User`s manual Shielding Effectiveness Measurement
Contents
1. 0 0 01 0000 To 4 000000 Save By clicking on the desired element and then pressing Retrieve data will be downloaded from the SEMS internal memory and shown on the main window you will be asked to save an optional record file for latter reference _ 44 USER S MANUAL SEMS To retrieve a single measure access the option from the relative menu Tools gt Retrieve gt Single Measure and select the desired measure from the popup window Pw 1 15 04 06 10 Organize v New folder 1 Downloads Name Date modified Type 10 0 010000 To 4 000000 35 Recent Places a Chamber A 25 02 2011 11 52 File foldelli Uninstall 25 02 2011 10 02 File folde Dnem lt N ieee Au _ default SMR 14 12 2009 06 56 SMR File a Music E Pictures BJ Videos Documents ji Computer Os ESEN Save Clicking retrieve will update data currently shown on the screen with the retrieved measure and allows you to save the measure as a record file SMR To correlate the memory slot to the index of the measure you can refer to the following table Memory Slot To consult this measure again just use the Load button from the File menu and select the relative record file _ 45 USER S MANUAL SEMS Retrieving a set of measures works in a similar fashion To retrieve all data relative to a chamber you have to click on Retrieve gt Set of Measure from the Tools menu then select the dataset from t2. 2 2 SEMS Transmitter The block diagram below b represents the SEMS transmitter Digital Power RF CPU gt Doubler gt Di T The transmitting signal is generated using the DDS controlled by the CPU that receives the instructions from the receiver wireless interface this signal is duplicated and amplified in order to achieve the necessary level to be transmitted by the transmitting antenna Figure b 10 USER S MANUAL SEMS 2 3 SEMS System The main purpose of the SEMS is to measure the shielding effectiveness in a shielded environment by measuring the attenuation of the electric or magnetic field We can briefly describe the operating principle as it follows The transmitter generates a RF signal and irradiates it through the antenna at a certain distance the receiver catches the signal with an equal antenna and measures the signal level If we move the receiver inside the shielded environment maintaining the same distance from the transmitter we will get a lower signal so we can consider the shielding attenuation the difference between the reduced and the Original signal D ZERO SETTING Distance for E the zeroing process Picture n 06 Example of zeroing with loop antennas 2 4 Power saving and recalibration The SEMS has an integrated timer in both RX and TX unit for two different reasons the TX automatically turns off after 17 min of idle to save the battery the RX unit after 15 min
3. 10 KHz 30MHz 1 0dB 30 MHz 300MHz 1 5dB The following image show the procedure set up Picture n 07 _29 USER S MANUAL SEMS 3 7 Howto use the active bridge The active bridge has been developed to improve the connection between Tx and Rx this is very useful when the shielding that is tested is too high to ensure the direct wireless connection between the devices 2 4GHz using the wireless optical cable adapter you can solve the problem allowing the regular performance of the test The active bridge consists in two wireless optical fiber adapter modules called wireless bridge master and wireless bridge slave the modules are connected b through the optical cable and powered by AAA batteries To set up the active bridge you have to turn on the wireless bridge master device and the module linked to the RS232 wireless adapter called slave and wait for their connection The next step is to turn on the wireless bridge slave device and the other module and wait for their connection In both cases the successful connection will be confirmed by the green light of the led steady on both modules As soon as the connection is established it s possible to check the battery status of the Tx on the Rx display The optical fiber which connects the master and the slave devices should pass under the door in a fingerless zone if the finger does not allow the fiber placement the proper channel located
4. MANUAL SEMS After the first measurement you ll see that before each frequency there is a synchronization delay 10 000000 MHz Sync in 2s Att 88 0 dB Abort As soon as the measurement ends you ll see the usual Spot Done screen from Wizard mode where you can repeat the measurement ReDo or start measuring the next if there is one spot Next In both Standard and Wizard mode you have a limited time to make the measurements before reconnecting the RX and TX unit This time limit is used to avoid measurement errors imputable to long term clock delays The timer starts from the moment in which you press the Unc button After 14 minutes if you start a measurement you will be prompted to reconnect the TX and RX unit to recalibrate the internal clocks Re Sync Needed Connect RX TX then press OK Abort At this point you must reconnect the RS232 Wireless adapter wait for the steady green light to appear and then press OK Boe USER S MANUAL SEMS If the connection is successful you ll see the following screen Sync OK Remove Connections Abort Now you are able to start the measurement the 14 minutes timer is restarted If the connection fails keep in mind that after 17 minutes the TX Unit turns off automatically you will see the following screen Synchronizing Transmitter And after pressing OK Could not Sync Failed Is TX connected Abort In this case check the TX c
