Applications Notes
See how Philtec fiber optic sensors solve measurement challenges in aerospace, energy, cryogenics, medical technology, vacuum systems, high-pressure environments, and advanced research applications.
Aerospace
84_Rocket Launch and Smallsat Apps
Overview of Philtec fiber optic displacement sensors for global space launch and small satellite applications: cryogenic rocket engine turbopumps, satellite propulsion in vacuum, aircraft engine testing, and custom multi-part sensor systems for extreme aerospace environments.
66_CTP Cryogenic Turbopump Speed Measurements
Application of reflectance dependent D-type sensors for turbopump RPM measurement by detecting propeller blade passage at 1/rev. Includes TTL output option for binary speed detection during full-scale rocket engine testing.
High Pressure
64-Extreme High Pressure Applications
Compares three probe sealing methods for high-pressure applications: epoxy-filled tips, sapphire windows epoxied in counterbores, and brazed sapphire windows. Includes pressure window thickness formula and design factors for static, pulsing, and combined extreme conditions.
Fiber Optic Fundamentals
24_Reflectance Dependent
D-type sensors provide an output proportional to the distance and reflectance of the target. The output function is double-valued: Near-Side operation provides the highest resolution, while Far-Side operation offers moderate sensitivity with a larger operating range.
85_FO Sensor Systems
Philtec offers four versatile sensor system configurations to suit diverse operational requirements. These include the One-Part System, where the fiberoptic cable is permanently attached to the amplifier; the Two-Part System, which incorporates a cable- or bulkhead-mounted connector; and the Three-Part Vacuum Passthru or Extension Cable systems, which utilize either a dedicated vacuum flange or dual in-line connectors for specialized installation needs.
V6N9_ValveDynamics
Measurements of valve and actuator dynamics require very small sensors with wide bandwidth. Philtec fi beroptics are perfectly suited for these applications.
25_Reflectance Compensation
The PHILTEC Reflectance Compensated (RC) fiberoptic sensor uses a ratiometric calculation of two detector signals to measure distance independently of target reflectivity. This makes the sensor output blind to surface reflectance variations.
71_Temperature Limits
Planning an installation in a high-temperature or extreme environment? Download Application Note 71 to verify the operational temperature ranges for our fiberoptic sensors. Use this reference to match the correct sensor tip, cable jacket, and electronics to your project's specific thermal profile.
26_RC Sensors Illustrated
Visual guide to reflectance compensated sensor operation with examples including bearing/rotor dynamics, in-process dimensional control, part-to-part measurements, and Z-axis distance with X/Y travel. Explains when RC sensors are required over D-type sensors.
30_Measurements in Fluids
Explains how submersion in fluids collimates light rays and extends sensor operating range by approximately 30%. Includes refractive index table, calibration requirements per medium, and Philtec experience with cryogenic rocket engine fluids (LH2, LOX, methane).
Cryogenics
50-MRI
Philtec’s ϐiber optic sensors are playing a vital role in a prototype which is very important for assessing the design. Displacements of many items inside the cryogenic system are being measured successfully to sub-micron level resolution.
63 Extreme Cryo Pressure
A new generation of LOX/Methane engines are under development, and many have used Philtec’s FODS (Fiber Optic Displacement Sensors) for rotor dynamics measurements in the testing phase. Fiber optic probes are an ideal sensor choice in these applications where they are exposed to pressurized cryogenic fluids.
Glass
48_HDD
A customer inquired whether or not we could detect the axial runout (wobble) of a hard disc drive to establish a pass/fail criteria at ±20 μm pk-pk.
65 Glass Thickness
With light based sensors, light rays will reflect off the front and the back surfaces of clear glass. The thickness of clear glass can be measured by using two sensors, with one mounted on each side of the glass.
V6N30_NeedleBrg
Philtec’s model RC100 fi beroptic probe with a 100 mil diameter fi ber optic probe proved to be the perfect fi t for this application. The probe is small, operation simple and the data very reliable. A mini-DMS unit with a TTL output comprises the automated inspection package
V6N31_Transparent Parts Measurements
To measure the distance to or shape of transparent targets using non-contact fi beroptic sensors.
29_Reflection Interference
Guidance on avoiding reflection interference when mounting fiber optic probe tips near sidewalls or adjacent probes. Covers numerical aperture, beam angle by fiber type, target spot size, and minimum spacing calculations for Philtec sensor models.
V6N1_Measurements To Glass
A manufacturer of medical equipment needed to automate a manual process of aligning their glass encoder disc to a drive motor hub.
37_Gamma Radiation Effects
Documents degradation of standard glass fibers under gamma radiation exposure with cumulative dose charts. Introduces radiation resistant synthetic fused silica fibers rated to 10^8 rad and connectorized system designs to minimize RadHard fiber cost.
Manufacturing
60_Long Cables
Reference table of maximum continuous cable lengths by sensor model. Covers one-piece, in-line connector, vacuum passthru, extension cable, and bulkhead connector system configurations for extending fiber optic cable reach.
57_90 Degree Probes
Overview of 90° probe tip styles (T4, T5, T6, T7) for side-viewing measurements where perpendicular mounting is required. Includes LC and LT dimension requirements and examples of custom right-angle probe configurations.
68_Cable Connector Options
Catalog of Philtec in-line connector options: standard Option B finger-tight, Option Bw wrench-tight for high vibration, Option B1 bulkhead, and vacuum passthru variants. Notes bandwidth and noise tradeoffs with connectorized systems.
69_FIBER OPTIC CABLE JACKETS
Reference guide to cable jacket options (PVC/monocoil, interlocking stainless steel C1, silicone-fiberglass C2/C3, PTFE C6/C7, polyolefin C11, and more). Covers temperature range, bend radius, vacuum compatibility, MRI compatibility, and crush resistance.
MRI
28_Fiberoptics For High Magnetic Fields
By jacketing the fiberoptic cable in non-metallic materials and constructing the sensor tip from non-metallic or non-magnetic materials, Philtec sensors can be configured to perform measurements in very high magnetic fields. Successful applications in environments of several Tesla have been reported.
70_Magnetic Fields
Configuration guide for fiber optic sensors in multi-Tesla magnetic fields using non-metallic cable jackets (C3, C6, C7, C8, C11) and non-magnetic probe tips (PEEK, Torlon, brass, aluminum). Includes example MRI and superconducting magnet applications.
Energy & Turbo Machinery
59 Turbine Blade Tip-to-Casing Clearance
Fossil power generation gas and steam turbine manufacturing companies have long used hand-held feeler gages to measure the blade tip clearances and inspect the roundness of the TBC linings at access ports provided for that purpose. With new construction and at overhaul, turbine blade tip-to-casing clearances at room temperature must be properly set.
78_Turbine Speed Probe
A Ø 1.5 mm test probe was made with the fi bers polished to a 30° angle. The emittted light beam was observed to spread over a 50° angle
83_Wifi Sensors
Experience the next generation of precision measurement with Philtec’s new WiFi Displacement Sensors. Designed for maximum flexibility, these wireless systems deliver accurate non-contact gap and angle data without the constraints of traditional cabling.
Vacuum & UHV
V9N3_MeasureInVacuum
Philtec provides a unique line of vacuum passthru hardware that enables measurements from low vacuum to UHV applications.
74_VACUUM PASSTHRU HARDWARE
Product overview of Philtec vacuum passthru hardware for low vacuum through UHV and outer space applications. Summarizes vacuum ratings, single/dual channel options, and hardware models for D and RC sensor types.