Fiber-film probes have cylindrical thin film sensors and may be used as a substitute for wire probes in liquids or in gas applications where more robust probes are needed. They are considerably more rugged than wire probes and less sensitive to contamination. Fiber sensors are 70 µm diameter quartz fibers, 3 mm long, covered by a nickel thin film approx. 0.1 µm in thickness.
The probe body is a 1.9 mm diameter ceramic tube, equipped with gold-plated connector pins that connect to the probe supports by means of plug-and-socket arrangements. Fiber probes are, furthermore, marked with symbols indicating applications in gas or liquids (red dot = air, blue dot = water).
Both coating types are available in five configurations. The picture on the right shows the dimensions common for the Single-sensor fiber-film probes.
Mounting: 4mm. Probe Supports.
Fiber-film probe, straight (55R01 and 55R11)
Probe with straight prongs and with the sensor perpendicular to probe axis. Probe 55R01 has a thin coating (0.5 µm) and probe 55R11 has a heavy coating (2 µm).
Fiber-film probe, thin or heavy coating, 45 deg. (55R02 and 55R12)
Probe with straight prongs and with the sensor at an angle of 45° to probe axis. Probe 55R02 has a thin coating (0.5 µm) and probe 55R12 has a heavy coating (2 µm).
These probes can be used when measuring mean flow velocities, flow fluctuations and Reynolds shear stress in stationary two- and three-dimensional flows. Mounts with the probe axis parallel to the direction of the mean flow. The probe is rotated to get the velocity components.
Fiber-film probe, right angle, parallel (55R03 and 55R13)
Probe with right-angled prongs and with the sensor parallel to probe axis. Probe 55R03 has a thin coating (0.5 µm) and probe 55R13 has a heavy coating (2 µm)
Fiber-film probe, right angle, perpendicular (55R04 and 55R14)
Probe with right-angled prongs and with the sensor perpendicular to probe axis. Probe 55R04 has a thin coating (0.5 µm) and probe 55R14 has a heavy coating (2 µm).
Used in the same applications as 55R03 and 55R13, except that the sensor is turned 90°. This makes these probes suitable for boundary layer measurements, e.g. in pipes, as well. Mounts with the probe axis perpendicular to the direction of the flow.
Fiber-film probe, boundary layer (55R05 and 55R15)
Probe with offset prongs and with the sensor perpendicular to probe axis.
This probes are designed for use in boundary layers. The shape of the prongs permits measurements close to a solid wall without disturbance from the probe body, which is out of the boundary layer. Mounts with the probe axis parallel to the direction of flow.
|Technical Data For Fiber-film Sensors|
|Thickness of quartz coating||0.5 µm||2 µm|
|Sensor dimensions||70 µm dia, 1.25 mm long
The overall fiber lenght is 3 mm
|Sensor resistance R20 (approx.)||6 Ω|
|Temperature coefficient of resistance (TCR) α 20 (approx.)||0.40%/°C|
|Max. sensor temperature||300°C||60°C 1),2)|
|Max. ambient temperature||150°C||100°C|
|Min. velocity||0.05 m/s 3)||0.01 m/s|
|Max. velocity||350 m/s||10 m/s|
|Frequency limit fmax||175 kHz||30 kHz|
- At atmospheric pressure (1 bar)
- Max. 150°C at elevated pressure. Avoid bubble formation.
- Influence from natural convection up to approx. 0.20 m/s.