5. from the last zero setting suggests to recalibrate the SEMS by repeating the procedure 11 USER S MANUAL SEMS 3 System use and operations 3 1 Turn on menu By pressing the power button of the RX module the device will turn on to turn it off press the power button for at least 4 seconds Follow the same procedure for the TX module As soon as the device is turned on the display will show the following screenshot On the top right of the screen will appear a battery icon to show the charge status of the RX module then the TX connection on the top left will appear the TX device battery icon SEMS FW 1 XX XX XX XX HW 2 NOTE As soon as the connection is established if the red led of the wireless devices blinks together with the yellow ones wait until the complete switching off of the first ones in order to let the devices synchronize and ensure the correct functioning 3 2 Std Menu By pressing the Std menu button this screenshot will appear SEMS a FW 1 XX XX XX XX Show Cal Then pressing the relative button allows the access to Show and Cal menu _12 USER S MANUAL SEMS 3 2 1 Cal Menu Cal menu is used to perform the system zeroing process Scan or List or the system calibration process Calk i SEMS a Ready for Measuring Scan List Calk Scan performs the system zeroing process using the standard or customized frequency bands by pressing the scan button we will see the f
6. the Meas button in Std appears only after a zero has been done and the Unc mode is available only if the zero has been done with a list made of less than 20 frequencies _4 USER S MANUAL SEMS 4 SEMS PC Utility software controls and functions 4 1 Installation Insert the USB Drive that came along with your SEMS system into the PC you are installing the software to SEMS SW exe N Setup Application UP 9 010 Launch the setup file SEMS SW exe and click YES in the pop up window Vista and Seven users only According to your computer settings SEMS SW Installer will have on screen instruction in different language 22 SEMS Software Installazione Benvenuto Benvenuto al programma di installazione di SEMS Software 1 22 E vivamente consigliato uscire da tutti i programmi Windows prima di continuare con questa installazione Se ci sono altri programmi in esecuzione prego premere Annulla e chiudere questi programmi prima di rilanciare l installazione Altrimenti premere Avanti per continuare Follow the instructions on screen to complete the installation A USER S MANUAL SEMS 4 2 Connecting the instrument Plug the USB to Serial adapter to your computer Under Windows Seven press Start go in Control Panel then Hardware and sound then Device Manager 3 Under Windows XP press Start go in Control Panel then System then Hardware then Device Manager 4 Tak
7. Software with a specific list of no more than 20 frequencies The list can be saved in any of the three L1 3 slots The Unconnected mode can be used either in the Wizard or in the Standard mode To use it in Standard mode select Std from the home menu SEMS a FW 1 20 09 07 11 HW 2 Press Cal then List and then select the list where you saved the frequencies for the unconnected mode Proceed with the zeroing sequence as you would do for a normal measurement 90 USER S MANUAL SEMS As soon as the zeroing sequence ends press Meas a SEMS j Ready for Measuring Auto Man PreQ Unc Place the TX and RX units in the desired measurement spot and press the Unc button to enable the two units to synchronize their internal clock Note that you have to make this step while the 2 batteries are visible on the LCD display Remove Connections and start measuring Now 10s 30s Now you can remove the RS232 Wireless adapter from the RX unit you ll see the battery icon of the TX Unit that disappears close the door of the shielded environment and start measuring oe USER S MANUAL SEMS You ll see a countdown starting from a value that can vary according to the moment in which you started the measurement and the number of frequencies you entered in the list 5 000000 MHz Sync in 12 s After the first measurement you ll see that before each frequency there is a synchronization delay 10 000000 MHz S
