{"product_id":"listen-technologies-tfsm01-fsm-field-strength-meter","title":"Listen Technologies TFSM01 – IEC 60118-4 Field Strength Meter","description":"\u003ch2\u003eProduct Overview\u003c\/h2\u003e\u003cp\u003eThe Listen Technologies TFSM01 is a magnetic field strength meter for commissioning and certifying hearing loop installations to IEC 60118-4. A hearing loop cannot be signed off by listening to it; the standard is expressed in field strength, background noise and frequency response, and all three have to be measured. This is the instrument that produces those numbers. Any integrator installing hearing loops needs one, because an accessibility consultant will ask for the measurements rather than an assurance.\u003c\/p\u003e\u003ch2\u003eProduct Description\u003c\/h2\u003e\u003cp\u003eThree measurements determine whether an installed loop meets IEC 60118-4, and the FSM covers all three.\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0603\/7982\/4364\/files\/FSM_NewLogo_5c6b2228-1f57-44b5-9bfa-c0fef80ef3bc.png?v=1787627498\" alt=\"Listen Technologies TFSM01 FSM field strength meter for hearing loop commissioning\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003cp\u003eField strength is measured broadband from 50Hz to 8kHz on a -22 to +8dB scale, with true RMS detection calibrated so that 400mA\/m reads 0dB — the reference the standard is written around. Background noise is measured A-weighted from -42 to -12dB, which is what catches an installation compromised by dimmer buzz or switch-mode noise rather than by the loop design. Frequency response is checked in third octave bands at 100Hz, 1kHz and 5kHz, which is where metal loss in the structure shows up.\u003c\/p\u003e\u003cp\u003eThe display is a flying spot LED bar graph with a wide viewing angle, colour coded green between -3dB and +3dB. That matters when you are holding the meter at head height in the middle of a room and reading it at an angle. A 3.5mm stereo output with volume control lets you listen to what is being measured, which is how you identify an interference source rather than just recording that one exists.\u003c\/p\u003e\u003cp\u003eMeter accuracy is 50Hz to 8kHz ±0.25dB, extending to 30Hz-10kHz at -3dB. It runs from two AA alkaline cells for up to 100 hours, weighs 150g and measures 84 x 27 x 140mm, so it lives in a toolbag rather than a flight case. It ships with a soft carry case, operating instructions, a commissioning guide template and test signal downloads.\u003c\/p\u003e\u003cp\u003eSignal connection cables are ordered separately as the \u003ca href=\"https:\/\/creationnetworks.net\/products\/listen-technologies-acscc-cables-for-field-strength-meter\"\u003eACSCC cable set\u003c\/a\u003e, or specify the \u003ca href=\"https:\/\/creationnetworks.net\/products\/listen-technologies-tfsm01scc-field-strength-meter-cables\"\u003eTFSM01SCC bundle\u003c\/a\u003e to get meter and cables together. Where the building structure contains significant steel, a \u003ca href=\"https:\/\/creationnetworks.net\/products\/listen-technologies-hls-2d-metal-loss-test-driver\"\u003emetal loss test driver\u003c\/a\u003e is used at survey stage to quantify the loss before the loop driver is selected.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eThree IEC 60118-4 measurements\u003c\/strong\u003e — Covers field strength, background noise and frequency response, the three the standard requires.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTrue RMS detection\u003c\/strong\u003e — Calibrated so 400mA\/m reads 0dB, the reference the standard is written around.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColour coded LED bar graph\u003c\/strong\u003e — Reads clearly at arm's length and at an angle, with green marking the -3dB to +3dB target band.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThird octave response check\u003c\/strong\u003e — Measures at 100Hz, 1kHz and 5kHz, where metal loss in the structure becomes visible.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eA-weighted background noise mode\u003c\/strong\u003e — Identifies installations compromised by dimmer or switch-mode interference rather than loop design.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAudio monitoring output\u003c\/strong\u003e — Lets the engineer hear the interference source rather than only record that one exists.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e100 hour battery life\u003c\/strong\u003e — Runs from two AA cells, so commissioning is not dependent on charge state.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eToolbag sized\u003c\/strong\u003e — 84 x 27 x 140mm at 150g, with a soft carry case included.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eTypical Applications\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eAuditorium\u003c\/li\u003e\n\u003cli\u003eHouse of worship\u003c\/li\u003e\n\u003cli\u003eGovernment space\u003c\/li\u003e\n\u003cli\u003eConference room\u003c\/li\u003e\n\u003cli\u003eTraining room\u003c\/li\u003e\n\u003cli\u003eMulti-purpose room\u003c\/li\u003e\n\u003cli\u003eCommercial meeting space\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\u003cdiv style=\"overflow-x:auto;-webkit-overflow-scrolling:touch;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;min-width:480px;\"\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:8px;border-bottom:1px solid #ddd;\"\u003eManufacturer\u003c\/th\u003e\n\u003ctd style=\"padding:8px;border-bottom:1px solid #ddd;\"\u003eListen Technologies (Ampetronic FSM)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:8px;border-bottom:1px solid #ddd;\"\u003ePart Number\u003c\/th\u003e\n\u003ctd