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Rion NA-42 Instruction Manual

Other manuals for NA-42: Instruction Manual

Summary of NA-42

  • Page 1

    3-20-41 higashimotomachi, kokubunji, tokyo 185-8533, japan http://www.Rion.Co.Jp/english/ instruction manual sound level measuring amplifi er na-42.

  • Page 3

    I organization of this manual this manual describes the features and operation of the sound level measuring amplifi er na-42. The manual contains the following sections. Outline gives basic information on the confi guration and features of the unit, and contains a block diagram. Controls and feature...

  • Page 4

    Ii to conform to the eu requirement of the directive 2002/96/ec on waste electrical and electronic equipment, the symbol mark on the right is shown on the instrument..

  • Page 5: Caution

    Iii for safety in this manual, important safety instructions are specially marked as shown below. To prevent the risk of death or injury to persons and severe damage to the unit or peripheral equipment, make sure that all instructions are fully understood and observed. Caution important d isr ega r ...

  • Page 6: Precautions

    Iv precautions operate the unit only as described in this manual. Protect the unit from shocks and vibration. Be especially careful not to touch the microphone membrane to avoid damage. The membrane is an extremely thin metal fi lm which can be damaged easily. Do not use the unit with a different mi...

  • Page 7: Caution

    V caution some pins of the input connector carry a high voltage. To prevent the risk of electric shock, never insert a metal clip or any other pointed object into the input connector..

  • Page 8

    Vi contents organization of this manual ............................................................ I for safety ............................................................................... Iii precautions .....................................................................................Iv ou...

  • Page 9

    Vii bar graph display range (20 db/50 db) setting .....................46 menu settings ..........................................................................47 external filter setting ............................................................. 52 backlight on/off ................................

  • Page 10

    Viii.

  • Page 11: Outline

    1 outline the na-42 is a sound level measuring amplifi er covering a wide frequency range and level range. It allows connection of various types of microphones such as the low-noise microphone uc-34p or the 100-khz range microphone uc-29. For general acoustic measurements and for environmental measu...

  • Page 12

    2 outline main unit block diagram over over over over over to filter from filter ac out dc out a c flat a, c flat amp amp a/d over rom cpu dsp rom i/o eep rom d/a amp amp att -20 db amp +10 db amp +20 db amp +10 db amp +20 db amp +10 db lcd driver hpf 20 hz lpf 20 khz att -10 db amp cal adj antialia...

  • Page 13

    3 outline main unit gain diagram 140 130 120 110 100 90 80 70 att 0 db -10 db -20 db amp 0 db +10 db +20 db amp 0 db +10 db +20 db amp 0 db +10 db example: sensitivity -29.9 to -20.0 l evel range (db) adjustment by cal adj (span of adjustable range: 10 db).

  • Page 14: Controls And Features

    4 controls and features front panel level range keys serve to shift the range up or down. The key switches the range up, and the key switches the range down. When the preamp power selector on the rear panel of the unit is set to ±45v, these keys are dis- abled (page 38). 20 db/50 db key toggles the ...

  • Page 15

    5 controls and features fast/slow/imp key selects the time weighting characteristics. Available settings are fast, slow, and imp (impulse). Sensitivity control serves to adjust the unit to match the microphone sensitivity. 20 khz key switches the low-pass fi lter (lpf) on and off. When the fi lter i...

  • Page 16

    6 controls and features 20 hz key switches the high-pass fi lter (hpf) on and off. When the fi lter is on, signal components below 20 hz are sharply attenuated. Lp/lmax/lpeak key switches the measurement mode to sound pressure level l p , sound level maximum l max , or peak sound pressure level l pe...

  • Page 17: Caution

    7 controls and features caution to prevent the risk of electric shock, never insert a metal clip or any other pointed object into the input connector. Setting up/down keys these keys are used for setting the microphone sensitivity or for mak- ing a selection from a menu. Sens key pressing this key a...

  • Page 18: Rear Panel

    8 controls and features rear panel battery holder four iec r14 (size "c") batteries can be inserted here. Battery holder button pressing this button sets the lid lock to on or off. Ac out connector an ac signal corresponding to the measured value is supplied at this connector. The scale range is 1 v...

  • Page 19

    9 controls and features name plate the serial number of the unit is shown here. External power supply connector the dedicated ac adapter nc-98a is connected here. Comparator output this is an open-collector output with an a contact and com contact. Preamp power selector selects ±12 v or ±45 v as pow...

