physics

Line splice

Line splice is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Line splice rather than just read about it. In short: In electrical engineering and telecommunications, a line splice is a joint directly connecting lengths of electrical cables (electrical splice) or optical fibers (optical splice). The splices are often protected by sleeves.

Key takeaways

Line splice belongs to physics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Line splice to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Line splice from memory before moving on to harder problems.

Reference excerpt

In electrical engineering and telecommunications, a line splice is a joint directly connecting lengths of electrical cables (electrical splice) or optical fibers (optical splice). The splices are often protected by sleeves.

Splicing of copper wires

The splicing of copper wires happens in the following steps:

The cores are laid one above the other at the junction. The core insulation is removed. The wires are wrapped two to three times around each other (twisting). The bare veins on a length of about 3 cm "strangle" or "twist". In some cases, the strangulation is soldered. To isolate the splice, an insulating sleeve made of paper or plastic is pushed over it. The splicing of copper wires is mainly used on paper insulated wires. LSA techniques (LSA: soldering, screwing and stripping free) are used to connect copper wires, making the copper wires faster and easier to connect. LSA techniques include:

Wire connection sleeves (AVH = Adernverbindungshülsen) and other crimp connectors. The two wires to be connected are inserted into the AVH without being stripped, which is then compressed with special pliers. The about 2 cm long AVH consist of contact, pressure and insulation. For wire connection strips (AVL = Adernverbindungsleisten) several pairs of wires (10 = AVL10 or 20 = AVL20) are inserted, the strip is then closed with a lid and pressed together with a hydraulic press, which ensures the connection.

Splicing of glass fibers

Fiber-optic cables are spliced using a special arc-splicer, with installation cables connected at their ends to respective "pigtails" - short individual fibers with fiber-optic connectors at one end. The splicer precisely adjusts the light-guiding cores of the two ends of the glass fibers to be spliced. The adjustment is done fully automatically in modern devices, whereas in older models this is carried out manually by means of micrometer screws and microscope. An experienced splicer can precisely position the fiber ends within a few seconds. Subsequently, the fibers are fused together (welded) with an electric arc. Since no additional material is added, such as gas welding or soldering, this is called a "fusion splice". Depending on the quality of the splicing process, attenuation values at the splice points are achieved by 0.3 dB, with good splices also below 0.02 dB. For newer generation devices, alignment is done automatically by motors. Here one differentiates core and jacket centering. At core centering (usually single-mode fibers), the fiber cores are aligned. A possible core offset with respect to the jacket is corrected. In the jacket centering (usually in multimode fibers), the fibers are adjusted to each other by means of electronic image processing in front of the splice. When working with good equipment, the damping value is according to experience at max. 0.1 dB. Measurements are made by means of special measuring devices including optical time-domain reflectometry (OTDR). A good splice should have an attenuation of less than 0.3 dB over the entire distance. Finished fiber optic splices are housed in splice boxes. One differentiates:

Fusion splice Adhesive splicing Crimp splice or NENP (no-epoxy no-polish), mechanical splice

See also Fusion splicing Mechanical splice Rat-tail splice T-splice Western Union splice

References

Yablonx, Andrew D. (2005). Optical fiber fusion splicing. Springer, Berlin, Heidelberg, New York. ISBN 978-3-540-23104-2.

Illustrations

Worked examples

Example 1 — a first encounter with Line splice

Start with the simplest possible case. Write down what Line splice claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Line splice before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Line splice ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Line splice

In research: Line splice appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Line splice in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Line splice is common in secondary-school and first-year university syllabi. It links to neighbouring topics Electrical wiring, Fiber optics, Industrial processes, so understanding it makes those chapters shorter.
In everyday life: Look for Line splice outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Line splice in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Line splice means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Line splice out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Line splice in simple terms?

Why does Line splice matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Line splice?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Line splice.