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.
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.
Fiber Optic Fundamentals
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.
Threaded Tips
The specifications listed represent our standard offerings with fixed pricing. If your application requires a custom thread diameter or a non-standard length, please submit a Request for Quotation (RFQ) to our factory for a custom manufacturing assessment.
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.
Reflectance Dependency
Explains how D-type fiber optic sensors produce output proportional to both distance and target reflectance. Covers near-side vs far-side operation, in-situ calibration for different materials, and when D-type sensors are recommended for single-axis vibration with constant reflectivity.
Reflectance Compensation
Describes RC (Reflectance Compensated) sensors that use ratiometric processing of two detector channels to measure distance independently of target reflectivity. Ideal for rotating, translating, or varying-surface targets such as bearing dynamics and in-process dimensional control.
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.
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.
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).
FO Sensor System Configurations
Overview of four Philtec sensor system architectures: one-piece integrated, two-piece with in-line or bulkhead connector, three-piece vacuum passthru, and three-piece extension cable systems. Reference for specifying connector and amplifier layouts.
Type D Sensors with Tilt
Sensor selection guidance when probe mounting cannot be perpendicular to the target or when cantilever targets rotate during deflection. Compares numerical aperture (66°, 30°, 25°) models and tilt sensitivity across D-type sensor families.
Aerospace
Radiation Resistant Sensor Systems
Guidance on RadHard fiber optic sensor systems for space and high-radiation environments. Covers connectorized designs to minimize costly RadHard fiber length, stainless steel and PEEK jacketing, and MIL-PRF-49291 certified fiber options.
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.
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.
Cryogenics
Pressurized Cryogenic Fluids
Philtec experience with fiber optic displacement sensors in LOX/methane rocket engine turbopump testing. Documents operating conditions in liquid hydrogen, liquid oxygen, and liquid methane at cryogenic temperatures and pressures up to 7500 psi.
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.
Sensors for Extreme Environments
October 2007 e-newsletter case study: three mini-DMS sensors for a 4K cryogenic imaging system measuring gap between a superconducting magnetic sensor and vacuum window. Custom brass tips, Teflon sheathing, and Fv2 vacuum feedthru in high magnetic field.
Glass
Contoured Glass Inspection
Multi-probe fiber optic system for inspecting contoured automotive glass panels for conformance to master shape ±50 μm. Covers single-sided measurement, back-side reflection effects, painted vs clear glass, and perpendicular calibration fixturing.
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.
Option R – Ambient Light Rejection
Describes Option R1 narrow-bandpass filter that reduces or eliminates interference from overhead lighting, fluorescent lamps, and visible-spectrum sources. Matches 850 nm LED emission to photodiode spectral response for cleaner measurements.
Custom Applications
Showcase of custom Philtec sensor solutions: soil testing shear strain, drilling fluid viscometers, bi-metallic thermostat snap detection, precision gear testing, semiconductor wafer chuck leveling, and other customer-specific probe designs.
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.
Intrinsic Safety with Fiberoptics
Dual-channel 2DMS-D100 system with 39–49 ft intrinsically safe fiber optic cabling for gap measurement between rollers in combustible solvent-based fabric coating production. Electronics located safely away from hazardous atmosphere.
68_Connectors
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_FO 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
Gap Sensors for MRI Applications
Overview of Philtec fiber optic displacement sensors used in the 11.7T Iseult whole-body MRI prototype at CEA-Saclay. Documents sub-micron displacement measurement of superconductor and magnet structures in liquid helium at 1.8K and 11.7T magnetic field.
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.
Vacuum
Multi-Channel Vacuum Passthru BvF
Describes BvF multi-channel vacuum passthru flange assembly rated to 10^-7 Torr using fused fiberoptic glass rod. Supports up to 8 D-model or 5 RC-model sensor channels through a single 160 mm flange.
Vacuum 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.