AUTORANGING AC VOLTMETER NOISE METER
Contents
1. 3 6 Block it laica 4 1 Silk diagram of PCB viewed from above with top cover removed 5 5 JIS C1502 JIS A characteristics 7 2 JIS C1502 JIS C characteristics 7 2 CCIR ARM characteristics diagram 7 3 DIN 45405 AUDIO characteristics diagram 7 3 DIN 45405 NOISE characteristics diagram 7 4 CCIR characteristics diagram 7 4 IHF BPF characteristics diagram 7 5 vi Table 2 1 Table 5 1 M2177 Tables Page Component OE Re een 2 1 Reference levels of standard equipped weighting filters 5 2 1 M2177 1 1 1 2 1 3 1 4 General Description OUTING LEE 1 1 Features ciii eid a ii ei e t 1 1 APPIICATIONS itor 1 1 Specifications rr AEA 1 2 1 44 Electrical ratings eot 1 2 1 4 2 Mechanical ratings 1 4 1 4 3 Installation requirements 1 4 1 44 Options saisi eerte a Renee tete ast 1 5 1 1 Outline Y 1 1 Outline The M2177 A2. THI THI HII ZI E ME Frequency Hz Bu Figure 7 1 JIS C1502 JIS A characteristics diagram BE OTT po 1102 a Hz Figure 7 2 JIS C1502 JIS C characteristics diagram M2177 7 2 M2177 7 2 Standard Data LLLI EDU LLL LL E 1 EDI L TILL TT Frequency Hz Figure 7 3 CCIR ARM characteristics diagram Frequency Hz Figure 7 4 DIN 45405 AUDIO characteristics diagram 7 3 7 2 Standard Data Frequency Hz Figure 7 5 DIN 45405 NOISE characteristics diagram 2 3 571 k 2 3 5 2 3 5 7100k Frequency Hz Figure 7 6 characteristics diagram M2177 7 4 7 2 Standard Data ELS gp 2 3 5 7 10k 2 3 5 7 100k 57100 23 5 3 2 5 7 10 N gt o E 5 LL IHF BPF characteristics diagram Figure 7 7 7 5 M2177 WABUN D 508556 3 If there are any misplaced or missing pages we will replace the manual Contact the sales representative NOTES e Reproduction of the contents of this manual is forbidden by applicable laws e The contents of this manu
3. _ _ _ 77 Note In the event that a breakdown or other abnormality has occurred in the M2177 check the following things first If you are still not able to clearly judge the source of the problem please submit a report of the symptoms and your check results This will help us provide the right kind of service and will make it easier for us to resolve the problem so your cooperation is kindly requested 1 The devices do not operate at all Is the power cord s input connector correctly plugged into an AC outlet Is there a blown fuse s the voltage setting correct 2 The meter s indicator goes off scale s excessive input being applied Is the input connected correctly Check for disconnection of signal cable on GND side etc Is oscillation occurring due to monitoring of the M2177 s AC output Does the meter s indicator go off scale even when the input is shorted 3 Indicated values are abnormal Is the sensitivity adjuster being used Is the UNCAL lamp ON s a weighting filter being used Is either the RESPONSE switch or the WEIGHT switch pressed but not both Has WEIGHT switch been pressed even though no optional parts have been attached s the input frequency within the specified range Is oscillation occurring due to monitoring the M2177 s output Are other ranges also abnormal Is the signal source s impedance too high 4 Range is not stable Is i
4. Contents Page 1 General Description dedo enia diente echten titt 1 12 essen er 1 1 3 1 1 4 Specifications 2 TAS Electrical ratings 2 14 2 Mechanical ratldas ue Ele einen 4 1 4 3 Installation requirements 4 Todd MOTIONS rita Ii lia 5 2 Preparations before Operation 2 1 22 OM PONTES sacan RICE ticis aen e Siit 2 1 2 9 TAASTAMA ESE 2 1 2 4 Power Supply and Grounding sss 2 2 3 Operations 3 1 Part Names and Functions x uni oe ia a 3 1 Ses WO GONNECHONS eiim ita EU MS 3 3 3 3 AA T 3 3 34 Gaulions Tor USO 3 3 4 Principles of Operation 41 Block SSS eM 4 1 5 Maintenance cm eu E ee 5 1 5 2 Operation GB A 5 1 5 3 Adjustment and Calibration sss 5 3 6 Easy Checks on Faulty Parts 7 Standard Data 7 1 Standard Dat a dt 7 1 Le Standard u ou un u uqunata dond 7 1 M2177 Figure 1 1 Figure 3 1 Figure 4 1 Figure 5 1 Figure 7 1 Figure 7 2 Figure 7 3 Figure 7 4 Figure 7 5 Figure 7 6 Figure 7 7 M2177 Figures Page External dimensions diagram 1 6 Diagrams of front and rear
