PIDS Sensor Installation & Maintenance. 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 1

Transcription

1 PIDS Sensor Installation & Maintenance 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 1

2 The information contained herein contains proprietary information of ST Electronics (Satcom& Sensor Systems) Pte Ltd and may not be copied, used or disclosed in whole or in part to any third party except with written approval of ST Electronics (Satcom& Sensor Systems) or if it has been authorised under a contract. 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 2

3 1 Sensor Allocation Sensor Coverage Customisation Sensor Allocation Chart Site Measurement 7 2 Tools &Equipments Portable Sensing unit (Braggmeter) Preparation before heading to site 10 3 Pre installation measurement Check sensor cable condition Braggmeter control interface Braggmeter control interface Sensor cable deployment Preparation Sensor labelling Cable tying 16 5 Pre tensioning 26 6 Maintenance 29 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 3

4 1. SENSOR ALLOCATION PRINCIPLE CONSIDERATIONS Sensor cables are manufactured according to Sensor Allocation, which means exactly which fence panels each FBG sensor needs to cover. This is decided based on: Probability of detection requirement Fence stiffness (the stiffer it is, the easier to detect fence cut) Fence pole stiffness Fence material (the softer it is, the more difficult it is to detect fence cut) More FBG sensors may be required to be allocated when it is more difficult for that particular area for the FBG sensor to detect an intrusion 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 4

5 1 1Sensor Coverage Each FBG sensor typically covers a few fence panels, as indicated by the arrows shown in the photo below (Figure 1). Figure 1 An FBG sensor is normally sensitive enough to cover any intrusion attempts over three fence panels when it is placed right in the middle of these three fence panels. Detection of unaided climb will occur readily. Detection of aided climb will occur when the intruder climbs upward or when it starts to climb over after reaching the top of the ladder climb. If higher sensitivity is required, one FBG sensor may only cover two or one fence panel, but cost will increase. 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 5

6 1 2Customisation Customisation of sensor cable can be done for special cases, for example: At corner turns (at least one FBG to be placed on fence panel on either side) At gates (one FBG per leaf, additional length to allow different routing) Where upper and lower part of fence panel is disjoint Sensor cables for mounting on concertina wire or barbed wire are also constructed differently 1 3Sensor Allocation Chart The output is a Sensor Allocation Chart for subsequent deployment Figure 2 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 6

7 1 4Site Measurement Each FBG sensor is embedded on a single core optical fibre cable based on the Sensor Allocation Chart and the spacing between two sensors Thus, site measurement is required to determine the spacing between two sensors, taking into account the following: No. of fence panels Varying fence widths Varying fence heights Corner turns Gates Additional length if there is a need to wrap around fence poles 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 7

8 2. TOOLS & EQUIPMENTS 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 8

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10 2 1 Portable Sensing Unit (Braggmeter) Figure 3 VGA Connector CMA Connector LAN Connector USB Connector (2X) Fan Figure 4 11 Power Connector ON/OFF button Optical Channel Connector CH0 Optical Channel Connector CH1 Optical Channel Connector CH2 Optical Channel Connector CH3 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 10

11 2 2Preparation Before Heading To Site Pack all the necessary items: cutter nipple, cable ties, tool pouch, extra connector caps and adaptors, etc. inside the toolbox. Check that you have all the necessary equipment and tools before you head to the site. The sensor allocation chart is required for deployment. Note: All the equipment used and steps involved may vary depending on the working environment and workplace. Consult and verify first before heading to the site. 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 11

12 3. PRE INSTALLATION MEASUREMENT 3 1Check Sensor Cable Condition Check for any broken sensor before you deploy it. To do this, connect the sensor cable to any of the optical channel connector (marked with a square in below figure) on the BraggMeter Optical Channel Connector Figure 5 Typically, there should be readings of 25 sensors for one sensor cable, unless otherwise stated on the sensor allocation chart. A fault-free cable would show a straight line on the 0.3 value across the 25 peaks (figure below). Figure 6 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 12

