SM SC 2 Jumper Set Reference скачать в хорошем качестве

SM SC 2 Jumper Set Reference

Before testing or troubleshooting your installed fiber optic cables, make sure you subtract the losses from your test cables so you don't introduce extra losses into your fiber optic cable link. Here's what I mean... let's say you are about to troubleshoot, or test, a fiber optic cable. You connect your tester to a patch panel using a test cable. When your tester sends a light source through your test cable and through the installed cable to the other end, your remote tester will read losses as a result of both your test cable and the installed cable. The set reference procedure first measures the light loss from the test cable, subtracts that loss as a reference, so that when you test your installed cable, you are only reading losses as a result of the installed cable. In this video, Softing will show you how to set reference using the 2-jumper set reference procedure. You will see a diagram of a 1-jumper, 2-jumper, and 3-jumper set reference, and we will discuss single direction and bi-directional set reference. With all set references, there is a tradeoff. 1-jumper set reference is the TIA preferred method. This method only subtracts losses from one test cable, which is good. That means the second test cable, on the remote side, will include losses in your final test results, which is bad. However, this method subtracts the least from your final certification test, which overall, is the safest method for your customer. 2-jumper set reference is perhaps the most convenient in the field. If you use the 2-jumper method in your certification testing, just make sure this is acceptable in the project scope. This method subtracts losses from both test cables, which is great. The downside is there was a coupler in the middle while performing set reference. Those losses were subtracted too. But this coupler isn't being used in the final test, which means more losses were subtracted from your cable than should be, which is bad (which means you'll have a tighter margin while testing, which is good for your customer). Since there is a max acceptable subtraction during set reference, this keeps you from subtracting too much, which is good. 3-jumper set reference is only going to be required when you have a mixed cable -- a mixed cable means a permanent link (cable) installed with two different types of connectors on each end of the cable. There's just no way around it. Note about fiber cleaning: You will see fiber cleaning in this video because this is always part of a fiber test. Why clean your fiber end face? First, because this eliminates over 90% of fiber problems. Second, because if there is dirt on the transmit end face, when you connect the cable, you could grind the dirt into the glass of the end face which will permanently damage the end face. Note about dBm. dBM is absolute power. For example 0 dBm is 1mW of power. As the dBm value becomes more negative, the power is less (in our case, usually due to attenuation, that is, length of cable, dirty end faces, etc). Every time you drop by 3dBm, this corresponds roughly to half the power. For example, a value of -3dBm is about 0.5mW. And -10dBm is 0.1mW. If you are measuring the signal at the far end of the cable, more attenuation will cause you to have a more negative dBm absolute power level value. Note about dB. dB is a ratio. Since dB is a ratio, meaning one value divided by another value, the unit of measure is dimensionless. dB is normally used as an expression of signal to noise, that is a ratio of signal to noise. For example, if you have 1mW of power and 1mW of noise, you have 1dB signal to noise ratio, which is as much signal as you have noise, which is bad.