2015, 2015-P, 6-Digit THD Multimeters 2016, 2016-P 6-Digit Audio Analyzing Multimeters The Models 2015-P and 2016-P Audio Analyzing Digital Multimeters and the Models 2015 and 2016 Total Harmonic Distortion Multimeters combine audio band quality measurements and analysis with a full-function 6-digit DMM . Test engineers can make a broad range of voltage, resistance, current, frequency, and distortion measurements, all with the same compact, half-rack measure- ment instrument . The Model 2016 and 2016-P have twice the sine wave generator output of the Model 2015 for applications that require test signals greater than 8Vrms . The Model 2015-P and 2016-P offer additional processing capacity for frequency spectrum analysis . f requency Domain Distortion analysis For applications such as assessing non-linear distor- tion in components, devices, and systems, DSP- based processing allows the Models 2015-P, 2015, 2016, and 2016-P to provide frequency domain anal- ysis in conventional time domain instrumen ts . They can measure Total Harmonic Distortion (THD) over the complete 20Hz to 20kHz audio band . They THD, THD+Noise, and sINaD also measure over a wide input range (up to 750Vrms) and have low residual distortion (87dB) . The measurements THD reading can be expressed either in decibels or as a percentage . 20Hz20kHz sine wave In addition to THD, the Models 2015, 2015-P, 2016, and 2016-P can comp ute THD+Noise and Signal- generator to-Noise plus Distortion (SINAD) . For analyses in which the individual harmonics are the criteria of f ast frequency sweeps greatest interest, the instruments can report any of the (up to 64) harmonic magnitudes that can be included in the distortion measurements . The user can program the actual number of harmonics to 2015-P, 2016-P: Identifies peak be included in a computation, so accuracy, speed, and complexity can be optimized for a specific spectral components application . (See Figure 1 . ) 2015, 2015-P: 4Vrms single- ended or 8Vrms differential f igure 1. f requency spectrum of 1kHz square Wave output 0.35 2016, 2016-P: 9.5Vrms single- ended or 19Vrms differential 0.3 output 0.25 Individual harmonic magnitude measurements 0.2 5 standard audio shaping filters Ratio to Fundamental 13 DMM functions (6 digits) 0.15 GPIb and rs -232 interfaces 0.1 0.05 aPPl ICaTIoNs Wireless communication device 0 audio quality testing 23456789 10 11 12 13 14 15 16 17 18 19 20 21 Component linearity testing Harmonic l ighting and ballast THD limit conformance testing Figure 1 shows a plot of a square waves harmonics (frequency components) computed and transmitted to a personal computer by the Model 2015 or 2016. a square waves spectral Telephone and automotive content consists of only odd harmonics whose magnitudes are (1/harmonic number the 1 speaker testing 3 the magnit ude of the fundamental). f or example, the magnitude of the third harmonic is magnitude of the fundamental. 1.888.KEITHLEY (U.S. only) www.keithley.com A Greater Measure of Confidence Audio analyzing and total harmonic distortion DMMs DIGITAL MULTIMETERS & SYSTEMS Audio analyzing and total harmonic distortion DMMs2015, 2015-P, 6-Digit THD Multimeters 2016, 2016-P 6-Digit Audio Analyzing Multimeters f igure 3. THD and 2nd, 3rd, and 4th Harmonics as a f unction of f requency ordering Information 0 2015 Total Harmonic THD: 10 Distortion 6-Digit Levels relative to fundamental: 2nd harmonic Multimeter 20 3rd harmonic 4th harmonic 2015-P audio analyzing DMM 30 2016 Total Harmonic 40 Distortion 6-Digit relative DMM w/9V output 50 level source o utput (db) 60 2016-P audio analyzing DMM w/9V source o utput 70 80 accessories supplied Model 1751 safety Test l eads, 90 user Manual, service Manual. 100 1001000 10000 frequency (Hz) f igure 2. Total Harmonic Distortion f igure 4. f requency r esponse analysis and f requency 10 r esponse of a Portable Wireless Telecommunication Device Device Under Test 5 0 Output relative Transducer output 5 (db) Input Transducer 10 Source Signal 15 Output Input 2015 MULTIMETER 20 1001000 10000 frequency (Hz) Model 2015, 2015-P, 2016, or 2016-P o ptimized for Production Testing Figures 2, 3, and 4 demonstrate how the Model 2015, 2015-P, 2016, or 2016-P can The Models 2015, 2015-P, 2016, and 2016-P can perform fast frequency sweeps for characterizing provide both time domain and frequency audio-band circuitry in production test systems . For example, the instruments can execute a single domain measurements in a single test sweep of 30 frequencies and transmit both rms voltage readings and THD readings to a computer in protocol. Figure 2 shows a s ample test system schematic with a telecommunication only 1 . 1 seconds . With that data, a complete frequency response analysis and a harmonic distortion device in a loop back mode test. The audio vs . frequency analysis can be performed in a very short time . Thus high speed testing of the audio analyzing DMMs source provides a stimulus performance of a high volume device such as a cellular telephone can be performed without reducing f requency sweep, and the audio analyzing the number of tests or reducing the measurements in each test . With these instruments, which are DMM measures the response from the optimized for production testing, test engineers can lower test times, in comparison to test speeds microphone circuit. Figure 3 shows the resulting frequency domain analysis of achievable with general purpose audio analyzers, without sacrificing production test quality . the THD and the first three harmonics as a function of frequency. Figure 4 shows the Dual o utput source time domain analysis of micro phone circuit The Models 2015, 2015-P, 2016, and 2016-P include an internal audio band sine wave source for gen- output voltage as a function of frequency. erating stimulus signals . A second output, the inverse of the first output, is also available, simplifying the testing of differential input circuits for common mode or noise cancellation performance . 1.888.KEITHLEY (U.S. only) www.keithley.com A Greater Measure of Confidence Audio analyzing and total harmonic distortion DMMs DIGITAL MULTIMETERS & SYSTEMS Audio analyzing and total harmonic distortion DMMs