8. X units only if you need to change the working frequency 20 USER S MANUAL SEMS 3 3 WIZ menu To improve the management of the measurement saving procedure you can use the SEMS s wizard for a better organization of data storage To use the wizard press the WIZ button in the top menu of the device The wizard will lead the user throughout the procedure asking the following questions The selection of the chamber where the measurements are performed A B C D Using A B C e D you can identify a shielded chamber Then the user has to remember the letter assigned to the chamber where the measurements were done a Choose the i Chamber you want To measure Choice of the maximum number of spot to be measured 1 2 4 8 Represents the number of measuring spot assigned for each chamber The user must sort chronologically the measured spot and he will find the same order in the instrument memory Selectthemax number of spot to be measured USER S MANUAL SEMS The selection of ranges antennas to be measured 1 2 3 4 it represents the number of antennas systems available to the user during the measurements When you perform the measurements at all the points specified previously the system will switch range asking you to replace the antennas and redo the auto zero procedure fi Select the number B of ranges antennas to be measured 3 3 1 Measurement using wizard Afte
9. ally Man i Fully Zeroed Di Ready for Measuring Auto Man PreQ Unc Using the automatic mode you can choose if you want the measurement procedure to start immediately Now or with a fixed time delay 10s 30s e 60s SEMS E Ready for Measuring 17 USER S MANUAL SEMS If you use a manual measurement you will use the commands Prev measure of the previous frequency Next measure of the next frequency Redo in order to measure the current frequency and Abort to end the measurement To measure the electrical component we recommend to use Rod Antennas Mod R 1 completely closed on the RX unit and completely open on the TX unit For the magnetic field you can use the pairs of Loop Antennas L 1 or L 2 60 000000 MHz Rbw 40 Hz Att 56 dB Prev Next Redo Abort When the measurement is finished the display will show the memory slot to store the acquired data you can choose one of the 4 memories for each frequency range Frequency Range from 0 01 to2 MHz memory L 1 L 2 L 3 e L 4 Frequency Range from 2 to 60 MHz memory M 1 M 2 M 3 e M 4 Frequency Range from 60 to 300 MHz memory H 1 H 2 H 3 e H 4 Example Save request in the memory slots from 60 300 MHz range Scan Terminated Press 1 4 to save or Escape By pressing the H 1 button the data will be stored and you will go back to the starting screenshot _18 USER S MANUAL MPB SEMS 3 2 4 Snif Menu From this men
10. and previously stored To see the saved measurements press the Show button H SEMS a Ready for Measuring Meas Show Cal Snif e g We will choose a measure stored in a memory named H1 4 7 SEMS a Ready for Measuring Last L1 4 M1 4 H1 4 _15 USER S MANUAL SEMS Then we recall the H1 memory SEMS Ready for Measuring 1stF Shows the attenuation at the lower frequency of the selected scan or list NxFr Shows the attenuation on the next frequency HiPk Shows the minimum attenuation on the whole scan or list NxPk Shows the first relative minimum of attenuation from the current frequency N Scan j 60 000 to 300 000 iste NxFr HiPk NxPk By pressing the Last button you will see the results of the last measurement performed by pressing the remaining three buttons you can see the other stored data up to 4 for each button As soon as you choose the measure to see you can analyze frequency by frequency the measured attenuation The frequencies are always expressed in MHZ By pressing the ESC button you can go back to the previous menu _ 16 USER S MANUAL SEMS 3 2 3 Meas menu You can find the Meas command in the Std menu but it will appear only when the System is zeroed using the Cal command described in the previous paragraph 3 1 1 of this manual a SEMS j Ready for Measuring Meas Show Cal Snif The command will perform a measurement of attenuation automatically Auto or manu
11. and will appear the wizard management screenshot to control the status of the procedure Bm Ch ASp 1 2R 12 KR spot Done 115 7 dB Next Redo In this screenshot Ch A means that the chosen chamber is called A Sp 1 2 is the measurement spot index in this case the spot is the 1st of the 2 R 1 2 is the antennas system range that we are using in this case we are using the first system of the 2 Spot Done means that the measurement is completed for this spot with the indicated range the value shown nearby beneath brackets is the maximum attenuation of the whole frequencies 24 USER S MANUAL SEMS The Next button must be pressed to get to the next spot If all the required spot have been measured the procedure automatically switches to the next pair of antennas and shows again the auto zeroing screenshot If you used all the antennas systems that you selected the procedure is over and it will return to the main screenshot with a success message about the data storing The Redo button repeats the measurement for the selected spot shown in the screen as soon as this operation is completed the display shows the same screenshot with the updated value of the maximum attenuation The End button stops the measurements with the current set of antennas By pressing it the instrument will ask us to change the antennas and to start the auto zero procedure if the antennas systems have all been sele