5. AB313141 WA OY S TIMV GISV wince ae External dimensions diagram 4 Figure 1 1 6 M2177 M2177 2 Preparations before Operation 2 1 Combporients u T 2 1 Installation icc ect Heel hin 2 1 Power Supply and Grounding 2 2 2 1 Unpacking ELS 2 1 Unpacking After unpacking check for any damage that may have occurred during shipment Although all parts are carefully checked before shipment there may be loose components such as control knobs Also check the accessories against the component list shown in Table 2 1 Component List to make sure none are missing 2 2 Components The M2177 s standard components are listed in Table 2 1 Component List below Table 2 1 Component list Quantity Main unit 1 Instruction Manual 1 Accessories Power cord 3 prong 2 meter 1 Plug conversion adapter 1 Fuses 0 4 250 time lag 05 2 x 20 mm 1 Fuses are provided in fuse holder 2 3 Installation e Installation site Set the main unit so that the rubber feet on the bottom and the stand are on a smooth flat surface such as a desk or table e Install this product in an environment that meets the following ambient temperature and humidity requirements In operation 0 to 40 10 to 95 RH In storage 10 to 50 C
6. differential input or a similar means should be used so that common mode noise is not affected 3 3 3 4 Cautions for Use LLLLIL LLLZILILILLILLILLIocLLLELLAULIIuTC OGUL LELAAVISLIG GEGGIu GCT AGt AeTo Z V U ILANLAG OLSLUULIUU L OLB EDALIILLLI GAGLA ULULUqP BmUGGUGG UaLLELHIUA UUUGATGAdG GHHA AA GLU TG 5 Applying an excessive input will damage the M2177 The maximum non destructive input voltage is as follows 30 mV to 100 V range DC peak value 250 V 10 to 10 mV range 5 peak AC DC peak value 250 V In the 10 uV to 10 mV range application of an excessive input may reduce the input impedance to about 100 When the DC component s voltage is at least 5 V set the range to at least 30 mV before connecting an input and wait at least one second before setting the optimum range If the M2177 s built in protection circuit is activated and the PROTECT lamp lights up either disconnect the excessive input or switch it to a lower sensitivity range 6 The input terminals overvoltage category is category I AN WARNING Do not directly measure the voltage from a commercial power source such as a distribution panel or power outlet Electric shock may occur or the M2177 may be damaged by fire 7 After signals that include a DC component are measured a DC charge is applied to the input terminal This charge is retained even after the M2177 s power is turned off which poses a risk of
7. 10 to 85 This product should be used in a condensation free environment e Do not install this product in any of the following types of environments Anenvironment where flammable gas is present To avoid risk of explosion never install or use this product in an environment where flammable gas is present An outdoors site or other location that is exposed to direct sunlight or is close to a source of flame or heat This product may suffer degraded performance or operation faults in such environments M2177 2 1 2 4 Power Supply and Grounding HI QD n QQ V V DC RA A A A rDnmER i Anenvironment where corrosive gas or vapor dust or dirt is present or where the humidity is high Such environments can cause this product to corrode or break down A site close to a strong electromagnetic field source high voltage equipment or power transmission lines This product may suffer degraded performance or operation faults at such sites A high vibration environment This product may suffer operation faults or breakdowns in such an environment Also note that in some environments such as where pulsed noise is superimposed on signal lines the M2177 may have degraded performance Although the M2177 comes with a built in line filter an additional external line filter should be used in cases where not all noise is filtered out so that the M2177 can have power supply