  • Page 20: Display

    10 controls and features display comp appears when the comparator function is activated. The comparator function can be selected from a menu. Remote appears when the unit is in the remote mode (page 59). Over appears when the input signal has exceeded the overload threshold. When this happens, corre...

  • Page 21

    11 controls and features bar graph indicator corresponds to the level of the input signal. Peak max over "max" is shown here if the l max function is selected. When the l peak function is selected, "peak" is shown. If an overload condition has occurred for either l max or l peak , the indi- cation "...

  • Page 22

    12 controls and features level range (lower limit) the lower limit of the level range is shown here. When the bar graph range is 50 db, the value shown here corresponds to (level range -50 db). When the bar graph range is 20 db, the value shown here corresponds to (level range -20 db). Under appears...

  • Page 23: Preparations

    13 preparations power supply this unit can be operated either on four iec r14 (size c) batteries or an ac adapter (supplied accessories). Inserting batteries unlock the battery holder by pressing the battery holder button and pull out the bat- tery holder. After replacing the batteries, push the bat...

  • Page 24: Battery Life

    14 preparations battery life alkaline batteries lr14 approx. 14 hours manganese batteries r14p approx. 6 hours • the above values were determined under the following conditions. 20°c 50% rh, microphone uc-53a, preamplifi er nh-17, power supply for preamplifi er ±12 v, backlight off, communications o...

  • Page 25: Important

    15 preparations microphone and preamplifi er connection the proper selection of microphone and preamplifi er depends on various factors, such as the level to be measured, frequency range, purpose of the measurement, etc. (for details, see the section "technical reference" start- ing on page 81.) con...

  • Page 26: Important

    16 preparations 1) using the microphone uc-53a and preamplifi er nh-17 1. Mount the microphone uc-53a on the preamplifi er nh-17. Important the microphone is a precision instrument that must be protected from shocks. If the micro- phone is accidentally dropped, sensitivity and frequency response may...

  • Page 27: Important

    17 preparations 2) using the uc-34p (microphone uc-34, preamplifi er nh-34) 1. Mount the microphone uc-34 on the preamplifi er nh-34. Important the microphone is a precision instrument that must be protected from shocks. If the micro- phone is accidentally dropped, sensitivity and frequency response...

  • Page 28

    18 preparations 3. Using the optional condenser microphone extension cable series ec- 04, connect the preamplifi er to the na-42. 4. Turn the unit on and activate menu 1. Note menu 1 serves to set the preamplifi er gain. When preamplifi er gain is set to 20 db, the lower mea- surement limit will be ...

  • Page 29: Important

    19 preparations 3) using the microphone uc-29 and preamplifi er nh-05 1. Mount the microphone uc-29 on the adapter ua-12, and then mount the assembly on the preamplifi er nh-05. Important the microphone is a precision instrument that must be protected from shocks. If the micro- phone is accidentally...

  • Page 30: Calibration

    20 preparations calibration before starting a measurement, the unit must be calibrated. There are three types of calibration. 1) electrical calibration with a tone from a built-in signal generator 2) calibration with a pistonphone or a sound calibrator 3) insert cal calibration after turning on the ...

  • Page 31

    21 preparations the sensitivity setting is the microphone sensitivity plus the pream- plifi er loss. The microphone sensitivity is the value given on the calibration chart attached with the microphone (see below). The preamplifi er loss (caused by static capacitance of microphone and preamplifi er) ...

  • Page 32

    22 preparations note when the 0.1 db readout resolution has been chosen with menu 3, the sensitivity setting range extends to fi rst decimal place. When the 0.01 db readout resolution has been chosen, the sensitivity setting range extends to second decimal place. If the sensitivity has been set with...

  • Page 33

    23 preparations 7. Use the supplied screwdriver to adjust the sensitivity control on the front panel to the calibration value (under 6 db of the level range value). Cal fast c calibration value level range value measurement value calibration example for level range 100

  • Page 34: Important

    24 preparations 2) calibration with pistonphone nc-72 or sound calibrator nc-74 for this type of calibration, the pistonphone nc-72 or sound calibrator nc-74 is mounted on the microphone and the sensitivity control is adjusted so that the sound pressure level indication matches the sound pressure le...

