Month: December 2013

Find Hidden Cables with Cable Wire Locators

Locating buried and hidden lines prior to construction or maintenance projects is critical to ensure the safety of your crew and reducing the potentially costly mistake. Cable locators and wire tracers are specially designed to aid in locating energized and de-energized wires, cable and pipes whether underground or hidden in a wall.

Cable locators are reply on the target having a charge or signal placed on them which is detected by a receiver within the locator, many locators are able to induce a signal onto the line using a transmitter in order to find it. Generally, the target must be metallic in order to conduct the signal, through a sonder or mini-transmitter can be used with plastic pipes. When induce a signal onto a pipe or cable, the transmitter is most commonly connected directly to the line or pipe to be located using signal clamps or clips. The signal will then transmit along the pipe or cable. In areas where there is no access to the line, the transmitter can also induce a signal from above, through the gourd to reach the utility.

Depending upon the application, there is a range of cable locators to be chosen. Some are designed for use for underground lines and pipes while other better suited for the tight confines of a walllikes wire trackers. Cable locators usually include a transmitter and a receiver. A widely used underground cable wire locator is NF-816, which is designed to locate the path of none-energized wirebehind walls or underearth. It can rapidly find the target wire from among plenty of telephone wires or network wires. By comparing the volume of the “tout” sound and the brightness of the signal indicator, you can find the target wire which has the highest volume and brightest indicator.

There are two primary methods of sweeping for lines and pipes with a cable locator: Passive locating involves sweeping an area looking for unknown lines while actively locating searching for a specific line by using either a direct connection or by inducing a signal. When using a cable locator to find underground lines and pipes, the underearth condition has a significant impact on the signal. Lays and camp solids help the signals travel down the line or pipe stronger with less interference than dry soils. So it is necessary to add water to the ground near the transmitter to improve signal strength.

Using Fiber Optic Attenuators to Increase Bit Error Rate

Fiber optic systems transmission ability is based on the optical power at the receiver, which is reflect as the bit error rate, BER is the inverse of signal-to-noise ratio, high BER means poor signals to noise ratio. Too much power or too litter power will cause high bit error rates.

When the power is too high as it often is in short single-mode systems with laser transmitters, you can reduce receiver power with an fibre attenuator. Attenuators can be made by introducing an end gap between two fiber, angular or lateral misalignment, poor fusion splicing, inserting a neutral density filter or even stressing the fiber. Both variable and fixed attenuators are available.

Variable attenuators are usually used for margin testing, it is used to increase loss until the system has high bit error rate. Fixed attenuators may be inserted in the system cables where distances in the fiber optic link are too short and excess power at the receiver causes transmission problems.

Generally, multimode systems do not need attenuators. Multimode source, even VCSELs, rarely have enough power output to saturate receivers. Single mode system, especially short links, often have too much power and need attenuators. For a single mode application like analog CATV systems, the return loss or reflectance is very important. Many types of attenuators suffer from high reflectance, so they can adversely affect transmitters just like highly reflective connectors.

Attenuators can be made by gap loss, or a physical separation of the ends of the fibers, including bending losses or inserting calibrated optical filters. Choose one type of attenuator with good reflectance specifications and always install the attenuator at the receiver end of the link. It is very convenient to test the receiver power before and after attenuation or while adjusting it with your fiber optic meters at the receiver, plus any reflectance will be attenuated on its path back to the source.

When testing the system power, turn on the transmitter, install the attenuator a the receiver, use a fiber optic power meter set to the system operating wavelength. Check to see whether the power is within the specified range for the receiver. For accurate measurements, the fiber attenuators connector types much match the lanch and receive cables to be tested, e.g. LC fibre optic attenuators is needed to work with the LC fiber patch cable, it work in 1250-1625nm range with optional attenuation value from 1dB to 30dB.

If the appropriate attenuators is not available, simply coil some patch cord around a pencil while measuring power with your fiber optic power meter, adding turns until the power is in the right range.

Using Fiber Optic Power Meter to Test Optic Power Level

Fiber optic communication equipment is based on the optical power level between the transmitter and the receiver. The difference of the optical power level between them is the loss of the cabling plant. To measure the power loss of them, an optical power meter is needed to conduct a power loss testing.

A fiber optic power meter is typically consist of a solid state detector, signal conditioning circuitry and a digital display of power. To interface to the large variety of fiber optic connectors in use, some form of removable connector adapter is usually provided. The power meter is calibrated at the same wavelength at the source output such as multimode 850 or 1300nm, single mode, 1310, 1490 and/or 1550nm, POF. Meters for POF systems are usually calibrated at 650 and 850nm. The wavelengths used in POF systems.

When performing the test, use the optical power meter adapter to mate to the connector type on the cable. The connectorized reference patch cables must be the same fiber type and size as the cable plant and have connectors compatible to those on the source and cables.

Power meters are calibrated to read in dB reference to one milliwatt of optical power. Some meters of a relative dB scale also, useful for loss measurements since the reference value may be set to 0 dB on the output of the test source. Occasionally, lab meters may also measure in linear units like milliwatts, microwatts and nanowatts.

Optical Power Testing Procedure:
Turn on the power meter to allow time to warm-up.
Set meter to wavelength of the source and “dBm” to measure calibrated optical power.
Clean all connectors and mating adapters.
Attach reference cable or fiber patch cord to source if testing source power or disconnect cable from receiver.
Attach power meter to end of cable and read measured power.