12. cted the procedure will end with a message of success about the storing of the data and you will go back to the main screenshot WARNING Pressing the End button in the first antennas system will reduce the spots for all the other systems e g if select 8 spots and measure just 3 pressing end will reduce to 3 the maximum number of spot per system But if we perform a measurement on all of the 8 spots then we will change antennas and then again we will press the end button after just 3 spots measured and all the 5 spots will be kept _25 USER S MANUAL SEMS 3 4 STP Menu SEMS has an internal buzzer that beeps every time that a customizable alarm threshold is exceeded To activate this function you have to press the Stp button in the main screenshot shown as you turn the instrument off BEEP OFF 20dB Use arrows for 10 dB step ON OFF Using the up and down arrows on the SEMS keyboard is possible to move the threshold to 10 dB to set a more fine value is possible to press the 1 and 1 buttons to increase or decrease the threshold to 1 dB By pressing the ON button the buzzer will be activated and during the measurements if the attenuation measured drops below the threshold the buzzer will produce an acoustic signal While the measured value remains under the threshold the buzzer will produce a fast series of beeps when the measured value returns over the threshold the buzzer will be still beeping b
13. e Tx Supposing you are updating the Rx unit the following screen will appear Make sure SEMS RX is OFF Then Turn it ON Abort Turn off the receiver and then turn it on again _ 49 USER S MANUAL SEMS It will show the upgrade window Form1 Db Bems_RX BIN FPGA SemsFw ldr Firmware Update Firmware The updatable file SemsFw ldr should be located in the SEMS software directory Press the Update Firmware button and wait for the loading When the upgrade is completed close the window and turn off the receiver Other information www gruppompb com Technical information assistenza gruppompb com Phone 39 06 41200744 S
14. e note of the COM port where the USB to Serial interface is mapped I E COMS3 eo 5 4g IDE ATA ATAPI controllers gt 4 Imaging devices gt Keyboards gt PA Mice and other pointing devices gt BO Monitors A F Processors b Sound video and game controllers JE System devices Mi Universal Serial Bus controllers 5 Connect the SEMS RX to the RS232 connector and turn on the unit 6 Start the SEMS SW from the desktop shortcut or your start menu 7 Open the Option menu click on Select Comm and in the new window insert the number you ve taken note before Press the Enter key on your keyboard to confirm The program should be now correctly configured to communicate with the SEMS RX unit Note Please use the driver version that comes with the SEMS for the USB to Serial interface _ 43 USER S MANUAL SEMS 4 3 Retrieving a measurement Through the Tools menu you can access different functions to query the RX unit Li SEMS DefauitsMR_ TI File Option Tools Retrieve Single Measure Sorted By Update Firmware b Set Of Measure Get Calk Report Measure e Single Measure will download a single measurement previously stored in the SEMS memory e Set of Measure will download data relative to a specific room data set e Get CalK Report will download data relative to the calibration procedure a TXT file with the report will be created Fw 1 15 04 06 10
15. easurement accuracy 10 kHz 30 MHz 1 0dB typical 30 MHz 300 MHz 1 5 dB I O interface RS232 Wireless Buzzer Ss Tosetonattenuationleve International standard compliance MIL Std 285 IEEE Std 299 EN 50147 1 NSA65 6 Operating temperature 0 40 C Battery Irreplaceable and rechargeable Li lon 6 h operating time Antennas Loop Mod L1 Frequency range 2 128 MHz Diameter 30 cm Biconical Mod B1 Frequency range 60 300 MHz Width 35 cm Calibration Set Up and Measurement Programmable with the software Options Loop Antennas Mod L2 Frequency range 10kHz 4 MHz Diameter 30 cm Rod Antennas Mod R1 Frequency range 1 MHz 60 MHz Wooden tripod Mod TR 02 A Height settable Optic link 30 m Weight and dimensions Overall weight 9 4 kg Case dimensions 52x43x23cm Technical specifications may change without notice USER S MANUAL SEMS 2 Operating principle 2 1 SEMS Receiver The block diagram a below represents the SEMS receiver Digital i Attenuator gt Filters gt ADC gt Display RSP DSP Figure a First of all the RF signal received by the antenna is attenuated by the attenuator module to fit the level to the next modules specifications subsequently we can find the filters to select the bandwidth depending on the frequency settings Then the RF Signal is converted by an ADC and is processed by the digital part with a RSP anda DSP the result will be shown on the display
