How to Measure the Fiber Optic Network by Using OTDR Testers?

Optical fiber measurement can be divided into three steps: using OTDR testers for parameter setting, data acquisition and analysis. Measuring parameters include artificial Settings.

(1) the wavelength selection (λ):

Because of different wavelengths corresponding to different features (including attenuation, slightly curved, etc.), generally following the test wavelength and wavelength corresponds to the principle of transmission communication system, the system open 1550 wavelengths, the test wavelength of 1550nm.

 

(2) Pulse Width:

The longer the pulse width, the bigger the dynamic measurement range, measurement of distance is longer, but blind area is bigger in OTDR curve waveform; Short pulse injection of low light level, but can reduce the blind area. Usually stand by ns for pulse width cycle.

 

(3) Range:

OTDR testers measurement range is refers to the maximum distance of OTDR data sampling, the choice of this parameter determines the size of the sampling resolution. Best measurement range for 1.5 ~ 2 times the distance between optic fiber network length.

 

(4) Average time:

The backward scattering light signal is very weak, generally USES the statistical average method to improve the signal-to-noise ratio, average, the longer the average time, the higher signal-to-noise ratio.

 

(5) Parameters of optical fiber

Optical fiber parameter setting including the refractive index n and Backscatter coefficient of η. Refractive index parameters related to distance measuring, backscatter coefficient effects the measurement results of reflection and return loss.

After Parameter Settings, OTDR can be sent and received by the optical fiber link light pulse scattering and reflected light, the photodetector outputs sample, get the OTDR curve, the curve is analyzed to understand quality of optical fiber.

 

Experience and skills

(1) Simple discriminant of fiber quality

Under normal circumstances, OTDR test the light curve of the subject (single or several plate cable) slope are consistent, if a certain section of the slope is bigger, indicates the period of decay; If subject to irregular shape curve, the slope is volatile, it is bent or arc, suggests that bulk fiber cables quality degradation seriously, do not conform to the requirements of the communication.

 

(2) The choice of wavelength and the test of Uni and Bi-direction:

1550 wavelengths to test distance is farther, a 1550nm – 1550nm fiber is more sensitive to bending than 1310. In an actual optical cable maintenance, compare both wavelengths to get good test results.

(3) Clean the joint:

Before accessing optical union, must be cleaned carefully, including OTDR output fiber assembly connectors and measured union, or the insertion loss will too big, otherwise don’t reliable, much noise can stop the measurement, it may also damage the OTDR. Avoid using alcohol cleaning or other refractive index matching liquid, because they can dissolve the adhesive within optical fiber connector.

 

(4) The use of additional optical fiber

Additional optical fiber is used to connect OTDR and optical fiber which under test, 300 ~ 2000 m long fiber, its main role is: the front insert measuring blind area processing and terminal connector.

 

In general, OTDR and optical fiber connectors between blind area under test is the largest. In actual measurement of the optical fiber in the OTDR with fiber and after a period of transition, the front end blind area falls within the transition of optical fiber, the fiber under test head fell on the OTDR curve in the linear region. Optical fiber system between connector insertion loss by OTDR testers and optical fiber to measure for a period of transition. As to measure the first and end connector on both ends of the insertion loss, can add a transitional fiber in every side.

How to Measure the Fiber Optic Network by Using OTDR Testers?

Optical fiber measurement can be divided into three steps: using OTDR testers for parameter setting, data acquisition and analysis. Measuring parameters include artificial Settings.

(1) the wavelength selection (λ):

Because of different wavelengths corresponding to different features (including attenuation, slightly curved, etc.), generally following the test wavelength and wavelength corresponds to the principle of transmission communication system, the system open 1550 wavelengths, the test wavelength of 1550nm.

 

(2) Pulse Width:

The longer the pulse width, the bigger the dynamic measurement range, measurement of distance is longer, but blind area is bigger in OTDR curve waveform; Short pulse injection of low light level, but can reduce the blind area. Usually stand by ns for pulse width cycle.

