SOUND LEVEL METER The 3144-20 measures and displays the spectrum and relative level of electrical noise affecting products under actual, on-site operating conditions. It also has the capability for long-term measurement data recording. Conducted interference is one type of noise that can cause problems with electronic products such as communications equipment. It propagates through communications and telephone lines and other conductors as common-mode electromagnetic noise relative to ground. Pair with Model 9741 Sensor ( included with 3144-20PRO)  Noise travels along communication wires and power lines using different paths, and problems with signal error and incorrect operation of machines caused by noise have been on the rise. By applying just the 9741 Clamp On Voltage Sensor, you can use the 3144-20 to decipher the frequency range and invasion path of the noise. Use the logging function for long-term monitoring, and transfer the recorded data to a PC via the USB interface for graphic display and printer output. • Non-contact voltage sensor • Measurement frequency range from 500Hz to 30MHz • Logging functions for long-term monitoring • Standard USB interface • Dimensions: 3.86 " W x 7.05 " H x 1.81 " D • Complete with: Clamp on Voltage Sensor 9741( 1) , AC adapter( 1) , Carrying case( 1) , PC application software CD-R( 1) , USB cable( 1) , strap( 1) , earphone( 1) , AA alkaline( LR6) batteries( 6)  • Input unit configuration: 9741 dedicated input terminal, BNC input terminal ( 9741 takes priority)  • Measurement range : × 1 range 0 dBV( 1V) f.s. ( 0 dBV to -30 dBV) .× 10 range -20 dBV( 0.1V) f.s. ( -20 dBV to -50 dBV)  • Frequency range band : 500 Hz to 30 MHz, separated into 7 ranges ( -3 dB range)  • Detection method : RMS value conversion • Detection precision : 500 Hz to 1 MHz or less ± 1.5 dBV.1 MHz to 30 MHz ± 2.0 dBV • Monitoring function : Display of measurement voltage level of each frequency range in levels on LCD ( 2.5 dBV/ SEG equivalent)  • Logging function : Measurement data and time saved to internal memory according to specified recording interval • Recording interval : 1/ 2/ 5/ 10/ 20/ 30 seconds, 1/ 2/ 5/ 10/ 20/ 30/ 60 minutes • Power supply : AA alkaline( LR6) batteries × 6, Continuous use 5 hours, included AC Adapter • Dimensions, mass : 98 mm ( 3.86 in) W × 179 mm ( 7.05 in) H × 46 mm ( 1.81 in) D, 430 g ( 15.2 oz)