  • Page 35

    25 preparations 4. Use the setting ( , ) keys to adjust the sensitivity. The microphone sensitivity is the value given on the calibration chart accompanying the microphone (see below). The preamplifi er loss (caused by static capacitance of microphone and preamplifi er) is as shown in the table belo...

  • Page 36

    26 preparations 5. Press the sens key on the front panel to return to the measurement screen. 6. Use the level range keys to set the level range to "100" if the nc-74 is used, or to "120" if the nc-72 is used. 7. When a 1/2-inch condenser microphone is used for calibration, mount the 1/2-inch adapte...

  • Page 37

    27 preparations 10. Use the supplied screwdriver to adjust the sensitivity control to the specifi ed value. When using the sound calibrator nc-74, the calibration values are as follows. When using the pistonphone nc-72, adjust the control to the output sound pressure level value shown on the pistonp...

  • Page 38

    28 preparations note for details on operation of the nc-74 or nc- 72, please refer to the instruction manual for them. For information about compensation for atmospheric pressure, please refer to the docu- mentation of the pistonphone nc-72. The nc-74 is designed to produce 94.0 db under its rated c...

  • Page 39: 3) Insert Cal Calibration

    29 preparations 3) insert cal calibration the na-42 allows calibration using the "insert cal" method. For this method, a dedicated preamplifi er is used. 1. Turn power to the na-42 off and connect the insert cal preampli- fi er nh-08 and the microphone. 2. Turn power to the na-42 on. 3. Press the me...

  • Page 40

    30 preparations 8. Press the cal key to activate the calibration mode. Measurement parameters are automatically set to c weighting and fast. 9. Use the supplied screwdriver to adjust the sensitivity control on the front panel to the calibration value (94.0 db in the example shown above). Cal fast c ...

  • Page 41

    31 preparations signal output for calibrating external devices to enable calibration of external devices, a calibration signal can be output also for level ranges other than the range selected during calibration. Before calibrating external devices, calibration of the na-42 as described in the secti...

  • Page 42

    32 preparations 2. Set the level range to 120 and press the cal key. 3. The ac out and dc out connectors carry a signal that corre- sponds to the displayed measurement value. (the ac output signal is a 1 khz sine wave signal.) use this signal to calibrate the external device. Using the level recorde...

  • Page 43: Using A Tripod

    33 preparations using a tripod when mounting the microphone on the optional tripod, fi rst fasten the mi- crophone holder to the tripod. Microphone holder ua-90 nh-17, nh-11, nh-12 ec03001 nh-01, nh-04, nh-05, nh-06, nh-34 the ec03001 is supplied with the condenser microphones ec-04, ec-04a, and ec-...

  • Page 44: Using A Windscreen

    34 preparations using a windscreen when making outdoor measurements in windy weather or when measuring air conditioning equipment or similar, wind noise at the microphone can cause measurement errors. To prevent this, an optional windscreen can be mounted to the microphone. For details on the effect...

  • Page 45: Using The Prop-Up Feet

    35 preparations using the prop-up feet the unit can be tilted by fl ipping out the prop-up feet. Tilt the feet until they snap in place. Important when using the prop-up feet, do not place objects on top of the na-42 and do not push down on the unit. Do not push prop-up feet.

  • Page 46: Measurement

    36 measurement power-on important preamplifi er power supply normally, the preamp power selector on the rear panel should be set to ±12 v. If wishing to set the selector to ±45 v, fi rst make sure that the preamplifi er (microphone) is compatible with this voltage. Preamplifi ers compatible with bot...

  • Page 47

    37 measurement when the unit is turned on, the same settings as used before the unit was turned off are reestablished (resume function), and measurement starts. After turning on the unit, wait at least 2 minutes to let the circuits stabilize, and start measurement only after calibration was complete...

  • Page 48: Level Range Setting

    38 measurement level range setting setting procedure use the level range keys to select an appropriate setting, where the over or under indication does not appear in normal operation. If the input signal level is too high for the selected range, the indication over appears. In this condition, correc...

  • Page 49: Setting Procedure

    39 measurement frequency weighting setting available frequency weighting settings are a weighting, c weighting, and flat. Setting procedure press the a/c/flat key to select the desired setting. Each push of the key cycles through the following settings: a c flat a. For noise measurements, the "a" se...

  • Page 50: Time Weighting Setting

    40 measurement time weighting setting available time weighting settings are fast, slow, and imp (impulse). Setting procedure press the fast/slow/imp key to select the desired setting. Each push of the key cycles through the following settings: fast slow imp fast. For normal measurements, the "fast" ...