8. mechanical zero point when using the dB linear scale the black mark at the left edge of the meter scale is the mechanical zero point Set RANGE to a low sensitivity level 100 V range Turn on the power via the power switch Let device unit warm up for at least 30 minutes Apply a signal and set the meter to a range between 1 3 full scale and 1 1 full scale Cautions for Use The M2177 is highly sensitive and its high input impedance is 1 MQ Consequently using a solid wire for the input cable or a wire with inadequate shielding will enable increased noise and may result in abnormal oscillation Although an oscilloscope probe can be used as an input cable noise will increase if the range is at or below 100 uV When a cable is connected to the AC output terminal induction occurs between the input cable and the AC output cable during high sensitivity mode which may increase the margin of error or cause oscillation In such cases increase the distance between the input cable and the AC output cable or add more extensive shielding When used as an amplifier When the meter s indicator goes off scale the output waveform may become distorted and abnormal oscillation may occur Also if the input is not sine wave input the meter output may be distorted even when the meter s indicator is not off scale When AC output or DC output is connected to another device When the M2177 s AC output or DC output is connected to an A D board
9. of this user s manual This user s manual contains information for the safe operation and use of this product Be sure to read this information first before using this product All the warnings in the user s manual must be heeded to prevent hazards that may cause major accidents Be sure to ground the product To prevent accidental electrocution always connect the M2177 to a grounding source rated as a Type 3 grounding source in the Technical Requirements for Electrical Appliances Use the supplied power cord 3 pin terminal to connect the M2177 to a power outlet with a three prong grounded contact If only two prong power outlets are available use a conversion adapter In such cases the conversion adapter s grounding wire should be attached to a nearby ground terminal before connecting the power cord to the outlet Check the power supply voltage This product operates on the power supply voltage indicated in 2 4 Power Supply and Grounding in this instruction manual Prior to connecting the power supply check that the voltage of the power supply matches the rated power supply of the product Observe the fuse ratings If not observed a fire may occur Use fuses with the ratings specified in 2 4 Power Supply and Grounding Be sure to disconnect the power cord from the outlet when replacing the fuses In case of suspected anomaly If this product emits smoke an abnormal smell or abnormal noise immediately power it o
10. technicians who are thoroughly acquainted with electrical safety principles and this product s structure Work where assistance is immediately available in case an accident occurs High voltage components in the internal power supply and on the circuit board pose a risk of electrocution if touched The following measuring instruments are required for adjustments and calibration AC standard voltage generator Frequency 400 Hz or 1 KHz Output voltage 1 Vrms 0 1 Digital voltmeter voltage measurement precision 0 1 when 1 V AC voltage measurement precision 0 2 400 Hz to 1 kHz 1 V Before starting operations close the M2177 s cover and let the M2177 warm up for at least one hour then quickly adjust and calibrate Once the warm up period has ended remove the protectors for the front and rear panels Remove the screws from the top and both sides then remove the top cover Figure 5 1 Marking drawing of PCB viewed from above with top cover removed shows the PCB as it appears from above after the top cover has been removed Make the following adjustments in the following order 1 ACOUT GAIN Set the M2177 to the 1 V range Set the AC standard voltage generator to 1 Vrms then connect it to the M2177 Connect a digital voltmeter to the AC output connector then measure the AC voltage Now adjust the 71 OUT GAIN so that the digital voltmeter s measured value is 1 V 0 2 2 DCOUT GAIN Set the M2177 to average