 

(3) Range:

OTDR testers measurement range is refers to the maximum distance of OTDR data sampling, the choice of this parameter determines the size of the sampling resolution. Best measurement range for 1.5 ~ 2 times the distance between optic fiber network length.

 

(4) Average time:

The backward scattering light signal is very weak, generally USES the statistical average method to improve the signal-to-noise ratio, average, the longer the average time, the higher signal-to-noise ratio.

 

(5) Parameters of optical fiber

Optical fiber parameter setting including the refractive index n and Backscatter coefficient of η. Refractive index parameters related to distance measuring, backscatter coefficient effects the measurement results of reflection and return loss.

After Parameter Settings, OTDR can be sent and received by the optical fiber link light pulse scattering and reflected light, the photodetector outputs sample, get the OTDR curve, the curve is analyzed to understand quality of optical fiber.

 

Experience and skills

(1) Simple discriminant of fiber quality

Under normal circumstances, OTDR test the light curve of the subject (single or several plate cable) slope are consistent, if a certain section of the slope is bigger, indicates the period of decay; If subject to irregular shape curve, the slope is volatile, it is bent or arc, suggests that bulk fiber cables quality degradation seriously, do not conform to the requirements of the communication.

 

(2) The choice of wavelength and the test of Uni and Bi-direction:

1550 wavelengths to test distance is farther, a 1550nm – 1550nm fiber is more sensitive to bending than 1310. In an actual optical cable maintenance, compare both wavelengths to get good test results.

(3) Clean the joint:

Before accessing optical union, must be cleaned carefully, including OTDR output fiber assembly connectors and measured union, or the insertion loss will too big, otherwise don’t reliable, much noise can stop the measurement, it may also damage the OTDR. Avoid using alcohol cleaning or other refractive index matching liquid, because they can dissolve the adhesive within optical fiber connector.

 

(4) The use of additional optical fiber

Additional optical fiber is used to connect OTDR and optical fiber which under test, 300 ~ 2000 m long fiber, its main role is: the front insert measuring blind area processing and terminal connector.

 

In general, OTDR and optical fiber connectors between blind area under test is the largest. In actual measurement of the optical fiber in the OTDR with fiber and after a period of transition, the front end blind area falls within the transition of optical fiber, the fiber under test head fell on the OTDR curve in the linear region. Optical fiber system between connector insertion loss by OTDR testers and optical fiber to measure for a period of transition. As to measure the first and end connector on both ends of the insertion loss, can add a transitional fiber in every side.

Maintance Methods Of Fusion Splicer Parts

by Fiber-MART.COM

The most common parts of a fiber fusion splicer include Electrodes and V-Grooves. Fusion splicers are dependent upon high-quality electrodes to focus that critical arc of electricity. As the electrodes wear from use, electrodes gradually worn and lead to weaker splices and higher splice losses. Cleaning electrode is part of the essential maintenance of fusion splicer and will not restore the performance of the fusion splicer as electrodes need to be replaced.

 

Always replace fusion splicer electrodes as a pair. For optimal performance, electrodes should also be aligned when they are replaced. This is a tuning process to maximise the performance of your splicer.

 

The Maintance Methods Of Fiber Fusion Splicer Parts:

1. Electrical welding electrode life is generally about 2000, after a long time the electrode will be oxidized, resulting in the discharge current is too large leaving the splice loss value increases. You can remove the electrodes, medical cotton wool dipped in alcohol to gently wipe and then install the fusion splicer, and discharge cleaned once. If repeated washing, the discharge current is still too large, it shall replace the electrode.

 

Replace the electrode first remove the protection of the electrode chamber cover, loosen the screws fixed on the electrode, remove the upper electrode. Then release the top wire fixed to the lower electrode, remove the lower electrode. Installation of new electrode opposite action of the demolition order, require two electrode tip clearance: 2.6 ± 0.2mm, with the optical fiber symmetry. Under normal circumstances electrode is not required to be adjusted. Not touch the tip of the electrode in the replacement process, prevent damage, and should avoid the electrodes to fall inside the machine. After replacing the electrode to carry out calibration of the arc position.

