Loss Test Set (OLTS)
Optical Loss Test Set (OLTS) includes both a meter and light source used to measure insertion loss of installed cable plants or individual cables. Also known as Light Source and Power Meter (LSPM.). The purpose is to measure the optical loss of a fiber or cable run. Multimode and single mode fiber are measured at different wavelengths. The loss measured as compared to the loss budget which is usually calculated prior to installation.
In Optical Loss Test Set (OLTS) may comprise of a light source and optical power meter is one handheld unit, or separate light source and power meter. The OLTS simulates the optical network hardware to test the performance of the installed fiber optic cable plant.
The difference between the power coupled into the cable at the transmitter and what comes out at the receiver end is the cable loss. Also called "insertion loss" testing requires measurement of the optical power lost in a length of cable. Fiber attenuation, connector loss, and splice loss other contributing factors.
Loss testing is done at the wavelengths appropriate for the fiber type and its usage. Multimode fiber is generally tested at 850 nm, and optionally at 1300 nm with LED sources. While single-mode fiber is tested at 1310 nm and optionally at 1550 nm with a laser optical source. The total measured loss is compared to the calculated estimated loss known as "loss budget".
Another consideration with OLTSs these type of fiber optic connectors adapters needed for the unit. FC, ST, and SC fiber-optic connectors are widely used, but there are more than a dozen less-popular devices in use. A new generation of small-form-factor fiber-optic connectors has been recently introduced and gaining popularity.
To determine end to end loss measurements of fiber optic system. OLM consists of two units.
- Light source.
- Power meter.
Application of Power Meter & Light Source ( OLM )
- Power Meter is used for checking continuity.
- Transmit power level and measure receive power.
- End to end performance is tested on power meter and light source.