Contacta FSM User Manual
Contents
1. Field Strength Flat RMS Max 4 Third Octave Levels 100 200 500 1K 2 5K 5KHz B Button functions In modes 1 3 pressing the B button reset the MAX or PEAK readings In mode 4 pressing the B button advances the center frequency of the third octave filters Sensor Location Button A On Off and Mode con trol Button B Reset Select and Fre quency advance Use Menu Switch Background Noise Level Test Background Noise A Weighted Mode After turning the meter on it comes up in the Background Noise A weighted measurement mode The display will indicate the RMS reading on the first line and the MAX reading on the second line Pressing button B resets the MAX reading A RMS 42 5 dBA MAX 37 9 How to test for background noise When testing a new facility for background noise first turn on all lights fans sound system and other electrical equipment which is normally on when the facility is in use Usually the loop system has not been installed yet however if you are certifying an installation this test is done without the hearing loop system turned on Walk throughout the seating area where the loop system will be used holding the meter in a vertical position at the listening plane height The important reading will be the MAX reading Howev er itis important to watch the RMS reading If the MAX reading ex ceeds 32dBA readings above 32dBA will have a2. audio or loop level controls 100Hz 250 Hz 500 Hz 1000 Hz 2500 Hz and 5000 Hz Using the Flat Spectrum mode record the RMS level generated by each of these To meet the IEC specification the levels should not vary by any more than 3dB FS RMS 12 5 dB MAX 10 2 Method Il Pink noise signal Send a pink noise signal into the hearing loop system and select the Third Octave mode on the meter It will initially start ata 1000Hz center frequency Third Octave F 1000 Hz Pressing button B will cycle through the frequencies of 100Hz 200Hz 500Hz 1000Hz 2500Hz and 5000Hz IEC 60118 4 Notes and Requirements The standard as revised notes that within the frequencies of 100Hz to 5000Hz the hearing loop system should equally reproduce all signals Ata minimum the systems is to be tested at 100Hz 1KHz and 5KHz Program RMS Peak Levels RMS PEAK A Weighted Mode The second mode is used to set up the hearing loop signal level using an A Weighted filter It is very difficult to set the field strength to an average of 12dBA as it will constantly vary based on the program used to set up the system We will use the PEAK read ing to confirm that both our design and equipment meet the IEC specification Pressing button B resets the PEAK reading A RMS 12 5 dBA PEAK 0 2 How to test then adjust the loop system level Once the hearing loop system has been installed play some bandwidth limited 100Hz to 5KH
3. Model LOOP FSM Audio Frequency Induction Loop Field Strength Meter User Manual Contacta Model Locp FSM AFIL Hearing Loop Field Strength Meter Confirms systems meet the IEC 60118 4 standards Ref 0 d8 400mA m Reset Select Contacta inc Holland MI 616 392 3400 OY T suppont contactainc com contacta CONTENTS Meter Design goals 2 Meter Operation Basics 3 Background Noise Tests 4 Program RMS Peak Levels 5 Evaluating Frequency Response 6 Headphone Flat spectrum output 7 Line In Flat Response Meter Specifications Calibration Meter Design Goals Thank you for choosing our Field Strength Meter It has been designed to ensure that Hearing Loop Induction Loop Systems be installed and certified to the new IEC 60118 4 standard When these standards are met the user expe rience will be of equal quality wherever they have the opportunity to use their T coils Our design team interviewed many installers throughout the industry which resulted in the following design goals 1 Very accurate and easy to read 2 Simple straightforward operation 3 Based on the IEC 60118 4 specification 4 Headphone output 5 Flat spectrum output 6 Built to last and be reliable As you follow through this manual we will review how the meter should be used to certify that the requirements of the IEC specification have been met Again Thank you Contacta Design and Engineering Team Meter Spe
4. cifications Measurement Range 62dB to 9dB OdB 400mA m True RMS Crest Factor lt 3 Resolution lt 0 1dB resolution for levels over 32dB Displayed resolution 0 1 dB Detection Type True RMS on all features Sensor Pickup Coil Direction of Sensitivity Length wise of meter s longer dimension and Parallel to meter face Position noted on Product Calibration Calibrated at 1 000 Hz sine to read 0 dB at 5 03 mG Frequency Response Flat 1dB from 50 Hz to 10 000 Hz A Weighted Class 2 meter specified in IEC 61672 1 Power Source Single 9v Battery amp External Power Jack Headphone Jack Output A Weighted or Flat selectable Display 16x2 LCD Character Display Backlight Variable brightness blue LED Calibration and Warranty This meter has been calibrated with equipment that is traceable back to the National Bureau of Standards Under general use this meter should not require regular calibration however if you return the unit to Contacta the calibration can be checked and supplied with a calibration curve Please call to get a service number and check the costs involved Contacta Inc 332 E Lakewood Blvd 400 Holland MI 49424 Phone 616 392 3400 Email support contactainc com This meter is warranted to be free of component design and manufacturing defects for a period of one year Contacta accepts no responsibility for system designs or installations where this meter was used for test and calibra