11. value detection AVE mode Connect a digital voltmeter to the DC output connector then measure the DC voltage Now adjust the 2 DC OUT GAIN so that the digital voltmeter s measured value is 1 V 0 1 3 Set the M2177 to root mean square detection RMS mode Adjust the 3 RMS GAIN so that the digital voltmeter s measured value is 1 V 0 1 4 Q PEAK GAIN Set the M2177 to quasi peak detection Q PEAK mode Adjust the 74 PEAK GAIN so that the digital voltmeter s measured value is 1 V 0 1 M2177 5 3 5 3 Adjustment and Calibration __ f 5 METER GAIN when dB linear option is not attached Set the M2177 to average detection AVE mode Adjust the S METER GAIN so that the digital voltmeter s measured value is 1 V 0 2 6 METER OFFSET when dB linear option is not attached Set the AC standard voltage generator to 300 mV then adjust the 6 METER OFFSET so that the meter s measured value is 300 mV 0 4 Steps 5 and 6 above can be repeated numerous times M2177 5 4 5 3 Adjustment and Calibration Y Rear side 5 METER GAIN 6 METER OFFSET 4 0 PEAK GAIN 2 DC QUT GAIN r W 20 3 RMS GAIN w a s e ur 1 AC OUT GAIN ous I A e e Es Front Figure 5 1 Marking drawing of PCB viewed from above with top cover removed M2177 5 5 6 Easy Checks on Faulty Parts M2177
12. 1 mV to 0 3 mV M2177 5 1 5 2 Operation Checks NY 57 2 Frequency characteristics check check the average value detection Measuring instrument Sine wave oscillator 5 Hz to 500 kHz Connect the oscillator with a terminating resistor and resistance attenuator conforming with the oscillator s output impedance Adjust the oscillator s voltage so that the meter is at full scale when at 1 kHz The meter is normal if it displays the following ranges Select an oscillator that keeps about 1 3 of the following frequency characteristics 30 range from 10 Hz to 30 kHz 5 from 5 Hz to 50 kHz 10 100 uV range from 10 Hz to 100 kHz 55 from 5 Hz to 250 kHz 10 300 to 100 V range from 20 Hz to 100 kHz 3 5 Hz to 500 kHz 10 3 Residual noise check Use a wire to short the M2177 s input connector then read the measured value The value is normal if it is within the following range the measured value may be to the left of the meter s zero point depending on the ambient temperature 30 range input equivalent noise is 5 uV or less average AVE detection mode is set When the dB linear scale option is attached the AC output measured by the AC voltmeter is 150 mV or less and the meter s measured value is to the left of the zero point when in the 30 uV range 4 Characteristics check of weighting filter Due to the filter s wide dynamic range it is not possible to check all frequency chara
13. AUTORANGING AC VOLTMETER NOISE METER M2177 INSTRUCTION MANUAL NF Corporation DA00010591 001 AUTORANGING AC VOLTMETER NOISE METER M2177 INSTRUCTION MANUAL 0000 WARRANTY 0000 NF Corporation certifies that this instrument was thoroughly tested and inspected and found to meet its published specifications when it was shipped from our factory All NF products are warranted against defects in materials and workmanship for a period of one year from the date of shipment During the warranty period of NF will at its option either will repair the defective product without any charge for the parts and labor or either repair or replace products which prove to be defective For repair service under warranty the product must be returned to a service center designated by NF Purchaser shall prepay all shipping cost duties and taxes for the product to NF from another country and NF shall pay shipping charge to returned the product to purchaser This warranty shall not apply to any defect failure or damage caused by improper use improper or inadequate maintenance and care or modified by purchaser or personnel other than NF representatives NF Corporation After sales service policy In the unlikely event that a breakdown or unidentified problem has occurred contact NF Corporation or an NF Corporation sales representative When contacting us please indicate the model name or product name manufacturer s serial number and a d