  • Page 51: / L

    41 measurement l p / l max / l peak setting the measurement mode can be set to l p (sound pressure level), l max (sound level maximum) or l peak (peak sound pressure level) l max (sound level maximum) 1. Press the lp/lmax/lpeak key to select the l max setting. The indica- tion "max" appears on the d...

  • Page 52: (Peak Sound Pressure Level)

    42 measurement 4. The reset key can be used to reset the hold value. L peak (peak sound pressure level) 1. Press the lp/lmax/lpeak key to select the l peak setting. The indica- tion "peak" appears on the display. The input waveform peak value is held, using 250 khz sampling. Sound level measuring am...

  • Page 53

    43 measurement 2. When the l peak function is selected, the peak sound pressure level of the measurement value is held. The display is updated whenever a higher value is input. 3. If the hold value has caused overload, peak over is shown. 4. The reset key can be used to reset the hold value. Over sl...

  • Page 54: Low-Pass Filter Setting

    44 measurement low-pass filter setting the low-pass fi lter has a cutoff frequency of 20 khz. Setting procedure press the 20 khz key to toggle the 20 khz low-pass fi lter between on and off. When the setting is on, signal components above 20 khz are sharply attenuated. For details on low-pass fi lte...

  • Page 55: High-Pass Filter Setting

    45 measurement high-pass filter setting the high-pass fi lter has a cutoff frequency of 20 hz. Setting procedure press the 20 hz key to toggle the 20 hz high-pass fi lter between on and off. When the setting is on, signal components below 20 hz are sharply attenuated. For details on high-pass fi lte...

  • Page 56: Setting Procedure

    46 measurement bar graph display range (20 db/50 db) setting the bar graph display range can be set to 20 db or 50 db. Setting procedure press the 20 db/50 db key to toggle between the two settings. Each push of the key switches between the following settings: 20 db 50 db 20 db etc. 20 db range: bar...

  • Page 57: Menu Settings

    47 measurement menu settings settings for preamplifi er gain, insert on/off, measure- ment value readout resolu- tion, serial communication, and comparator measurement conditions are made using menus. Setting procedure 1. Press the menu (light) key. Note pressing the menu (light) key will not bring ...

  • Page 58

    48 measurement each push of the menu (light) key cycles through the following menu numbers: 1 2 3 4.0 (4.1 4.2)* 1 5.0 (5.1 5.2 5.3 5.4)* 2 measurement screen *1 appear when 9600 or 19200 was set with menu 4.0. *2 appear when menu 5.0 is set to on. 3. Select the desired menu with the menu (light) ke...

  • Page 59: Menu Setting Contents

    49 measurement menu setting contents menu 1 preamplifi er gain 0 db/20 db when set to 20 db, pin e of the input connector carries a micro- phone bias voltage of 30 v. 0 db : this setting should be selected normally. 20 db : select this setting if the uc-34p (uc-34, nh-34) is con- nected and low-leve...

  • Page 60: Important

    50 measurement note the sensitivity setting range also changes with the 0.1 db/0.01 db setting. Menu 4.0 controls the setting for serial communication. Off : serial communication is not used. 9600 : serial communication is used, and transfer rate is set to 9600 bps. 19200 : serial communication is u...

  • Page 61

    51 measurement note when menu 4.0 is set to off, menus 4.1 and 4.2 are not shown. Menu 5.0 sets the comparator to on or off. : comparator function is disabled. : comparator function is enabled. Menu 5.1 sets the comparator level. The comparator level setting range is 0 to 180 db, in 1-db steps. Menu...

  • Page 62: External Filter Setting

    52 measurement external filter setting to use an externally connected fi lter, press the ext filter key. 1. Connect the external fi lter or similar component to the connectors on the rear panel. 2. Press the ext filter key to route the signal through the external fi lter. Serial comp out ±12v ±45v p...

  • Page 63: Backlight On/off

    53 measurement backlight on/off press and hold the menu (light) key for at least 2 seconds to set the lcd backlight to on or off. When set to on, the backlight will make the screen easy to read also in dark locations. Note when the unit is running on batteries, the backlight is automatically turned ...

  • Page 64: Comparator

    54 comparator the various settings for the comparator function are made via menu screens (see "menu settings" on page 51) setting items comparator level 0 to 180 db in 1 db steps delay time 0 to 9 seconds in 1 s steps auto reset function auto reset time 0 to 90 seconds in 1 s steps comparator operat...

