TNF Capillary Thermometer

Brand: KOBOLD Instruments, Inc.

The measuring system of the gas pressure thermometer comprises probe, capillary tube and Bourdon tube in a casing. These parts form a unit. The complete measuring system is filled with pressurized nitrogen.

A change in temperature causes a change in inner pressure in the immersion shaft.

The resulting deflection of the Bourdon tube is transferred to the pointer through a pointer element. Display and probe are connected by a capillary tube separated by a distance up to 100 m.

A version filled with glycerine is available as an option for service at measuring points exposed to strong vibrations.

The fill dampens the measuring system when exposed to mechanical vibrations and thus enables steady indication; it also provides good lubrication for moving parts.

We recommend our robust Aluminum casing for rough field service conditions. These thermometers can also be used with aggressive measuring substances when fitted with a suitable thermowell.



  • Class 1
  • Class 1.6


  • Chemical Industry, Petrochemicals
  • Food Industry
  • Mechanical Engineering & Heavy Goods Industry
  • Piping & Vessel Construction
  • Process Engineering

Enclosure / Body Material

  • 304L Stainless Steel with Bayonet Lock
  • Aluminum (100 or 160 mm) with Steel Ring Cover
  • Brass Chromium
  • Noryl Black - Profile Housing
  • Stainless Steel
  • Steel Black - Profile Housing

Environmental Protection

  • IP65

Materials of Construction

  • 316Ti Stainless Steel with Flexible Reinforced Protective Hose - Capillary Tube
  • Aluminum - Pointer & Dial
  • Brass - Pointer Element
  • Steel with PVC Jacket - Capillary Tube

Screw Material

  • 304 Stainless Steel

Sensor / Probe Diameter

  • 0.31" (8 mm)
  • 0.35" (9 mm)
  • 0.39" (10 mm)
  • 0.47" (12 mm) Standard

Sensor / Probe Material

  • 304 Stainless Steel

Temperature Range

  • -40° to 600° C (-40° to 1,112° F)

Window Material

  • Instrument Glass 4 mm with Aluminum Case
  • Plexiglass
  • Safety Glass


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