To reduce the measurement uncertainty, you must calibrate the optical power meter according the manufacturers specified intervals. Clean all connectors and remove the meter adapter periodically to clean the adapters and power meter detector. To avoid the stress loss, please don’t bend the fiber optic cables during the testing.

Optic power testing is only one the main part of fiber optic testing. Most test procedures for fiber optic component specifications have been standardized by national and international standards which are converted in procedures for measuring absolute optical power, cable and connector loss and the effects of many environment factors such as temperature, pressure, flexing, etc. Basice fiber optic testing instruments are the fiber optic power meter, optical light source, OTDR and fiber inspection microscope.

Fiber Optical Faceplate Wiki

A fiber optic face plate is a coherent multi-fiber plate, which acts as a zero-depth window, transferring an image pixel by pixel (fiber to fiber) from one face of the plate to the other. Fiber optic faceplates can be applied in FTTH access network, telecommunication networks, CATV networks, data communication networks, which is used to bring fiber to the desk and can be widely used in multi-floor and high buildings. The fiber optic faceplate can be sometime called fiber wall jacks which are available with LC. SC, ST, FC fiber optic adapters, the port number is usually 2, 3 or 4 ports.

Generally, fiber optic wall plates can be divided into three types which is bevel fiber optic plate, hybrid fiber faceplate, FTTH fiber faceplate:

The bevel fiber wall plate is with 45 adapter plug- in/out angle, Hybrid fiber optic faceplate means the fiber adapter types are different from each other which can be SC-ST, SC-ST-LC, or
SC/ST/FC/LC, each adapter style is for one port.

Common Features of bevel fiber wall plate and hybrid fiber optic faceplate includes:
Size is 86*86mm
ABS plastic material
No additional insertion loss, simple operation, low construction intensity
The snap-in module is easy to install with straight tip style fiber optic connector
All fiber adapters are “universal” to support either multimode or single mode fiber connectors

Application:
FTTH access network
Telecommunication Networks
CATV Networks
Data communications networks

Except these two types, there is also another type which is the FTTH fiber optic faceplate, which is mainly designed for applications of FTTH, FTTB, FTTC, telecommunication networks and CATV4,Local area network. Check out some features of these FTTH fiber optic faceplate.
Indoor or outdoor rated
Available in 1×4, 1×8, 1×16 splitter as well as 2×4, 2×8, 2×16 splitter
Max. Up 16pcs of FTTH drop cable or pigtails
Suitable for wall-mounting or pole mounting application

Fiber wall plate is also used to create a fiber optic network at home. Besides the switches between different floor, fiber wall plate/jack and the pre-terminated fibers are needed. Look at the specs for the optical port on the switch. If the optical port is a pluggable device, you need to get its P/N and look up the spec. Most of the fiber sold on FiberStore that is conecterized, is patch chords. Fiber patch cord has very little strain relief in them. So take care when you pull them in your new installation that you do not damage them.

CWDM Solutions Offered by FiberStore

As broadband has unveiled a new world for subscriber, full of advanced capabilities and faster speeds. Your challenge is to meet their demands without compromising your budget. Because of its distance, speed and bandwidth potential, fiber optics has become the choice for many service providers. Fiber optic connections typically requires two strands of fiber – one for transmitting and one for receiving signals. But how to do if you need to add services or customers, but you’ve exhausted your fiber lines?

Thanks to CWDM, coarse wave division multiplexing (CWDM) is a method of combining multiple signals on laser beams at various wavelengths for transmission along fiber optic cables. The number of channels is fewer than in dense wavelength division multiplexing (DWDM) but more than in standard WDM.

CWDM has many advantages over DWDM technology in terms of system costs, set-up, maintenance, and scalability. CWDM is a technology which multiplexes multiple optical signals on a single fiber optic stand by using different wavelengths, or colors, of laser light to carry the different signals.

Typical CWDM solutions provide 8 wavelengths capacity enabling the transport of 8 client interface over the same fiber. However, the relatively large separation between the CWDM wavelengths allows expansion of the CWDM network with an additional 44 wavelengths with 100GHz spacing utilizing DWDM technology, thus expanding the existing infrastructure capacity and utilizing the same equipment as part of the integrated solution.

A single outgoing and incoming wavelength of the existing CWDM infrastructure is used for 8 DWDM channels multiplexing into the original wavelength. DWDM Mux Demux and optical amplifier if needed.

The typical CWDM spectrum supports data transport rates of up to 4.25Gbps, CWDM occupies the following ITU channels: 1470nm, 1490nm, 1510nm, 1530nm, 1550nm, 1570nm, 1590nm, and 1610nm, each separated from the other by 20nm. PacketLight can insert into any of the of the 4 CWDM wavelengths (1530nm,1550nm,1570nm and 1590nm), a set of additional 8 wavelength of DWDM separated from each other by only 0.1nm. By doing so up to 4 times, the CWDM network capability can easily expand by up to 28 additional wavelengths.

With FiberStore’s compact CWDM solutions, you can receive all of the above benefits and much more (such as integrated amplifiers, protection capabilities, and integration with 3rd party networking devices, etc.) in a cost effective 1 U unit, allowing you to expand as you grown, and utilize your financial as well as physical resources to the maximum. FiberStore provides all the component involved in the process, such CWDM MUX DWMUX, CWDM OADM, even CWDM SFP transceivers.