  • Page 65

    55 comparator while comparator function is operating, the indication comp is shown. In the bar graph indication, the bar corresponding to the comparator refer- ence level remains constantly on. For example, when the comparator level is set to 75 db, the 75 db point on the bar graph scale lights up. ...

  • Page 66: Auto Reset Function

    56 comparator auto reset function the auto reset function is set with menu 5.3 ( "menu settings", p. 51). When set to on, the comparator output, once triggered, will be reset after the time set with menu 5.4 when the sound pressure level remains below the comparator level for an extended time. When ...

  • Page 67: Comparator Output

    57 comparator reset operation when the comparator output was activated, it can be reset in three ways. (1) auto reset as described above, when auto reset is on, the comparator output will be reset automatically after activation when the auto reset time has elapsed. (2) reset key pressing the reset k...

  • Page 68: Serial Interface

    58 serial interface the na-42 incorporates a serial interface that can be used to set measurement parameters and control measurement using commands sent from a computer. Measurement results can also be sent to the computer. Using sc-31m or sc-31s adapters (option), a single computer can be used to c...

  • Page 69: Local Mode/remote Mode

    59 serial interface local mode/remote mode local mode in this mode, the controls on the panel of the na-42 are used to op- erate the unit. Immediately after being turned on, the unit is always in local mode. Remote mode in this mode, the na-42 operates in response to commands sent from a computer. O...

  • Page 70

    60 serial interface 1:n connection when connecting multiple na-42 units (up to 16) to one computer, the optional sc-31m/sc-31s adapters and lan cables (generic 10base-t cable) are required. Connection example maximum allowable wiring distance: 400 m 3. Set the power switch of the na-42 to on. 4. Mak...

  • Page 71: Transfer Sequence

    61 serial interface transfer sequence sending of commands in order to control the na-42 from a computer or to retrieve measurement data, certain commands must be sent to the na-42. The data exchange must be performed according to certain rules, to ensure that both the na-42 and the computer recogniz...

  • Page 72

    62 serial interface ** is the id number. Ack>: control code 06 h (acknowledge) cr>: control code 0d h (carriage return) lf>: control code 0a h (line feed) eot>: control code 04 h (end of transfer) ready: ascii string (command): ascii string (command and parameters) (data): ascii string (data request...

  • Page 73: Error Processing

    63 serial interface error processing in order to ensure correct data exchange between the na-42 and the computer, the rules described above must be observed. If an error occurs, the following steps should be taken. The computer has sent rmt1 ** cr>lf> but the remote indica- tor on the na-42 does not...

  • Page 74: Command Format

    64 serial interface command format commands that can be used by the na-42 consist of 3 characters (3 bytes), usually followed by a parameter which specifi es the action range of the com- mand. There are two types of parameters: • parameters for changing function settings • parameter for requesting d...

  • Page 75: Command List

    65 serial interface command list rmtn1n2n3 rmt? Rngn rng? Tmcn tmc? Wgtn wgt? Snsn1n2n3n4n5 sns? Lpfn lpf? Hpfn hpf? Extn ext? Caln cal? Bat? Dod? Dofn set l max function to on/off maxn max? Pekn pek? Rst 67 67 67 68 68 68 68 69 69 69 70 70 67 68 71 71 69 69 69 69 70 70 72 72 72 72 72 select local m...

  • Page 76

    66 serial interface cmpn cmp? Cmsn1n2n3n4n5n6n7 cms? Ver? Pren pre? Insn ins? Barn bar? Dctn dct? 73 73 73 74 72 72 73 74 74 74 74 74 74 set comparator function to on/off get comparator function status make comparator function settings get comparator function settings get version information set pre...

  • Page 77: Commands

    67 serial interface commands rmt n1 n2 n3 select local mode/remote mode n1 = 0 local mode n1 = 1 remote mode n2 n3 = 00 to 15, ff set id number. Na-42 specifi ed by id number receives the command. Ff specifi es all connected na-42. To send a setting command to all connected na-42 units when using th...

  • Page 78

    68 serial interface tmc n set time weighting for main processing n=0 fast n=1 slow n=2 imp tmc? Get time weighting setting output data format p eot>cr>lf> p corresponds to n of tmc wgt n set time frequency weighting n=0 a weighting n=1 c weighting n=2 flat response wgt? Get time frequency weighting ...