 

Care of the electrode used for a long time, the tip of the electrode will produce sediment discharge poor, then there will be a “hissing” sound, then need to clean the electrode. The recommended the regular welding machine electrodes care that clean the electrode.

 

2. 4 clean V-shaped groove welding machine tune the core direction of the upper and lower driving range each only tens of microns, slightly foreign body will make the fiber image deviation from the normal position, resulting in normal alignment. At this time the need for timely clean the V-groove:

 

a. Off the windshield of the welding machine.

 

b. Open the fiber optic pressure head and the clamping platen.

 

c. Stick with a cotton swab dipped in anhydrous alcohol (or sharpened toothpick) single wipe in a V-Groove Fiber Aligner.

 

Note: Avoid using hard objects to clean the V-groove or V-groove on the force, to avoid bad V-groove or V-groove inaccurate, resulting in the instrument can not properly use.

 

Proper use of Fusion Splicer is to reduce an important guarantee of the optical fiber splice loss and key links. You always should be strictly in accordance with the instructions of the welding machine and operational procedures. And properly set the welding parameters according to the type of fiber (including pre-discharge current, time and the main discharge current, the main discharge time). Do as above, the working life of your fusion splicer certain can be longer.

Selection Guide on PoE Switch

Currently IP cameras are widely used for video surveillance due to the high requirements for security. Typically, the IP cameras are with PoE functions, then PoE switch is needed for the connection. But some users feel confused about the PoE switch and don’t know how to choose a suitable PoE switch. This article is going to introduce you some guides on PoE switch selection.

 

What Is PoE and PoE Switch?

PoE is short for power over Ethernet. With PoE technology, data and power can be transmitted over a single Cat5e cable. A PoE switch is a device that contains multiple Ethernet ports to provide power and network communications to IP cameras. PoE switch is an economical and reliable solution for small business networks to deploy wireless access points and IP surveillance cameras.

 

Fiberstore poe switch

 

Considerations for PoE Switch Selection

Numbers of Ports

The most important is to check whether the numbers of ports on PoE switch are enough to connect all your devices. Fiberstore offers PoE switches including 8 ports, 24 ports, and 48 ports. PoE ports are flexible to connect with Cat5e cable without additional settings. All of our PoE switches have 2 Gigabit uplink SFP ports or 4 SFP+ ports. Uplink ports allow long distance data transmission between switches. With these ports, you can easily expand your networks. (Check news about PoE switch from fiber-mart.COM: Build and Expand Your Network with fiber-mart.COM New Introduced PoE Switches) So if you need to link multiple switches, you need to select switches with enough Gigabit ports.

 

Power Supplies for Powered Device

PoE switch applies two standards: IEEE802.3af and 802.3at. Each one can offer power for IP cameras. Due to the different standards, the output power of PoE switch is also different. IEEE802.3af can provide 15.4watts DC power on each port. As some power dissipates in the cable, only 12.95watts power at most can be supplied to powered devices. This standard is enough to power VoIP phones, wireless access points and some cameras over standard Ethernet cabling. While, IEEE802.3at is updated PoE standard known as PoE+. It can provide up to 25.5watts power available for powered device which is nearly twice as many as that 802.3af supplies. The updated standard can support more devices with high-power functionality such as door controllers, cameras with zoom capacity, or wireless access points supporting 802.11n.

 

Total Power

PoE switch has a total power. As described before, under IEEE802.3af standard, each port on the PoE switch can get 15.4watts power. Thus, the total power of a 24-port switch must reach 370watts so that it can make sure each port get sufficient power. And make sure there is additional power beyond that required for PoE for its switching functions. As to the IEE802.3at standard, each port supports 30watts. Under this condition, the PoE switch with total power of 370watts can only provide power supply to 12 ports.

 

Cable Requirements

The DC power of IEEE 802.3af standard is 15.4watts. It can support 10BASE-T and 100BASE-T. Two of four twisted pairs of Cat3 cable or higher can support the power and data transmission. The PoE+ standard delivers power up to 30watts and supports 1000BASE-T. Cat5e or Cat6 cable is able to support the power transmission. Connecting PoE switch to the router or cameras with Cat5e or Cat6 cable, the maximum transmission length is up to 100 meters.