14. ailures check for sources of the problem and investigate fault locations 4 Troubleshooting This instruction manual describes only relatively simple methods for checking operations adjusting and calibrating this device and performing aging checks on faulty parts For more complicated checks calibrations or repairs contact an NF Corporation sales office or your local NF Corporation sales representative 5 2 Operation Checks First make sure the power is OFF then check the meter s zero point When the dB linear scale option is attached the black point on the left of the meter scale is the mechanical zero point The screw at the bottom center of the meter frame can be used to adjust the mechanical zero point Keep the SENSITIVITY knob set to the CAL position 1 Indication accuracy check The following measuring instruments are needed to check the accuracy of the meter s indicated values AC standard voltage generator Frequency 400 Hz or 1 kHz Output voltage 1 mV to 100 Vrms 0 1 Connect the generator to the M2177 and read the indicated values for each range while the meter is at full scale Indicated values are normal if their error margin is within 2 If this kind of generator is not available use an oscillator in combination with another calibrated AC voltmeter an accurate differential voltmeter or a digital voltmeter to check operations A calibrated resistance attenuator is used to check the range from 0 0
15. al may be revised without notice e Information provided in this manual is intended to be accurate and reliable However we assume no responsibility for any damage regarding the contents of this manual We assume no responsibility for influences resulting from the operations in this manual Copyright 2005 NF Corporation M2177 INSTRUCTION MANUAL NF Corporation 6 3 20 Tsunashima Higashi Kohoku ku Yokohama 223 8508 JAPAN Phone 81 45 545 8111 Fax 81 45 545 8191 http www nfcorp co jp NF Corporation 6 3 20 Tsunashima higashi Kohoku ku Yokohama 223 8508 JAPAN
16. cted to the power cord in order to prevent power problems and to ensure the safety of operators Ground the supplied power cord 3 pin terminal by connecting it to a power outlet that has a three prong grounded contact If only two prong power outlets are available use the bundled conversion adapter In such cases the conversion adapter s green grounding wire should be attached to a nearby ground terminal before plugging the power cord into the outlet M2177 2 3 M2177 3 1 3 2 3 3 3 4 3 Operations Part Names and Functions mate 3 1 VLO CONNECI NS sda descatutasedo 3 3 3 3 Gauti ns TOP USC uuu yaa u kiasa uuu a eee ee eus 3 3 3 1 Part Names and Functions 2 3 1 Part Names and Functions O Meters The voltage scale on the M2177 measurement meters are from 0 to 3 5 and 0 to 11 and the decibel scales are from 16 to 3 dBm and from 20 to 1 When the dB linear scale option is attached the decibel scale is a linear scale with ranges from 10 to 3 dBm and 13 to 1 dBV and its voltage scales are from 0 7 to 3 5 and 2 2 to 11 The lamp at the top of the meter indicates the current measuring range 1 3 full scale 1 3 full scale Mechanical zero point Normal scale Scale using dB linear scale option POWER Power switch This is the power control switch When this switch is pressed its lamp lights up to indicate that the M2177 is in operation ready m
17. cteristics Connect a resistance attenuator between the oscillator and M2177 then check in the reference level 10 dB range The oscillator s frequency should be set to 0 1 accuracy For description of the characteristic curve see 7 Standard Data If the measured value at O dB point frequency on the characteristic curve is the same 0 5 dB as when the 6 WEIGHT switch is set to FLAT the reference level is normal Table 5 1 Reference levels of standard equipped weighting filters JIS A 500Hz 3 2dB JIS C 500Hz OdB DIN AUDIO 1kHz OdB CCIR ARM 6 3kHz 6 6dB b Auto ranging function Input 1kHz sine wave and set the 1 V range and average detection AVE mode Next gradually increase the input voltage The range is normal if it goes up to between 1 02 full scale and 1 08 full scale Next gradually decrease the input voltage The range is normal if it goes down to between 0 22 full scale and 0 26 full scale When the input is shorted the range is lowered and it is normal if it stops at 30 uV range M2177 5 2 5 3 Adjustment and Calibration EM 5 3 Adjustment and Calibration 5 2 Operation Checks described adjustment and calibration that can be performed only with semi fixed resistors when rated values are not met Never touch any parts other than the specified adjustment sites AN WARNING All maintenance and adjustment of this product should be performed only by service