13 A faulty cable would have peak(s) below the 0.3 value (figure 7). Report faulty cables immediately. Figure Spectrum with irregular peaks, many below threshold Note: Pay attention to the cleanliness of the connector. A dirty connector can compromise the measurement and detectability of the sensors. Use a connector cleaner to frequently clean the connectors. 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 13

14 3 2Braggmeter Control Interface 1 Press the ON/OFF button to start the BraggMeter; the software will be launched. An information box displaying the start-up status and on software version will appear on the LCD touch screen. Press the OSA (Optical Spectrum Analyzer) tab at the top main area of the screen. To begin data acquisition, press the Run/Stop button located on the bottom toolbar (Figure 8) Figure 8 INFORMATION BAR: Displays information on status or instructions. ALARM LED: The sensor status is OK if this LED turns green. If there is a blinking red or yellow light, an alarm has been reported. BATTERY STATUS: There are three different states regarding the power situations Charging, Battery OK or Battery low. VIRTUAL KEYBOARD: This button becomes active if there are some properties to write. EJECT EXTERNAL DEVICES: Safely remove external devices such as USB interfaced device. RUN/STOP: Start or stop data acquisition. EXIT: Exit application. (Note: To shut down the Measurement Unit you need to press the start button at the bottom left corner, and select from the drop box and choose shut down and press OK ) 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 14

15 3 3Braggmeter Control Interface 2 The spectrum of the FBG sensors will be displayed (Figure 9). Figure 9 The normalized power spectral distribution of each individual sensor is displayed. The optical channel dropdown box allows you to select from channels 0 to 3 after the connector has been connected to that particular channel. Shows information on peak wavelength. Sets threshold value for each optical channel. A keyboard will pop up when pressed. This is an important parameter as it must be set so that all FBG spectrum peaks are above the line. The Threshold Reference Line on the OSA graph. A sensor will not be detected if the peak of the wavelength spectrum is below the reference line. Check how many sensors are detected. The Auto Scale button. Zoom out to display the entire optical spectrum range. 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 15

16 4. SENSOR CABLE DEPLOYMENT 4 1Preparation Prepare the sensor cable for the installation. Refer to and follow the sensor allocation chart exactly so that you will not encounter any issues with the installation. Pack all the cable ties and place the cutter nipple into the tool pouch. Strap the tool pouch to your waist area to access the tools conveniently. Pull out the connector with the cap from the cable reel (Figure 10). Figure 10 Identify the fence that requires each particular sensor is to be mounted. Reel the cable out slowly from the cable reel and lay it out in a straight line on the ground near the fence. Do not pull. Reel out until all the sensor cable is on the ground (Figure 11). Figure 11 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 16

17 4 2Sensor Labelling Each sensor must be located as close to the middle of the fence panel as possible. The sensor is not visible, but it is located right after a label. The purpose of the label is to identify the sensor. The photo below shows that sensor no. 23 is located at Cluster #4, Channel 3. Figure Cable Tying Begin the installation by tying the cable to the fence. Insert the cable ties along the way to allow the cable to hang. Insert the cable tie underneath the cable with its end facing the fence upwards. 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 17

18 Figure 13 For every cable tie that needs to be tied, tighten it to about the diameter of the diameter gauge. This is the amount of tightness required for all cable ties. Insert the end toward the hole of the cable tie to tighten it around the loop. You will hear a zip sound if the tie is properly tied with its front facing as shown below. Figure 14 This is the amount of tightness required for all cable ties, leaving a space equivalent to the diameter gauge. Figure 15 A diameter gauge should be able to fit back in the loop nicely. Remove the diameter gauge. The fence no. is identified with a label that is right before the next approaching fence. The label shown below is fence no /03/13/Rev1/PIDS Sensor Installation & Maintenance 18

19 Figure 16 Repeat the steps for cable tying. Then apply them for every fence. Each cable tie shall have an average distance of about 25 cm from each other. It is not necessary to be exact about two cable ties length will suffice. The cable should now rest in a straight line. It should not be tight. Figure 17 When encountering fence pole in between the two fence panels, leave at least four grid lines to tie another cable tie. Figure 18 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 19