5. e adjust screen where the top button raises the volume and the bottom but ton lowers it Once adjusted sliding the switch back to Use will save the setting A full flat soectrum output can be sent from this same con nector which could then feed a spectrum analyzer This would show the signal level at the various frequencies and help to both confirm proper operation and asses the frequency and level of any interfer ences To switch from A Weighted to Flat With the meter turned on slide the Use Menu switch over to Menu Press the Mode button A once and you will advance to the Headphone Jack setup screen Then pressing the Select button B you can choose either A Weighted or Flat Spectrum Menu Adjustments In the Menu mode selected by the slide switch the following items can be adjusted Backlight level Headphone output type Head phone volume Display units dB mG uT and Power timeout 5 to 30 or none Measuring Frequency Response Detailed below are two processes that can be used to con firm the system properly reproduces all of the required frequencies equally in the bandwidth of 100 to 5KHz A test signal generator such as the Contacta Loop TSG will be required to perform these tests and both methods will yield very accurate results Field Strength Flat Response Method Sine wave signal Send ata minimum the following sine wave signals through the hearing loop system without adjusting any of the
6. lower negative number ex 30dBA means there is more background noise than 35dBA you will need to document the areas where those higher noise levels are found IEC 60118 4 Notes and Requirements The standard as revised in 2004 notes that any background noise level lower than 47dBA will result in a excellent signal to noise ratio however levels below 32dBA are acceptable and do meet the requirements of the standard If the background noise lev el is above 32dBA then the facility management should be notified and the source of the interference found and repaired Method Il Pink noise signal Cont BP RMS 22 5 dB FREQ 1000 Hz Record the RMS level readings for each of the frequencies As in method if the level does not vary by more than 3dB the sys tem as installed will meet the IEC specification This method was requested by the field engineer so they could run the test with one instrument without continually adjusting the frequency source It also makes it easy to conduct the test in more than one location Headphone Full Spectrum Output The headphone output jack serves two purposes First it can be used to monitor the loop program and gives you an A Weighted output signal that can be listened to with standard 1 8 stereo head phones To change the headphone volume slide the Use Menu switch to Menu and use the Mode button to advance to Headphone Volume Pressing the Select button advances to the volum
7. tion purposes Please contact us if you have any questions Thank you 1 8 in TRS connector Line In Flat Response Mode On the top of the unit is a new feature audio dBV level The readings and the display help determine what level of signal is Coming from the house feed Levels between 10dBV and 4dBV are considered to be line level signals Often a poor loop system sound comes from a very low level facility feed This input uses the last mode on the FSM and dis plays an accurate level which can then be demon strated to the facility We prefer a level between 10dBV and OdBV To use this feature cycle through the various mode until you see Line In Flat Response on the display Now connect up the XLR adapter which has an XLR female on one end and an 1 8 TRS connector on the other end If you wish to make up your own adapter use the following information XLR female connector TID see se cece ee Pin 2 en Pin 3 Sleeve 22222020c2e2ceneseeseseseee Pin 1 Meter Operation Basics Turning the meter ON and Off On Press and hold button A until the screen lights Off Press and continue to hold button A until the Powering Down process is finished and the screen goes dark Selecting the meter mode When you press Button A it first displays the current mode and the next press advances to the next meter mode 1 Background Noise Test with Max indication 2 Signal Strength A weighted RMS Peak 3
8. z pink noise or 1KHz sine use the driver manufacturers recommendation though the loop system Walk throughout the audience area holding your meter vertically Note the readings and confirm that the A RMS level does not vary by more than 3dBA This lets you know that the perceived signal level in the hearing aids will be the same no matter where the person is sitting Next using program audio similar to what is normally used in the facility adjust the audio program level to a level just above normal Now turn on the hearing loop system and adjust the drive level until a 3dBA to OdBA PEAK level is obtained in the center of the loop Reset the PEAK level and confirm this level averages 0 dBA across the audience listening plane IEC 60118 4 Notes and Requirements The revised standard states that the signal level across the loop area should not vary by more than 3dB Once that is confirmed the signal level based on the facility s normal program should peak at 0 dB as referenced to a 400mA m This will confirm there is ade quate loop current to produce both the peak and average Avg is 12dB or 100ma m signal levels that work well with T coil equipped hearing aids
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