  • Page 79

    69 serial interface sns? Get sensitivity setting output data format p1p2p3p4p5 eot>cr>lf> for setting the sensitivity down to one decimal point when the readout resolution is set to one decimal point, p5 becomes "0". Lpf n set low-pass fi lter setting n = 0 off n = 1 20 khz lpf ? Get low-pass fi lte...

  • Page 80

    70 serial interface cal n set calibration mode n = 0 calibration off n = 1 calibration on cal? Get calibration mode status output data format p eot>cr>lf> p = 0 calibration off p = 1 calibration on bat? Get battery capacity status output corresponds to status of battery capacity indicator on display...

  • Page 81

    71 serial interface · when readout resolution is set to two decimal points p1 p2 p3 p4 p5 p6,p7 eot>cr>lf> p1 to p6 : indicated measurement value p4 : taken as "." when the integer is 1 or 2 digits, the empty p1 and/or p2 part is padded with spaces. When there is no displayed measurement value and t...

  • Page 82

    72 serial interface max n set l max (sound level maximum) function to on/off n = 0 maximum hold off n = 1 maximum hold on max? Get l max function status output data format p eot>cr>lf> p = 0 l max off p = 1 l max active pek n set l peak (peak sound pressure level) function to on/ off n = 0 l peak of...

  • Page 83

    73 serial interface cms n1 n2 n3 n4 n5 n6 n7 make comparator function setting n1 to n3: set comparator level to 000 to 180 n1 is the fi rst digit, n2 the second digit and n3 the third digit. When the setting value is only 1 or 2 digits, the empty part is padded with zeros. Make comparator function s...

  • Page 84

    74 serial interface pre? Get preamplifi er gain and setting of rear-panel preamp power selector p1p2 eot>cr>lf> p1 corresponds to n of pren p2 = 0 ±12 v p2 = 1 ±45 v insn set insert cal n = 0 off n = 1 on ins? Get insert cal setting output data format p eot>cr>lf> p corresponds to n of ins barn set ...

  • Page 85: Dof Transfer Sequence

    75 serial interface dof transfer sequence the instantaneous value sound pressure level output updated every 0.1 seconds stops when sub> or dof0cr>lf> is input. Normally sub> should be used, because the chance for communication errors is lower. Sub> : control code 1a h note because this unit supports...

  • Page 86: Conditions

    76 serial interface l max l peak rmt0n2n3 dcl dod? Dofn sub> rngn tmcn wgtn lpfn hpfn extn maxn pekn caln snsn1 to n5 rst barn cmpn cmsn1 to n7 dctn insn pren command calibration comparator dof operation normal measurement content: others related commands content: data related commands content: fron...

  • Page 87

    77 serial interface ver? Rmt? Bat? Rng? Tmc? Wgt? Lpf? Hpf? Ext? Max? Pek? Sns? Cal? Bar? Cmp? Cms? Dct? Ins? Pre? × × × × × × × × × × × × × × × × × × × l max l peak command calibration comparator dof operation content: others related commands (with ?) content: front panel key related commands (with...

  • Page 88

    78 serial interface communication with multiple units using sc-31 using the optional sc-31m/sc-31s adapters, it is possible to connect up to 16 na-42 units to a single computer. Connecting multiple na-42 units (max. 16) to a computer use sc-31m/sc-31s adapters (option) and lan cables (generic 10base...

  • Page 89

    79 serial interface sending commands to a single unit when multiple units are connected, but you want to communicate only with a specifi c unit, proceed as follows. The procedure is the same as when com- municating on a 1-on-1 basis. 1. Send the rmt0ff command from the computer to set all na-42 unit...

  • Page 90

    80 serial interface sending commands to all connected na-42 units when sending commands to all connected units, only commands for chang- ing settings are allowed. 1. Send the rmt1ff command from the computer to set all na-42 units to remote mode (link established). 2. Use the necessary setting comma...

  • Page 91: Technical Reference

    81 technical reference microphone and preamplifi er selection when making measurements using a condenser microphone and preamplifi er combination, suitable models must be selected according to the measurement level, frequency range, and other factors. Condenser microphones (sample listing) preamplif...