16. he pop up window amp Retrieve ae Fw 1 15 04 06 10 Retrieving Chamber B Range 1 Spot 1 Chamber 4 Range 1 Measures 1 Chamber B Range 1 Measures Chamber D Range 1 Measures 3 In this example we are retrieving data from Chamber B Range 1 As you can see the window is showing the number of measures relative to each set in this case 4 different spots _ 46 USER S MANUAL SEMS As the download finishes you are not prompted to save your data this is because SEMS automatically saves sets of measures inside its own work folder To consult all data inherent to the chamber just click File gt Load amp Chamber A a Chamber B d Uninstall default SMR amp Videos MS Computer amp Local Disk C al Apple iPhone Filename PONAT Inside Chamber B folder you will find organized in subfolders relative to the antenna Range used all the measurement spots By selecting one of the SMR files the main window updates data with the one relative to the spot selected In addition a new window appears to allow easy navigation between the measurement spots Spot_2 SMR 1 Spot_3 SMR Spot_4 SMR a CA 2 Program Files EQ SEMS Software 4 Chamber B In the lower part of this window you can navigate through the work folder and select the desired chamber range in the top part of the window the measurement spots contained in the relative folder are shown Yo
17. ollowing screenshot where is possible to choose the default bands L_Lo L_Hi e Bic or the user s customized bands pressing the User button customized bands are programmed with the SEMS PC_ Utility software 7 SEMS a Ready for Measuring L Lo LH Bic User The choice of the button to press depends on the different types of antennas L Lo Loop antennas Mod L2 L Hi Loop antennas Mod L1 Bic Biconical antennas Mod B1 By pressing the User button will appear the screenshot to choose the memorized band 313 USER S MANUAL SEMS a SEMS a Ready for Measuring Sci Sc2 Sco Sc4 List performs the system zeroing process using the default or programmable frequency list by pressing the list button will appear a new menu where you can select the default frequency list DFT or three programmable lists L1 L2 e L3 SEMS H Ready for Measuring CalK performs the system calibration process using the four 30 dB attenuators supplied in the CAL KIT NOTE This procedure needs a wireless connection between TX and RX you can control the connection with the battery status on the left top of the screen of RX will be visible only if the connection has been successful _14 USER S MANUAL SEMS When the zeroing procedure ends the following menu will appear a Fully Zeroed E Ready for Measuring Meas Show Cal Snif 3 2 2 Show menu The show menu will provide the results of the measurements performed
18. onnection and if needed turn on the unit Then try again by pressing OK SP USER S MANUAL SEMS 3 10 Prequiet Mode Some shielded environments are naturally noisy The background noise of the environment can affect the quality of the measurement itself To avoid this the SEMS has a cleaning function called Prequiet Mode In the Prequiet Mode the SEMS RX modifies the working frequencies so that the environmental noise is kept out of the measurement points The Prequiet mode is available in both Wizard and Standard mode but it can t be used together with Unconnected mode In both cases you have to do the zeroing of the system then in the Meas menu you ll find the PreQ button In Standard mode i SEMS a Ready for Measuring Auto Man PreQ Unc And in Wizard mode Fully Zeroed Ready for Measuring Auto Man PreQ Unc _ 39 USER S MANUAL SEMS As soon as the quieting procedure finishes you can start the measurement Quieting Terminated Meas Show Cal Snif By pressing Meas and starting a measure the SEMS will automatically use the optimized frequency list _ 40 USER S MANUAL SEMS 3 11 SEMS Menu Map The following image shows a map of the SEMS Menu For fitting reasons the Wizard menu stops where the actual measurement starts but it s basically equivalent to the Std menu from that point on Dotted connections shows a button that appears only under some circumstances
