OP940 Optical Return Loss Meter and Insertion Loss Meter
The Industry’s fastest & most accurate Optical Return Loss Meter
Making your fiber cable assemblies and products with the HIGHEST quality is faster, easier and more efficient with our OP940 Single Optical Channel Return Loss and Insertion Loss Tester. This tester is an extremely important component in R&D, labs or production manufacturing lines where your customers/end users demand the very highest performance from your products.
The OP940 is used around the globe in R&D, Labs, and cable production manufacturing. This single channel optical return loss meter comes in both desktop and 19″ rackmount sizes.
To test multi-channel fiber optic cable assemblies, pair it with our OP720 Optical Switch for 4-148 channel fiber cables.
Looking to test your fiber cables and products in both directions, add our OP725 Bi-Directional Switch for superfast 6 second tests of a simplex cable for two wavelengths in both directions (See it in action – video)..
FAST
ACCURATE
RELIABLE
FEATURES & BENEFITS
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Robust and Intuitive Front Panel
The user experience through the front panel of the OP940 is simple and easy to navigate without sacrificing functionality. Test IL and RL simultaneously with results updating in real time. Adjust the RL reference position and measure both front and back connectors. Set pass/fail criteria and engage the colored display to quickly verify a batch of cables. If you’re ever unsure of what to do, help menus are accessible on every screen to guide you through the different features and options.
Identify and Fix Issues with Minimal Downtime
Minimize your production downtime by identifying and troubleshooting issues right through the front panel. Use the optical reflectance trace to find reflections along the optical path caused by dirt or misaligned connectors. If there is a reflection at the front panel, you can remove it to access the connector and perform maintenance without exposing the rest of the unit to the elements.
Wide Dynamic Range for RL Measurements
By making use of a wide dynamic range (SM, FTTX: -10dB to -80dB | MM: -10dB to -58dB) for RL measurements, the OP940 can adjust for attenuation in the reference setup, which results in the most accurate RL results in the industry.
Fastest IL/RL Measurement
Utilizing the OP940, you can test a single channel, dual wavelength, IL and RL in less than 4 seconds.
Customizable
The OP940 is available with SM, MM, and FTTX wavelengths and a variety of core sizes and detector options to meet your needs.
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MADE IN THE USA
We proudly design & manufacture our equipment in California, United States.
- Test Insertion Loss and Return Loss in Seconds
- Set Return Loss Reference Position and Value
- Measure Return Loss at Multiple Connection Points through the Front Panel
- Produce Cable Test Reports or Labels through Software
- Programmable Pass/Fail
- Available in Single Mode, Multimode, FTTX
- On Screen Help
- Easy to Use
APPLICATIONS
MANUFACTURING TESTING
R&D TESTING
SOFTWARE
Automate, customize, and record your tests through software.
CALIBRATION
Can be calibrated on-site, in-house or remotely.
3-YEAR WARRANTY
OptoTest offers a three-year full warranty!

DOWNLOADS
TECH SUPPORT
Our team of experts is ready to assist you.
30-DAY GUARANTEE
Our 30-Day Guarantee allows a full refund for any reason.
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Talk to one of our sales engineers at +1(805) 987-1700 to learn more about our custom solutions.
PRODUCT RESOURCES
Return Loss | Single Mode | FTTX | Multimode | ||
Source Wavelength | 1310nm, 1550nm | 1310nm, 1550nm, 1490nm, 1625nm | 850nm, 1300nm | ||
Calibrated Measurement Range |
-10dB to -80dB | -10dB to -80dB | -10dB to -58dB | ||
Measurement Linearity | ±1dB (-12dB to -72dB) | ±1dB (-12dB to -72dB) | ±1dB (-10dB to -45dB) | ||
Distance Range | up to 2500 meters | ||||
Mandrel-free minimum distance | 1.7 meters (both reflections <-45dB) | ||||
Insertion Loss | Single Mode | FTTX | Multimode | ||
Source Center Wavelength | ±30nm from nominal | ±30nm from nominal | ±30nm from nominal | ||
Source Bandwidth | <10nm | <10nm | <140nm (850nm) <200nm (1300nm) | ||
Internal Fiber | 9/125μm (SMF28) | 9/125μm (SMF28) | 50/125μm, 62.5/125μm, 105/125μm | ||
Launch Condition | N/A | N/A | Available upon request | ||
Output Power* (typical) | -1.5dBm | -2.5dBm | -18dBm(850nm) -20dBm(1300nm): 62.5/125μm |
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Insertion Loss Stability** | ±0.02dB | ±0.02dB | ±0.02dB | ||
Measurement Linearity (Relative Accuracy)*** |
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Deviation ± 0.05dB | 0dBm to -65dBm at 1490nm | ||||
Deviation ± 0.01dB | <10dB power variation |
*For single channel systems. **Over 1 hour with a max. change of 1ºC. ***For 1, 2, and 3mm detectors.
Measurement Timing | Single Mode | FTTX | Multimode |
IL and RL, Dual Wavelength | 3s* | 6s | 3s* |
Switching Time (Multichannel) | 100ms |
* Using the front panel in Dual ILRL mode or running OPL-Pro with real-time update enabled.
Mainframe | OP940 | |||
Dimensions | 8.5” x 3.5” x 12″ | |||
Power Supply | 90VAC … 264VAC; 47Hz to 63Hz; 0.7Amps (115VAC) 0.4Amps (230VAC); Fuse: T1A, 250V | |||
Warm-up time | 5-15 minutes | |||
Operating Temperature | 5℃ to 40℃ | |||
Maximum Relative humidity* | 95% |
* For temperatures up to 31°C, decreasing linearly to 50% relative humidity at 40°C.
Government Contractor?
COMMON TESTING CONFIGURATIONS
Duplex LC IL/RL

Simplex FC IL/RL

12 Channel MTP Bidi IL/RL
