Overview
Feasa Optical Heads are precision-engineered measurement receptacles designed to sit between the LED under test and the Feasa LED Analyser fibre. Their compact, robust design compensates for small variations in LED placement — delivering consistent, repeatable readings with less than 10% intensity change over a 1mm LED offset. They also reduce sensitivity to ambient light, which is critical in production environments.
The Feasa Optical Head range covers LED centre-to-centre distances from 1.1mm (ultra-tight headlight arrays) to 13mm (large-diameter LEDs), with specialised variants for high-brightness applications, 90° emitting LEDs, RF environments, infrared LEDs, high-temperature oven use and low-light backlit panels. All standard heads are designed to press-fit into a G10 PCB drill hole, with the fibre connecting them to the Feasa LED Analyser.
The typical gap between the LED under test and the Optical Head is 3–5mm, though this varies with application. Feasa continues to develop new Optical Head designs for emerging applications — contact us if you require a configuration not listed here or need advice on fixture design.
Precision optical coupling for every application.
<10% intensity variation over 1mm offset
The Optical Head compensates for small variations in LED placement — where a fibre alone would show significant intensity fluctuation. Delivers consistent readings from fixture to fixture and cycle to cycle.
1.1mm to 13mm centre-to-centre coverage
From ultra-tight headlight matrix arrays (OH-11, 1.1mm C/C) to large-diameter LEDs (OH-30, 13mm C/C) — the range covers the full spectrum of LED geometries found in automotive, industrial and consumer electronics production.
Specialised variants for every application
90° versions for side-emitting LEDs, RF-rated heads for EMC environments, high-temperature heads for oven use (−65°C to +125°C), IR-specific heads for the IR Analyser, and 2.2mm fibre heads for low light and RGB applications.
40+ years expertise
Engineering LED test solutions since the early 2000s, headquartered in Limerick, Ireland.
Custom design available
Feasa can provide specialised customer solutions for applications not covered by the standard range. Contact the engineering team for advice on custom optical head design and fixture integration.
ISO 9001 certified
Full in-house design, development and manufacturing. Deployed in 30+ countries worldwide.
Choosing an optical head
A quick guide to selecting the right head for your application.
Standard production LED testing
OH-3 is the most widely used — 5mm centre-to-centre, standard intensity. Suitable for the majority of indicator, automotive interior and consumer electronics LED test applications.
Automotive headlights & matrix LEDs
OH-10 and OH-11 for tight headlight arrays (1.1–1.5mm C/C). OH-6, OH-23, OH-26, OH-33 for high-brightness applications. OH-10G for headlight LEDs in thermal environments.
Backlit switches & RGB panels
OH-12, OH-13, OH-14 family (2.2mm POF) for Low Light and RGB Analyser applications — backlit switches, lightguides and panels where light passes through etched or painted plastic.
Special environments
OH-7LT / 17LT / 10G for Life Tester oven use (−65 to +125°C). OH-8IR / 8A-IR for IR LED testing. OH-9RF / 19RF for RF test environments. OH-7D for dual-fibre custom applications.
Spécifications complètes
1mm Plastic Optical Fibre (POF) — Standard visible LED analysers
| Référence | Entraxe min. | Fibre | Plage de température | Utilisation / remarques |
|---|---|---|---|---|
| OH-21 | 2.8mm | POF 1mm | 0–70°C | Standard intensity. Fibre glued in place. |
| OH-1 | 3.5mm | POF 1mm | 0–70°C | Standard intensity LEDs |
| OH-1A | 3.5mm | POF 1mm | 0–70°C | High intensity LEDs |
| OH-24 | 3.5mm | POF 1mm | 0–70°C | 90° / side-emitting |
| OH-5 | 4mm | POF 1mm | 0–70°C | Standard intensity LEDs |
| OH-3 | 5mm | POF 1mm | 0–70°C | Standard — most common head |
| OH3-RGB | 5mm | POF 1mm | 0–70°C | RGB LED test |
| OH-23 | 5mm | POF 1mm | 0–70°C | Super high brightness |
| OH-33 | 5mm | POF 1mm | 0–70°C | High brightness |
| OH-9RF | 7mm | POF 1mm | 0–70°C | RF test environments |
| OH-6 | 9mm | POF 1mm | 0–70°C | High brightness / large LED |
| OH6-RGB | 9mm | POF 1mm | 0–70°C | RGB LED test, 8mm body |
| OH-26 | 9mm | POF 1mm | 0–70°C | Super high brightness |
| OH-30 | 13mm | POF 1mm | 0–70°C | Large diameter LED |
| OH-10 | 1.5mm | POF 1mm | 0–70°C | High brightness headlights / tight pitch |
| OH-11 | 1.1mm | POF 1mm | 0–70°C | High brightness, very tight pitch |
| OH-7D | 5mm | Optional dual | 0–70°C | Dual fibre — custom application |
1.1mm Glass Optical Fibre — Infrared Analyser and Life Tester
| Référence | Entraxe min. | Fibre | Plage de température | Utilisation / remarques |
|---|---|---|---|---|
| OH-8IR | 5mm | Glass 1.1mm | 0–70°C | Standard IR LEDs — use with IR Analyser |
| OH-8A-IR | 5mm | Glass 1.1mm | 0–70°C | High brightness IR LEDs |
| OH-7LT | 5mm | Glass 1.1mm | −65 to +125°C | Standard intensity — use with Life Tester |
| OH-17LT | 5mm | Glass 1.1mm | −65 to +125°C | RGB LED test — use with Life Tester |
| OH-10G-xxx | 1.5mm | Glass 1.1mm | −65 to +125°C | High brightness glass fibre — Life Tester or IR |
2.2mm Plastic Optical Fibre (POF) — Low Light and RGB analysers
| Référence | Entraxe min. | Fibre | Plage de température | Utilisation / remarques |
|---|---|---|---|---|
| OH-12 | 5mm | POF 2.2mm | 0–70°C | Short (OH-13) — fibre glued in place |
| OH-13 | 5mm | POF 2.2mm | 0–70°C | Low Light standard head — fibre glued |
| OH-14 | 5mm | POF 2.2mm | 0–70°C | 90° — for side-emitting low light LEDs |
| OH-16 | 11mm | POF 2.2mm | 0–70°C | Large LED / backlit panel |
| OH-31 | 13mm | POF 2.2mm | 0–70°C | Large diameter LED |
Downloads and Resources
Optical Head Datasheet
2025 Catalogue
Custom enquiry
LINK