#4 Thermowells

To Measure Fluid Temperature

  • Resistance or Thermocouple Temperature Measurement
  • ABB, Honeywell, Yokogawa and more brands available
  • Available with temperature sensing element and thermowell


Temperature measurement as it pertains to differential pressure flow meters allows for accurate determination of fluid properties. This measurement is particularly important when measuring fluids such as gases and steam where viscosity and density change significantly as a function of temperature. Temperature measurement typically consists of a sensing element that is housed within a thermowell inserted into the process fluid. The sensing element produces a signal that is interpreted by a temperature transmitter or sent to a multivariable dP flow transmitter.


Temperature Transmitters convert the input signal from a Temperature Sensing Element such as an RTD or Thermocouple into an analog or digital signal output which can be read locally at the transmitter or sent to a PLC or SCADA system.
Sensing Elements
Temperature Sensing Elements can either be resistance or voltage based. Resistance-based sensing elements are known as resistance temperature detectors (RTD’s) and voltage-based designs are called Thermocouples. In general, RTD sensors are best used where high accuracy and repeatability is required. Thermocouples may be used for very high temperature service (1000F+).
Thermowells are used to isolate the sensitive temperature sensing element from the process fluid. Sensing elements are inserted into the thermowell. The thermowell is inserted directly into the process fluid and protects the element from potential damage from the line fluid.
Most gases, steam, liquids.
Common Materials
Transmitter: Stainless Steel / Aluminum Housings Sensing Elements: RTD’s (Platinum thin-film/wire-wound), Thermocouples (Type J/K/T) Thermowells: 304SS / 316SS

Support and Service

In addition to a wide range of differential producing Venturi flow meters, orifice plates, WedgeType™ flow meters, and open channel flow elements, PFS provides comprehensive, specialized services for new and existing flow meters, including rehabilitation, hydraulic analysis, and full engineering support.


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