Did You Know....

There's an easy way to update your transmission system to improve reflectance? / March-April 2017

Are your fibers terminated with connectors that don’t meet current optical return loss and reflectance values? New transmission systems often require lower reflectance levels to meet the desired bit error rate.
In the 1990s, connectors used either physical contact (PC) or super physical contact (SPC) spherical polishes. PC polishes had a reflectance level of 40 dB and SPC polishes were approximately 45 dB.  Today, the ultra physical contact (55 dB) and angled physical contact (65 dB) polishes are 10 to 100 times better in regards to the amount of light reflected.
There are several alternatives to improve the reflectance levels of the connectors in your network. You can choose to replace the pigtail, or to use the new generation of splice-on connectors.  These splice-on connectors have low loss, meet either UPC or APC polish levels, and come in either mechanical or a fuse-on styles. They provide an option for simple and cost-effective upgrades that address only the fibers that need improved reflectance levels.

Winter is hard on us and our test equipment? / January-February 2017

Extreme temperatures, both cold and hot, affect both technicians and their test equipment. Job sites may be thermally regulated, which is good. But technicians need to remember their optical and electrical test equipment rode over in the vehicle with them. Leaving equipment in a vehicle overnight exacerbates the issue.

Test measurements are impacted by thermal changes in the test instruments themselves. Thus, bringing test instruments stored overnight in a vehicle into a test environment kept at a different temperature can contribute to measurement errors. Think of equipment stored in a van overnight at -10°F (-23°C) entering into an equipment room kept around 65°F (18°C). This is a 75°F (41°C) temperature delta. You feel it when walking in/out.

Test equipment can take an hour or more to fully adjust and stabilize at the new ambient temperature. Features like protective rubber boots and padded carry cases further insulate the instrument slowing down the thermal adjustment. An instrument may feel room temp to touch, but this is the outside layer of the case. The temperature of important inside electronics and optics will adjust slower.

Hot and cold weather must be dealt with. To improve your odds of making best measurements use setup time to your advantage. Make bringing fiber optic or electronic test gear onto the job site one of the first priorities. Immediately take it out of carry cases and spread test instruments out to let them begin adjusting to the new temperature. Leave them there while you go about the rest of the job setup.

It is best to power up instruments 15 to 20 minutes ahead of test time to further let things warm up and stabilize. For optical loss test kits, set references prior to making measurements with the power meter and source in the test environment and after warm up. These simple planning steps will provide improved (more consistent) test results.

Contributed by Don Allard, AFL Test & Inspection


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