RHF series

RHF-series Ring heat flux sensors

RHF specifications:
Nominal Sensitivity 4 μV/kWm-2
Temperature range (sensor including metal sheathed cable) to +800 °C
Temperature sensing (T) thermocouple type K
Calibration traceability NIST
Response time (typical) 120 s (90%)
Cooling air or oil (user responsibility)
Dimensions according to customer specifications
Figure 1 Example of RHF01 ring heat flux senor consists of four temperature / heat flux sensors (1), in a stainless steel housing (2), with either flat connection for welding- (3) or alternatively threaded connections (4). Metal sheathed wire (5) is usually extended with Teflon wire (7). The sensor is typically incorporated in so-called deposition probes. Cooling should be provided by either air or oil. Dimensions in the drawing are only serving as example. All dimensions are in mm.

The RHF series consists of heat flux sensors designed for studies of fouling behaviour during combustion processes. A RHF is meant to be part of so-called "deposition probes" or "fouling sensors" (typically designed by the user) in slagging and fouling experiments. A typical sensor actually contains 4 separate heat flux / temperature sensors, so that directional fouling information can be obtained as well.

A nice clear print of the original product brochure.


RHF-series has been designed to be used in scientific as well as operational experiments to study fouling behaviour.
The user can build his own deposition probe or fouling sensor, and use a RHF (or an adapted version of it) as a building block. In practice many RHF sensors are built into probes that also measure temperature and take gas samples (so-caled suction probes).
RHF’s can be supplied in many different dimensions.

Compared to traditional deposition probe designs, advantages of a RHF are that it can provide "directional" information, and that calibration is no longer an issue. The latter is done at the manufacturer. In addition the calibration is far better under control (even traceable) and response times are faster.

RHF01 is provided with 4 calibration constants; one for every sensor.

Suggested Use

  • Studies of combustion processes
  • Studies of fuel fouling behaviour

More Information

  • Hukseflux is specialised in manufacturing of slagging and fouling sensors; the design can be adapted according to customer’s requirements
  • Hukseflux can also build the entire deposition probe
Version 0617