18. e wave Switchable The quasi peak detection complies with the DIN and CCIR standards except when 1 4 full scale or below e Tolerable crest factor 5 at full scale input RMS detection e Meter Includes mirror and taut band Voltmeter scales Oto 11 0 to 3 5 Decibel scales 20 to 1 dBV 16 to 3 dBm 0 dBm 1 mW 6000 Note There is no scale for values less than 0 1 of full scale e AC output Output connector BNC R Output impedance 500 Typ recommended load impedance at least 5 Output voltage 1 V with full scale input and no load Output voltage accuracy Same as accuracy meter s average detection mode Maximum output voltage 10 Vpeak 1 kHz no load and linear operation Maximum output current 10 mA linear operation M2177 1 3 1 4 Specifications gt e DOC output Output connector BNC R Output impedance 50 recommended load impedance at least 5 Output voltage 1 V with full scale input no load Output voltage accuracy Same as accuracy meter s average detection mode Maximum output current 10 mA Typ linear operation Ripple 0 14 Vp p Typ with no load full scale input average detection and 10 Hz e Autorange function 20 Hz to 500 kHz AUTO Auto switching of ranges for input signals below approximately 2 4 or above 10 5 on the 11 level full scale HOLD This stops the auto range switching function When the range knob is turned the range is switched upwa
19. electric shock when discharge occurs A WARNING Input should be shorted for at least one second after measuring a signal with a large DC component 8 The VO terminal GND side is connected to the frame via 100 connection This is to prevent inaccurate measurements when the device has been installed in a rack or is otherwise in contact with another device s frame AN CAUTION Never apply voltage of 1 V or more between the I O terminal s GND side and the frame M2177 3 4 3 4 Cautions for Use E A 9 Cautions for use of weighting filter An amplifier is connected in front of the weighting filter Figure 4 1 Diagrams of front and rear panels Although there is no problem for the dynamic range as far as the filter s input when measuring noise in a part such as the audio amplifier if for example a signal comprised of frequencies exceeding 100 kHz is read in the vicinity of the full scale of the meter the signal may be saturated inside the device To determine this set the WEIGHT switch to the FLAT setting and use an oscilloscope to observe the AC output If the waveform becomes saturated it may cause measurement errors to occur when using a weighting filter However when measuring white noise in either average value detection mode or RMS detection mode slight saturation is of very short duration and thus has almost no effect on measured values Although the M2177 s dynamic range is approximately 26 dB when t
20. en gradually increase the sensitivity M2177 3 1 3 1 Part Names and Functions lt WEIGHT Weighting filter This switch is used to set the weighting filter Up to six weighting filters can be included which provides seven settings including FLAT filter name is shown on any switch that does not have a corresponding filter When the FLAT button is pressed this device becomes an ordinary wide frequency range AC voltmeter RESPONSE Detection method switches Press AVE to set average detection Press RMS to set true root mean square detection Press to set quasi peak detection These detection methods comply with the DIN and CCIR standards except when at or below 1 4 full scale VOLTAGE SELECTOR 2 4 Power Supply and Grounding AC OUTPUT AC output terminal The AC output terminal is used whenever this voltmeter is used as a waveform monitor or amplifier The output voltage is 1 V during full scale mode and the output impedance is 50QTyp recommended load impedance at least 5 kQ DC OUTPUT DC output terminal The DC output terminal is used to record measured values via a recorder The output voltage is 1 V at the meter s full scale Ripple increases as the measuring frequency is reduced If problems occur connect a resistor and electrolytic capacitor as in the example shown in the figure However this will slow the DC output respo