20 Bundle any additional length of the cable and tie it to the pole. There should be double ties to the left and right edge of the fence panel where FBG sensor is present. These are the two points used for pretensioning. They are generally three grids away from the nearest fence pole at both ends. CABLE TYING VARIATION WELDED MESH FENCE When the vertical grid is inward-facing on the same side of the sensor cable, double ties are achieved by criss-crossing both cable ties Figure 19 When the vertical grid is on the opposite side of the sensor cable, double ties are achieved by a regular tie method. Figure 20 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 20

21 CABLE TYING VARIATION CHAIN-LINKED FENCE At points used for pre-tensioning, double ties are achieved by crisscrossing both cable ties. Figure 21 All other points are secured using the regular cable tying method. Figure 22 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 21

22 CABLE INSTALLATION AT MAINTENANCE GATE This step requires a ladder to reach and hang the cable above the maintenance gate (see photo). Right above the gate, tie the cable tightly so that it does not hang loose. Such installation is sufficient for detecting any opening / closing of maintenance gate. Figure 23 CABLE INSTALLATION AT SWING GATE Detection of intrusion via swing gate can be achieved by looping the sensor cable on each gate, with one FBG sensors on it. To loop back FO cable on each gate and bury across gate to avoid disjoint FBG Sensor From previous FBG Sensor 1.3m To next FBG Sensor Figure 24 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 22

23 Leave sufficient slack for the gate to open. Figure 25 CABLE INSTALLATION ON BARBED WIRE Cables can be fitted on the barbed wire on top of the fence. It can also be fitted on perimeter with either brick wall or steel cladding with no fence but with barbed wire. Figure 26 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 23

24 Installation is done by laying sensor cable along the barbed wire. Sensor cable is laid diagonally down from the top of one out-rigger to the bottom of the next out-rigger and then laid diagonally up to the out-rigger of the next out-rigger, and so on and so forth. In this manner, the sensor cable will be laid pass each of the barbed wire. Cable ties are then used to secure the sensor cable to the barbed wire where they cross each other. For a typical four-wire barbed wire, each wire is secured with a cable tie. Method of securing the cables remains the same as securing it on a fence. The pre-tension is maintained only on the middle two wires. The tensioned cable is clamped to secure the sensor location each of two adjacent pole posts is connected to one sensor. Figure 27 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 24

25 CABLE INSTALLATION ON CONCERTINA WIRE Method of securing the cable remains the same as that for barbed wire. The tying points are on the middle point (in terms of height) of the concertina wire, at the side inside the premises under protection. Figure 28 Pre-tension is maintained by clamping left and right edge of the fence panel where FBG sensor is present. Figure 29 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 25

26 FINISHING TOUCH At the last fence panel of a sensor channel, for both ends before approaching the connector, leave the remaining part of the cable in a vertical position. Tie it to the grid. Leave about two cable ties spacing before the next tie. Hang the remaining cable loosely. Leave it dangling with the cap on at all times. The cable end should be roughly 15cm of the ground. Figure 31 Leave the cable end above the ground. Figure 30 After cable tying is completed, use the cutter nipple to cut the dangling part of all the cable ties, except the double ties used to secure the cables with sensors. 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 26

27 After all the procedures above have been completed, double-check the sensor allocation chart and re-adjust the positions accordingly This is important as the next section requires all the sensors to be in the correct position in order for the pre-tension to proceed successfully. 5. PRE TENSIONING PRE-REQUISITES Every sensor needs to be pre-tensioned to be more sensitive Pre-tensioning requires a portable Sensing Unit to measure the sensor wavelengths. Pre-tensioning requires two skilled personnel for the job, one to apply pretension to the sensor, while the other to monitor the wavelength spectrum and its distribution (via the portable Sensing Unit). CABLE TIGHTENING / LOOSENING The higher the pre-tension is, the higher the wavelength will become. By tightening or loosening the cable, adjust the wavelength as displayed in the portable Sensing Unit to either a higher or a lower level. Adjust the cable element until the particular sensor reaches a desirable wavelength. Once reached, tie the cable tightly with cable tie. Figure 32 Always be ready to communicate with your partner as the wavelength will change frequently. A common error is that the wrong sensor is being adjusted. So, clarify when in doubt. 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 27