 

When buying Ethernet cables, find a reliable vendor who provides standard network cable meeting the strict requirement. PoE power supply must use oxygen-free copper material—standard network cable. Non-standard cable utilizes other materials such as copper clad steel, copper clad aluminum, copper coated iron, etc. These cables are not suitable for PoE power supply because of the big resistance.

 

Conclusion

PoE switch is a cost-effective solution to increase the reliability and security of networks by providing centralized backup power to all connected IP surveillance devices. Before purchasing PoE switches, try to know as more details about the switch specifications as possible and also your own needs. To get good quality PoE switches, please come to fiber-mart.COM.

How to Measure the Fiber Optic Network by Using OTDR Testers?

Optical fiber measurement can be divided into three steps: using OTDR testers for parameter setting, data acquisition and analysis. Measuring parameters include artificial Settings.

(1) the wavelength selection (λ):

Because of different wavelengths corresponding to different features (including attenuation, slightly curved, etc.), generally following the test wavelength and wavelength corresponds to the principle of transmission communication system, the system open 1550 wavelengths, the test wavelength of 1550nm.

 

(2) Pulse Width:

The longer the pulse width, the bigger the dynamic measurement range, measurement of distance is longer, but blind area is bigger in OTDR curve waveform; Short pulse injection of low light level, but can reduce the blind area. Usually stand by ns for pulse width cycle.

 

(3) Range:

OTDR testers measurement range is refers to the maximum distance of OTDR data sampling, the choice of this parameter determines the size of the sampling resolution. Best measurement range for 1.5 ~ 2 times the distance between optic fiber network length.

 

(4) Average time:

The backward scattering light signal is very weak, generally USES the statistical average method to improve the signal-to-noise ratio, average, the longer the average time, the higher signal-to-noise ratio.

 

(5) Parameters of optical fiber

Optical fiber parameter setting including the refractive index n and Backscatter coefficient of η. Refractive index parameters related to distance measuring, backscatter coefficient effects the measurement results of reflection and return loss.

After Parameter Settings, OTDR can be sent and received by the optical fiber link light pulse scattering and reflected light, the photodetector outputs sample, get the OTDR curve, the curve is analyzed to understand quality of optical fiber.

 

Experience and skills

(1) Simple discriminant of fiber quality

Under normal circumstances, OTDR test the light curve of the subject (single or several plate cable) slope are consistent, if a certain section of the slope is bigger, indicates the period of decay; If subject to irregular shape curve, the slope is volatile, it is bent or arc, suggests that bulk fiber cables quality degradation seriously, do not conform to the requirements of the communication.

 

(2) The choice of wavelength and the test of Uni and Bi-direction:

1550 wavelengths to test distance is farther, a 1550nm – 1550nm fiber is more sensitive to bending than 1310. In an actual optical cable maintenance, compare both wavelengths to get good test results.

(3) Clean the joint:

Before accessing optical union, must be cleaned carefully, including OTDR output fiber assembly connectors and measured union, or the insertion loss will too big, otherwise don’t reliable, much noise can stop the measurement, it may also damage the OTDR. Avoid using alcohol cleaning or other refractive index matching liquid, because they can dissolve the adhesive within optical fiber connector.

 

(4) The use of additional optical fiber

Additional optical fiber is used to connect OTDR and optical fiber which under test, 300 ~ 2000 m long fiber, its main role is: the front insert measuring blind area processing and terminal connector.

 

In general, OTDR and optical fiber connectors between blind area under test is the largest. In actual measurement of the optical fiber in the OTDR with fiber and after a period of transition, the front end blind area falls within the transition of optical fiber, the fiber under test head fell on the OTDR curve in the linear region. Optical fiber system between connector insertion loss by OTDR testers and optical fiber to measure for a period of transition. As to measure the first and end connector on both ends of the insertion loss, can add a transitional fiber in every side.