19. or _ Ee Alphanumeric display m LO ef Keyboard Power button Picture n 03 1 6 Transmitter front panel The SEMS transmitter Picture n 04 has no command button but a power button since the commands are sent by the receiver using the wireless connection TTTTTTT RF out 50 Ohm N female connector Power button NI nes oat jeldi en men n tive gure m Picture n 04 USER S MANUAL SEMS 1 7 Receiver Transmitter rear panel The rear panels Picture n 05 are the same for both devices and upon them is possible to find the serial number the thread used for the tripod the battery charger connector and the RS232 interface for the wireless link n gt II D Picture n 905 RS232 Serial number Thread insert 1 4 Battery charger connector Important note Always use the battery charger provided with the instrument to avoid serious damages to the devices and operator s injuries Important note The battery charger must be connected to both devices Tx and Rx turned off USER S MANUAL SEMS 1 8 Technical specifications Frequency range for TX RX 10 kHz 300 MHz Resolution 10 Hz RF out TX module Zout D0 Q N fem Max output power typical 30 dBm RF in RX module Zin 00 Q N fem VSWR lt 1 2 Attenuator 0 20dB Max input power 110 dBuV Dynamic Range 120 dB IF bandwidth RX module 3 dB bandwidth 5 150Hz Attenuation m
20. quency range the other one is used to measure the electric field attenuation in the 60 to 300MHz frequency range Contrary to today s available systems that measure the shielding effectiveness on few frequency points SEMS allows to perform a complete test on the whole frequency ranges continuously Another improvement compared to the standard system is the synchronization component TX and RX are connected by a wireless system that allows to perform automatically the measurement minimizing the user s errors Picture n 01 SEMS in the transport bag USER S MANUAL SEMS 1 3 Standard accessories 1 SEMS recelver 2 SEMS transmitter 3 2 biconical antennas 60 300 MHz 4 2 loop antennas 2 128 MHz 5 2 RS232 wireless 6 2 Battery chargers 7 2 4GHz Active bridge 8 2 adapters for the antennas 9 RS232 cable and RS232 USB adapter 10 User s Manual and software SEMS PC utility in a USB key 11 Carrying bag Picture n 02 1 4 Optional accessories 2 Loop antennas Mod L2 10 kHz 4 MHz frequency range 2 Rod antennas Mod R1 1MHz 60 MHz frequency range plus 10 dB attenuator read chapter 3 7 2 Wooden tripod Mod TR 02 A f I r Loop Mod L2 Rod Mod R1 Tripod Mod TR 02 A USER S MANUAL SEMS 1 5 Receiver front panel In the Picture below n 03 is represented SEMS receiver front panel It has a display and a command keyboard RF in 50 Ohm N female connect
21. r the selection of the chamber spots and ranges the instrument will start the procedure to perform the auto zero required by the first set of antennas to be used The procedure to follow for this purpose is exactly the same of the auto zero calibration as described in chapter 3 1 1 of this manual Choose the range for Antenna 1 Zero Scan List Selecting Scan we can choose to zeroing the system using the default mode L_Lo L_Hi BIC or to use the span programmable by the SEMS PC_ Utility software mode User D USER S MANUAL SEMS Choose the range a for Antenna 1 Zero Llo LHI Bic As soon as the zeroing procedure is completed the measurement screenshot will appear on the display In this screenshot the user has to decide how to perform the measurements automatically Auto or manually Man i Fully Zeroed j Ready for Measuring Auto Man PreQ Choosing the automatic mode we can make it start immediately Now or set a fixed time countdown before starting 10s 30s e 60s FulyZered Ready for Measuring sO USER S MANUAL SEMS When the manual mode is selected the user has to choose the commands Prev to measure the previous frequency Next for the next frequency Redo to repeat the measurement on the current frequency or Abort to quit 60 000000 MHz Rbw 40 Hz Att 65 dB Prev Next Redo Abort After this choice the measurement will be performed
22. stem As the measure ends save the result in a memory Repeat the 5 6 and 7 steps for each measurement spot After all the spots are measured download the results on a PC using SEMS PC Utility software provided with the product 297 USER S MANUAL SEMS 3 6 Calibration using Calkit The SEMS needs a periodic linear calibration the Cal Kit can easily and precisely accomplish this purpose If required the Cal Kit can be provided with SIT calibration To start the calibration procedure press Std Cal button from the main menu and press CalK button then calibration can be performed following the instructions on the display This screenshot shows the request for the 30 dB attenuator Insert 30 dB Attenuator HW 2 Abort Connect the Tx and Rx using the 30 dB attenuator and press the OK button This screenshot shows the request for the second attenuator Insert 2 X 30 dB 60 dB Attenuator Abort Connect the second attenuator and then press the OK button Repeat the same operation until you will use all the four 30 dB attenuators 4x30 dB 120 dB _ 28 USER S MANUAL SEMS When the calibration is done the following screenshot will be shown Calibration done Worst 0 70 dB 20 000 kHz 120 dB Show Cal The Worst parameter shows the worst accuracy over frequencies in this case is 0 7 dB at 20 000kHZz typically is a parameter that you can find in the technical specifications of the chamber