  • Page 92

    82 technical reference uc-26 uc-28 uc-30 uc-31 uc-33p uc-52 uc-53a ua-31 ws-02 ws-05 uc-29 ua-12 nc-72 nc-72-s06 nc-73 nc-71-s02 nc-72 nc-72-s16 nc-72 nc-73 nc-74 ua-30 ws-01 uc-24 uc-27 uc-32p ua-10 m o de l :nc- 7 4 s e r n o .** *** rion co. ,l t d. Ma d e in j a p a n m ode l :nc- 7 4 s e r n o ...

  • Page 93

    83 technical reference ua-20 ua-20 ua-20 ua-20 ua-20 nh-05 nh-12 2.5 m nh-17a nh-04 nh-01 nh-04 nh-06 nh-11 2.5 m nh-12 2.5 m nh-17 5 m ec-04 2 m ec-04a 5 m ec-04b 10 m 20hz 20khz na-42 ec-04c 30+5 m ec-04d 50+5 m ec-04e 100+5 m flexible rod preamplifier extension cable multiple extension cables can...

  • Page 94: Measurement Range

    84 technical reference measurement range the frequency range and linear operation range depend on the microphone and preamplifi er. Frequency range the frequency range that can be measured depends on the microphone, as shown in the graph below. Linear operation range the linear operation range depen...

  • Page 95: Microphone

    85 technical reference microphone there are various ways to convert sound pressure changes into electrical signals. For acoustic measurements, the condenser (electrostatic) microphone principle is widely used, because it offers high stability, fl at frequency re- sponse, high sensitivity and allows ...

  • Page 96

    86 technical reference the upper frequency limit means that sensitivity is decreased. The tuning of microphone frequency response is achieved by opening a number of holes in the backplate in order to adjust the viscous resistance (damping characteristics) of the air that moves between the diaphragm ...

  • Page 97: Important

    87 technical reference the microphone uc-34 is made out of the following materials: titanium (chassis), titanium alloy (diaphragm), and silicone-impregnated and quartz- coated steatite (insulators). The main specifi cations of the microphone are shown in the table below. Main specifi cations of micr...

  • Page 98: Preamplifi Er

    88 technical reference preamplifi er since the capacitance of a condenser microphone is low (in the range of several picofarads to several tens of picofarads), its impedance is very high, especially at low frequencies. In order to achieve usable frequency response down to low frequencies, the load i...

  • Page 99: Insert Cal

    89 technical reference insert cal by using the dedicated preamplifi er nh-08, the na-42 allows highly accurate calibration comprising the microphone and preamplifi er (insert cal). Insert cal function the microphone sensitivity is determined under the assumption that the mi- crophone is connected to...

  • Page 100: Extension Cable

    90 technical reference extension cable after impedance conversion by the preamplifi er, the signal from the micro- phone is fed through an extension cable to the sound level meter. The fol- lowing extension cables are available as options. Although the output impedance of the preamplifi er is low, t...

  • Page 101

    91 technical reference measurement sound pressure level and measurement frequency for extension cable capacitances example using the microphone uc-34p with a sensitivity level of -21 db to measure a sound pressure level of 95 db up to 10 khz, the maximum allowable exten- sion cable length is about 2...

  • Page 102: Windscreen

    92 technical reference windscreen during outdoor measurements, wind noise can falsify measurement results. To counter such problems, an optional windscreen should be mounted on the microphone. The characteristics of the windscreen ws-01 and ws-02 are shown in the fi gures below and on the next page....

  • Page 103

    93 technical reference frequency response of wind noise measured with windscreen ws-01/ws-02 mounted to microphone infl uence of windscreen ws-01/ws-02 on acoustical properties of microphone (referred to microphone response without windscreen) 90 80 70 60 50 40 20 30 50 70 100 200 300 600 700 1 k 15...

  • Page 104

    94 technical reference infl uence of background noise when measuring a certain sound in a certain location, all other sound present at that location except the measurement target sound are background noise (also called background). Since the sound level meter will display the com- bination of target...

  • Page 105: Frequency Weighting

    95 technical reference frequency weighting the na-42 provides a choice between a and c weighting and flat fre- quency response. The electrical characteristics of the weighting circuitry are as shown below. The volume impression (loudness) of a sound depends not only on the sound pressure level, but ...

  • Page 106: Input Connector

    96 technical reference input connector the input connector is a tajimi electronics 7-p connector (1008-23a10-7f). The pin assignment is as follows. A: preamplifi er power supply +12 v / +45 v b: ground c: signal input d: preamplifi er power supply -12 v / -45 v e: 30 v dc / ground / calibration sign...