style=\"padding:8px;border-bottom:1px solid #ddd;\"\u003eTFSM01\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:8px;border-bottom:1px solid #ddd;\"\u003eMeasurement Modes\u003c\/th\u003e\n\u003ctd style=\"padding:8px;border-bottom:1px solid #ddd;\"\u003eBackground Noise (A-weighted, -42 to -12dB), Field Strength (broadband 50Hz-8kHz, -22 to +8dB), Frequency Response (third octave at 100Hz, 1kHz, 5kHz)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:8px;border-bottom:1px solid #ddd;\"\u003eDetection\u003c\/th\u003e\n\u003ctd style=\"padding:8px;border-bottom:1px solid #ddd;\"\u003eTrue RMS, calibrated to 400mA\/m = 0dB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:8px;border-bottom:1px solid #ddd;\"\u003eFrequency Response\u003c\/th\u003e\n\u003ctd style=\"padding:8px;border-bottom:1px solid #ddd;\"\u003e50Hz to 8kHz ±0.25dB; 30Hz to 10kHz -3dB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:8px;border-bottom:1px solid #ddd;\"\u003eDisplay\u003c\/th\u003e\n\u003ctd style=\"padding:8px;border-bottom:1px solid #ddd;\"\u003eFlying spot LED bar graph, wide viewing angle, colour coded green for -3dB to +3dB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:8px;border-bottom:1px solid #ddd;\"\u003eAudio Output\u003c\/th\u003e\n\u003ctd style=\"padding:8px;border-bottom:1px solid #ddd;\"\u003e3.5mm stereo jack with volume control, 16Ω min (32Ω per side)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:8px;border-bottom:1px solid #ddd;\"\u003ePower\u003c\/th\u003e\n\u003ctd style=\"padding:8px;border-bottom:1px solid #ddd;\"\u003e2 x AA alkaline (supplied)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:8px;border-bottom:1px solid #ddd;\"\u003eBattery Life\u003c\/th\u003e\n\u003ctd style=\"padding:8px;border-bottom:1px solid #ddd;\"\u003eUp to 100 hrs use\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:8px;border-bottom:1px solid #ddd;\"\u003eDimensions\u003c\/th\u003e\n\u003ctd style=\"padding:8px;border-bottom:1px solid #ddd;\"\u003e84 x 27 x 140mm (meter only)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:8px;border-bottom:1px solid #ddd;\"\u003eWeight\u003c\/th\u003e\n\u003ctd style=\"padding:8px;border-bottom:1px solid #ddd;\"\u003e150 g excluding batteries\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:8px;border-bottom:1px solid #ddd;\"\u003eOperating Environment\u003c\/th\u003e\n\u003ctd style=\"padding:8px;border-bottom:1px solid #ddd;\"\u003e-10 to +45˚C, 10 to 85% RH\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:8px;border-bottom:1px solid #ddd;\"\u003eCompliance\u003c\/th\u003e\n\u003ctd style=\"padding:8px;border-bottom:1px solid #ddd;\"\u003eCE and UKCA marked to all relevant safety and EMC standards\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:8px;border-bottom:1px solid #ddd;\"\u003eSupplied With\u003c\/th\u003e\n\u003ctd style=\"padding:8px;border-bottom:1px solid #ddd;\"\u003eSoft carry case, operating instructions, commissioning guide template, batteries, test signal downloads\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/div\u003e\u003cp\u003e\u003cem\u003eSpecifications sourced from the Ampetronic FSM field strength meter datasheet (UP34302-12).\u003c\/em\u003e\u003c\/p\u003e\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eWhy can't a hearing loop be signed off by listening to it?\u003c\/strong\u003e\u003cbr\u003e\nIEC 60118-4 is expressed in measurable quantities: field strength relative to 400mA\/m, background noise, and frequency response across the speech band. A subjective listening check demonstrates none of those and will not satisfy an accessibility consultant or building control.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat does the meter measure?\u003c\/strong\u003e\u003cbr\u003e\nField strength broadband from 50Hz to 8kHz, background noise A-weighted, and frequency response in third octave bands at 100Hz, 1kHz and 5kHz.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDo I need the cable set as well?\u003c\/strong\u003e\u003cbr\u003e\nYes, for measurements taken at the driver. The ACSCC cable set is ordered separately, or specify the TFSM01SCC bundle to get both together.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow do I survey a building with a steel structure?\u003c\/strong\u003e\u003cbr\u003e\nMetal absorbs magnetic field strength, so the loss has to be quantified before the driver current rating is fixed. A metal loss test driver is used for that at survey stage; the field strength meter then verifies the finished installation.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is supplied with the meter?\u003c\/strong\u003e\u003cbr\u003e\nA soft carry case, operating instructions, a commissioning guide template, batteries, and access to test signal downloads.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow long does the battery last?\u003c\/strong\u003e\u003cbr\u003e\nUp to 100 hours from two AA alkaline cells, which are supplied.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat warranty and support apply?\u003c\/strong\u003e\u003cbr\u003e\nWarranty duration and technical support terms are set by Listen Technologies. Contact Creation Networks for current terms and for guidance on hearing loop commissioning procedure.\u003c\/p\u003e","brand":"Listen Technologies","offers":[{"title":"Default Title","offer_id":48228841095404,"sku":"TFSM01","price":909.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/7982\/4364\/files\/FSM_NewLogo_5c6b2228-1f57-44b5-9bfa-c0fef80ef3bc.png?v=1787627498","url":"https:\/\/creationnetworks.net\/products\/listen-technologies-tfsm01-fsm-field-strength-meter","provider":"Creation Networks","version":"1.0","type":"link"}