23. tion Standard accessories Optional accessories Recelver front panel Transmitter front panel Receiver transmitter rear panel Technical specifications 2 1 SEMS receiver 2 2 SEMS transmitter 2 3 SEMS system 2 4 Power saving and recalibration 3 Systemuseandoperation 3 1 Turn on menu 3 2 Std Menu 3 2 1 Cal Menu 3 2 2 Show Menu o L ee ee ee eS o NOOA WN O 3 2 3 Meas Menu 3 2 4 Sniff Menu 3 3 WIZ Menu 3 3 1 Measurements using wizard 3 4 STP Menu 3 5 Measuring the shielding attenuation 3 6 Calibration using CalKit 3 7 How to use the active bridge 3 8 Measurement with Rod antennas mod R1 3 9 Unconnected mode 3 10 Prequiet mode 3 11 SEMS Menu Map 4 1 Installation 4 2 Connecting the istrument 4 3 Retrieving a measurement 4 4 Working with the results 4 5 Firmware upgrade USER S MANUAL SEMS 1 General information 1 1 Introduction SEMS is thought to comply the raising need to test and verify the shielding effectiveness of shielded environment in hospitals and industries This system allows to measure automatically with high speed and accuracy the attenuation value of the magnetic and electric field in shielded environments 1 2 System description The shielding effectiveness measurement system has a transmitter and a receiver both of them are provided with a pair of very small antennas one is used to measure the magnetic field attenuation in the 2MHz to 128MHz fre
24. ty 4 M PB MPB S r l Tel 39 0641200744 Via Giacomo Peroni 400 402 Fax 39 0641200653 00131 Rome Italy info gruppompb com User s manual SEMS Shielding Effectiveness Measurement System MPB 2010 ver 2_6 USER S MANUAL SEMS SAFETY NOTE Read before using the product MPB works to provide to its customers the best safety conditions available complying with the current safety standards The instrumentation described in this manual has been produced tested and left the factory in conditions that fully comply the European standards To maintain it in safe conditions and ensure the correct use these general instructions must be fully understood and applied before using the product This product is designed for industrial environment and laboratories and should be used by skilled staff only MPB disclaims responsibility for a different use of the device USER S MANUAL SEMS Conformity Certificate in accordance with the Directives EMC 89 336 EEC and Low Voltage 73 23 EEC This is to certify that the product SEMS Measurement system of shielding effectiveness complies with the following European Standards Safety CEI EN 61010 1 2001 EMC EN 61326 1 2007 This product complies with the requirements of the Low Voltage Directive 2006 95 CE and with the EMC Directive 2004 108 CE MPB S r l USER S MANUAL SEMS Index 7 General information Page Introduction System descrip
25. typically near the filter s panel should be used IMPORTANT NOTE As soon as the connection is established if the red led of the wireless devices blink together with the yellow ones wait until the complete switching off of the first ones in order to let the devices synchronize and ensure the correct functioning On the active bridge devices there is no red led just wait for the complete switching off of the red led on the TX RX to ensure the proper functioning _ 30 USER S MANUAL SEMS 3 8 Measurement with Rod antennas mod R1 When using Rod antennas in the zero setting and in the measurement phase it s absolutely necessary to connect the SEMS TX 10 dB attenuator already supplied before connecting the Rod antenna image n 08 WARNING not using the attenuator can cause serious troubles to the system functionality Picture n 08 A USER S MANUAL SEMS 3 9 Unconnected Mode Some measurement applications are not suited for the usage of the RS232 Wireless adapter or the Optical Wireless Bridge An example could be a measurement in a shielded environment with no waveguides on technical panels and a finger line in the lower part of the door For those kind of applications there s a specific operating mode called Unconnected In this operating mode during the measurement there s no need of a connection between the RX and TX unit To use this operating mode the SEMS RX must be programmed through the SEMS
26. u can select one of these spot and update the data shown on the main window by single clicking it _47 USER S MANUAL SEMS 4 4 Working with the results e Thecolorofthe graphic can be changed from Options gt Graphic Color e The axis reference can be modified by double clicking the maximum and minimum value of the axis and inserting the desired value oI 100 MH 300 MH e You can change the diagram data from Attenuation to Shielding Effectiveness from Options gt Diagram Style e Using the File menu you can save or load a record file or export data in CSV ASCII format 48 USER S MANUAL SEMS e By clicking any point in the graph you can place a marker showing the attenuation of the closest measurement point if the box is Yellow the measurement point is below the instrument dynamic range 98 78 dB 144 885 kHz 4 5 Firmware upgrade Both the transmitter and the receiver firmware can be updated in the same way Be sure that the firmware files are located in the SEMS Software folder Recharge the unit batteries and connect it to the PC using RS232 cable Turn on the unit run the SEMS Software and set the COM port in the Option menu pressing Select Comm To verify the assignation of the COM port assigned by the PC check in the control panel System Hardware peripheral ports To start the firmware update procedure click the Tools button Update Firmware and then Update Rx or Updat
