EXFO
EXFO ELS-50 Optical Light Source | 1310/1550nm Dual Wavelength, ±0.10dB Stability, 60-Hour Battery
EXFO ELS-50 Optical Light Source | 1310/1550nm Dual Wavelength, ±0.10dB Stability, 60-Hour Battery
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EXFO ELS-50 Optical Light Source – 60-Hour Battery, ±0.10dB Stability, 1310/1550nm
The EXFO ELS-50 is a professional dual-wavelength optical light source built for field technicians who demand reliability. With an industry-leading 60-hour battery life on standard AA batteries and ±0.10dB output stability, the ELS-50 delivers consistent, repeatable insertion loss measurements all day — no charging, no proprietary battery packs. Built-in 270/1k/2kHz tone generation and interchangeable connector adapters make it the go-to light source for FTTH, telecom, and CATV fiber testing. Pair it with the EXFO EPM-50 Power Meter for a complete, matched insertion loss test set.
Key Features
- 60-Hour Battery Life: Runs on standard AA batteries — over 2.5 days of continuous field testing without recharging or battery swaps
- ±0.10dB Power Stability: Precise, repeatable output for accurate insertion loss measurements across all test conditions
- Dual Wavelength 1310/1550nm: Tests both standard singlemode telecom wavelengths in one compact instrument (≥-5dBm output, ≥5nm spectral width)
- 270/1k/2kHz Tone Generation: Identify and trace individual fibers in multi-fiber cables without interrupting service — up to 60 hours of tone output
- Interchangeable Connector Adapters: Field-swappable FC, SC, ST, and LC adapters for maximum flexibility; FC adapter included
- Rugged Field Design: Compact 189×78×37mm body, 400g — fits in a tool bag or jacket pocket; built for demanding outdoor environments
- Perfect Pair with EXFO EPM-50: Matched form factor, same AA battery platform — complete your insertion loss test set with one trusted brand
- 1-Year Warranty with Certificate of Compliance included
Ideal Applications
- Fiber optic insertion loss testing (paired with EPM-50 power meter)
- FTTH / FTTx network installation and acceptance testing
- Telecom network construction and maintenance
- CATV fiber plant testing and troubleshooting
- Fiber identification using tone generation (270/1k/2kHz)
- Field testing requiring long battery life without charging infrastructure
Complete Insertion Loss Test Set: ELS-50 + EPM-50
The ELS-50 injects stable optical power at 1310nm or 1550nm into the fiber under test; the EXFO EPM-50 measures received power at the far end. The difference — displayed directly in dB after referencing — is the insertion loss of the link. Both instruments share the same compact form factor, AA battery platform, and EXFO FiberBasix reliability. See our EXFO EPM-50 listing to complete your test set.
Technical Specifications
| Parameter | ELS-50 (Model 23BL) |
|---|---|
| Wavelengths | 1310nm / 1550nm |
| Spectral Width | ≥5nm |
| Output Power | ≥-5dBm |
| Power Stability | ±0.10dB |
| Tone Generation | 270Hz / 1kHz / 2kHz |
| Battery Life | 60 hours (AA batteries) |
| Connector | Interchangeable adapters (FC, SC, ST, LC) |
| Dimensions | 189 × 78 × 37mm |
| Weight | 400g (0.9 lb) |
| Operating Temperature | -10°C to +50°C |
| Storage Temperature | -40°C to +70°C |
| Humidity | 0–95% non-condensing |
| Warranty | 1 Year |
Package Contents
- EXFO ELS-50 Light Source Main Unit
- AA Batteries
- FC Connector Adapter
- Quick Reference Sticker
- Certificate of Compliance
- Soft Carrying Pouch
Frequently Asked Questions
Q: What power meter pairs with the EXFO ELS-50?
A: The ELS-50 is designed to pair with the EXFO EPM-50 Power Meter for a complete insertion loss test set. Both share the same compact form factor, AA battery platform, and EXFO FiberBasix reliability.
Q: How long does the battery last?
A: The ELS-50 runs on standard AA batteries with 60 hours of continuous operation — over 2.5 days of uninterrupted field testing, eliminating the need for charging infrastructure.
Q: What connector types does the ELS-50 support?
A: The ELS-50 features interchangeable connector adapters supporting FC, SC, ST, and LC connector types. The FC adapter is included; additional adapters are available separately.
Q: What is tone generation and how is it used?
A: The ELS-50 modulates its output at 270Hz, 1kHz, or 2kHz. When used with a compatible power meter or fiber identifier, this tone allows technicians to trace specific fibers in multi-fiber cables without interrupting service.
Q: What warranty does the EXFO ELS-50 come with?
A: The ELS-50 comes with a 1-year warranty and certificate of compliance. For support or bulk pricing, contact us at info@splicermarket.com.

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