  • Page 107

    97 technical reference rms detection circuit and time weightings the noise level meter uses rms detection. The effective value e (rms) is de- fi ned by the following equation. The voltage e which changes over time is raised to the power of 2, and integra- tion for the time interval t is performed. T...

  • Page 108

    98 technical reference during noise level measurements, the level often fl uctuates drastically, which would make it diffi cult to evaluate readings without some kind of averag- ing. Sound level meters therefore provide the capability for index weighting (index averaging) using the rms circuit. The ...

  • Page 109

    99 technical reference time weightings and time constant the time weighting circuit of the noise level meter performs index averaging on the square of the sound pressure signal. The equiva- lent circuit is shown at right. Is the time constant, which equals cr. E i : input voltage (proportional to sq...

  • Page 110: Factory Default Settings

    100 technical reference factory default settings the factory default settings are listed below. To reset the unit to these settings, turn the unit off, and then hold down the reset key while turning the power on. (the rear-panel preamp power selector setting and the microphone sensitivity setting ar...

  • Page 111: Rack Mounting

    101 technical reference displaying the software version to display the software version, turn the unit off, and then hold down the menu (light) key while turning the power on. The software version is shown in the measurement value fi eld. Rack mounting the unit can be mounted in a rack, using the fo...

  • Page 112: Na-42Pb1

    102 technical reference na-42pb1 the na-42 management software na-42pb1 is designed for use with the sound level measuring amplifi er na-42. The software allows setting measure- ment parameters and controlling measurement operation by means of com- mands sent from the computer. Measurement result da...

  • Page 113

    103 technical reference main menu screen measurement screen.

  • Page 114: Specifi Cations

    104 specifi cations measurement functions sound pressure level l p sound level maximum l max maximum sound level value is held on measurement value readout. Peak sound pressure level l peak peak sound pressure level value is held on measurement value read- out. Sampling frequency 250 khz frequency r...

  • Page 115

    105 specifi cations residual noise input converted inherent noise a weighting: 1.5 µv rms or less c weighting: 1.5 µv rms or less flat characteristics: 7 µv rms or less flat (hpf 20 hz, lpf 20 khz): 2.5 µv rms or less linearity range 60 db level range switching 10 db steps maximum 8 steps setting ra...

  • Page 116

    106 specifi cations time weighting fast, slow, impulse rms detection by digital processing built-in fi lters high-pass fi lter (hpf): 3rd-order butterworth fi lter, 20 hz (-3 db) low-pass fi lter (lpf): 3rd-order butterworth fi lter, 20 khz (-3 db) calibration electrical calibration using 1-khz sine...

  • Page 117

    107 specifi cations dc output bnc connector output voltage: 6 v (at full-scale of range), 1 v/10 db output impedance: 50 Ω load impedance: 10 kΩ or more external fi lter input bnc connector output impedance: 600 Ω input impedance: 100 kΩ serial communication for setting control from computer and dat...

  • Page 118

    108 specifi cations display backlit lcd numeric readout 5 digits, display range 70 db second decimal place or fi rst decimal place, switchable display update interval 1 s for fi rst decimal place readout resolu- tion 0.2 s for second decimal place readout resolution bar graph scale range 50 db or 20...

  • Page 119

    109 specifi cations power requirements iec r14 (size "c") batteries × 4 (r14p or lr14) battery life lr14: approx. 14 hours * r14p: approx. 6 hours * * measurement conditions ambient temperature 23ºc, using microphone uc-53a and preamplifi er nh-17, preamplifi er power supply voltage ±12 v, backlight...

  • Page 120

    110 specifi cations supplied accessories iec r14 (size "c") batteries r14p 4 ac adapter nc-98a 1 miniature screwdriver d-62 1 storage case vm-83-031 1 instruction manual 1 inspection certifi cate 1 optional accessories external input adapter ua-01 condenser microphones preamplifi ers condenser micro...

  • Page 121

    111 specifi cations unit: mm dimensional drawings sound level measuring amplifier hpf lpf level range cal 20db/50db power ext filter reset lp/lmax / lpeak on input na-42 adj sens menu (light) fast a/c /flat /slow /imp 20hz 20khz 171 120 serial comp out ±12v ±45v preamp a com lock unlock batt box ac ...

  • Page 122

    No. 32342 06-12 printed in japan.