27. u you can measure the shielding effectiveness on a single frequency for leak sniffing purposes 137 520975 MHz RBW 40Hz to 137 520975 Next Prev Press Next or Prev to select the desired working frequency for the sniffer 144 210005 MHz TX Tuned and Ready to 144 210005 Next Prev Meas By pressing Meas the SEMS will start measuring the shielding effectiveness on the selected frequency displaying the current attenuation along with the maximum and minimum value in brackets 144 210005 MHz 112 4 134 4 Att 120 1 dB 19 USER S MANUAL SEMS By pressing Clear the maximum and minimum values are reset and by pressing Stop you will halt the measure 144 210005 MHz Sniffing terminated 112 4 134 4 Meas Show Cal Snif By pressing Snif again you can restart the sniffing sequence or select a different frequency Keep in mind that this operating mode can be successfully used in environments where both the RS232 Wireless Adapter and the Optical Wireless Bridge are unusable allowing along with the Unconnected Mode see the relative section in this manual a full environmental investigation The devices need to communicate only during the selection of the frequency As soon as the frequency is selected you will read the message TX Tuned and Ready From now on you can remove all the connections and start the measurement You ll need to restore the communication between TX and R
28. ut with a slower series of sounds The OFF button will take the sound off The sound mode status is reported on the top of the display in this menu BEEP ON and BEEP OFF The actual threshold is written on the right top of the screen in this example is 20 dB _ 26 6 7 8 9 USER S MANUAL SEMS 3 5 Measuring the shielding attenuation Place the receiver and the transmitter on the non conductive tripods height 120 cm and place them at a distance of 40 60 cm if you are using the loop antennas and 100 200 cm if you are using biconical ones Connect the antennas upon the transmitter and receiver being careful to align themina parallel way Connect the wireless transducers to the RS232 port on the transmitter and the receiver turn on both devices and wait until the green blinking light stops and remains turned on and the two icons of the batteries become visible on the receivers display Is recommended to wait a few minutes before going on warm up Perform the zeroing procedure by using the Cal button then select Scan or List for the desired frequencies As soon as the zeroing procedure is over move the receiver into the shielded environment near the first measurement point and the transmitter outside trying to maintain the same distance used during the zeroing plus the shield width Measure the attenuation pressing the Meas Auto and 10s button to allow the user to walk away from the measuring sy
29. ync in 2 s Att 88 0 dB Abort As soon as the measurement ends you can save the data in a memory slot just like in a normal Standard measurement 94 x USER S MANUAL SEMS If you need you can start another measurement by selecting Meas again SEMS j Ready for Measuring Auto By pressing Auto you can begin a new measurement without reconnecting the two units However you can do this only for a fixed period of time see below The usage of this mode in a Wizard measurement works in a very similar way You can start a wizard zeroing sequence by selecting the list you programmed for the unconnected mode as the only range n Fully Zeroed f Ready for Measuring Auto Man PreQ Unc _35 USER S MANUAL SEMS Place the TX and RX units in the desired measurement spots and press the Unc button to enable the two units to synchronize their internal clock Note that you have to make this step while the 2 batteries are visible on the LCD display Remove Connections and start measuring Now 10s 30s Now you can remove the RS232 Wireless adapter from the RX unit you ll see the battery icon of the TX Unit that disappears close the door of the shielded environment and start measuring You ll see a countdown starting from a value that can vary according to the moment in which you started the measurement and the number of frequencies you entered in the list 5 000000 MHz Sync in 12s 36 USER S
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