficient: 0.0039250 Ω/Ω/°C.
  • Short-term repeatability: ± 0.01 °C at 0.010 °C, ± 0.02 °C at max temp.
  • Sensor length: 30 mm ± 5 mm (1.2 in ± 0.2 in).
  • Sensor location: 3 mm ± 1 mm from tip (0.1 in ± 0.1 in).
  • Sheath dimensions, length x diameter 5608-9: 229 x 3.18 mm (9 in x 0.125 in).
  • Sheath diameter tolerance: ± 0.1 mm (± 0.004 in).
  • Sheath material: Inconel™ 600.
  • Transition junction temperature range: –50 ºC to 200 °C.
  • Minimum immersion length: 80 mm (3.1 in).
  • Maximum immersion length: 305 mm (12 in).
  • Lead-wire length: 1.8 m (6 ft).
  • Calibration: Not included.
  • Fluke 5608-9 Warranty: 1 year.

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Fluke 5608-9-X Secondary PRTs