28 Head back to re-adjust the cable for the neighbouring sensors previously done whenever necessary. WAVELENGTH MONITORING Prepare the patch cord to connect the portable Sensing Unit over a much longer distance if necessary. Lay the patch cord as straight as possible on the ground to prevent the cable from being twisted and pull the patch cord lightly; otherwise, it may break the connection to the sensors. Step 1 Wavelength Spectrum Adjustment Get a wavelength log ready to adjust all values of each sensor to an increase of 1.25nm from its initial value. All wavelengths should be increased by 0.75 to 1.25nm from the initial value, which by default ranges from ~1512nm to ~1584nm (all 25 sensors). Make sure you are at the OSA tab. Run the data acquisition after the Portable Sensing Unit is connected to the connector. If the peak of the wavelength spectrum is below the threshold reference line, report the cable as faulty. Figure 33 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 28

29 Step 2 Tuning Techniques The key to tuning the sensors wavelength is to be responsive to wavelength changes. Wait for the wavelength to settle down and tell your partner to check whether the wavelength is at an acceptable value, too high or too low. The major concern is the overlapping of two neighbouring ranges. The wavelength that is too high due to tension could break the sensor. That is why it is important to always inspect the wavelength spectrum, especially for the adjustment of that particular sensor and its neighbour (left and right). Step 3 Recording Record the wavelength and its changes into the wavelength log. The identification number, type of channel and its sensor cable serial number will be shown. This record will display from sensor 1 to 25 by default. Add remarks whenever necessary so that you can deal with any issues that may occur after the installation is complete. 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 29

30 6. MAINTENANCE MAINTENANCE REQUIREMENT The main maintenance requirement for the sensors is its pre-tension level. This is aided by real time monitoring; there is thus no need for user to go to the perimeter site to stimulate a fence disturbance to check if the sensors are intact or not. Visual inspection is carried out during scheduled maintenance to look for any broken cable ties (sampling check of cable tie condition). MONITORING OF PRE-TENSION The pre-tension level of the sensor cable can remain over a long period of time A white box means the sensor s pre-tension level is good and it is intact. Figure 34 However, the pre-tension level may drop slowly over time for some sensors where there were heavy activities which caused frequent fence disturbances 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 30

31 This is checked during 3-monthly scheduled maintenance Within a certain tolerance level, the sensor s sensitivity is still considered acceptable but pre-tensioning needs to be carried out during scheduled maintenance. Beyond this acceptable tolerance level, the sensor s sensitivity is no longer considered acceptable and pre-tensioning needs to be carried out immediately. Sensors which have lost some pre-tension and need to be pre-tensioned again is marked in yellow 1 If 5% yellow, pre-tensioning to be done in next 3-monthly maintenance. If < 5% yellow, pre-tensioning can be postponed. 1 Figure 35 However, the pre-tension level may drop slowly over time for some sensors where there were heavy activities which caused frequent fence disturbances This is checked during 3-monthly scheduled maintenance Within a certain tolerance level, the sensor s sensitivity is still considered acceptable but pre-tensioning needs to be carried out during scheduled maintenance. Beyond this acceptable tolerance level, the sensor s sensitivity is no longer considered acceptable and pre-tensioning needs to be carried out immediately. 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 31

32 Sensors which have lost its pre-tension significantly to warrant an immediate recovery of pre-tension level is marked in blue. 2 2 Figure 36 Note that a string of blue boxes indicate a sensor break (can be caused by cable cut) rather than a pre-tension drop, and warrants an immediate corrective maintenance to repair the break. 3 3 Figure 37 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 32

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34 ST Electronics ( Satcom & Sensor Systems ) Pte Ltd 1 Ang Mo Kio Electronics Park Road, #06 02, ST Engineering Hub, Singapore T: (65) F: Regn.: W 15/03/13/Rev1/PIDS Sensor Installation & Maintenance 34