21. etailed description of the problem and the use conditions under which it occurred Although we do our best to repair products as promptly as possible repair of products older than five years may be delayed by difficulties in obtaining replacement parts Note that in cases where replacement parts are no longer being manufactured repairs may be declined if the product in question has extensive damage or has been substantially modified M2177 i Preface Thank you for purchasing the M2177 Autoranging AC Voltmeter Noise meter Be sure to read the section entitled Safety Precautions in advance to ensure safe use of this electrical product B Caution Symbols Used in This Manual The following caution symbols are used in this manual Be sure to observe these caution symbols and their contents to ensure the safety of the user and avoid damage to the equipment AN WARNING This mark indicates information for the avoidance of a hazard such as electric shock that may endanger human life or cause injury during handling of the equipment N CAUTION This mark indicates information for the avoidance of damage to the equipment during handling M2177 ii Safety Precautions To ensure safe use be sure to observe the following warnings and cautions NF Corporation shall not be held liable for damages that arise from a failure to observe these warnings and cautions M2177 Be sure to observe the contents
22. ff and stop using it If such an anomaly occurs do not use this product until it has been repaired and immediately report the problem to the location of purchase either NF Corporation or your distributor Do not use this product when gas is present Do not use this product when gas is present as this may cause an explosion Do not remove the cover This product contains high voltage parts Absolutely never remove its cover Even when the inside of this product needs to be inspected do not touch the inside All such inspections are to be performed by service technicians designated by NF Corporation M2177 Do not modify this product Use only parts designated by NF Corporation as replacement parts Use of non designated parts may result in new hazards or may interfere with repairs when breakdowns occur Safety related symbols The general definitions of the safety related symbols used on this product and in the instruction manual are provided below AN Instruction Manual Reference Symbol This symbol is displayed to alert the user to potential danger and refer him her to the instruction manual AN WARNING Warning Symbol Together with this symbol information is provided in order to prevent users from encountering hazards such as electric shock that could result in serious injury or death AN CAUTION Caution Symbol This symbol indicates information for preventing damage to the product when handling it iv
23. he SENSITIVITY control is used to lower the sensitivity note with caution that the dynamic range will be narrowed proportionately Since the weighting filter has a wide dynamic range of several dozen decibels the filter s amplitude characteristics cannot be measured via the M2177 s meter or DC output 10 When measuring a frequency at or below 20 Hz the range may not be stable if the signal line has high impedance 50 or above or quasi peak detection mode Q PEAK has been selected In such cases use HOLD mode instead 11 The M2177 s RMS detection method measures only the RMS voltage values of AC components M2177 Consequently when measuring signals that have superposed DC components use the following formula to calculate the RMS voltage that includes DC components E AC DC rms 4 E sc oos E pc 3 5 3 4 Cautions for Use Front panel ww SR 82177 h AUTORAMONNC VULTT TER Rear panel VOLTAGE SELECTOR yA 1 173 gt 1533 u Figure 3 1 Diagrams of front and rear panels M2177 3 6 4 Principles of Operation 4 1 Block Diagram Pre eee a 4 1 M2177 4 1 Block Diagram EM 4 1 Block Diagram Input is applied to ATTI and its DC component is blocked by capacitor C When using high sensitivity range of 100 or less insert a low pass filter for ATT2 to limit the bandwidth according to the range SENSITIVITY is a variab
24. input free of pulsed noise components Do not install the power cord near an input cable 2 4 Power Supply and Grounding 1 Power supply The M2177 operates under the following power supply requirements e 100 120 230 Vrms 10 AC power controlled via power switch on rear panel 50 60 Hz 25 VA or less Fuses 0 4 A 250 V time lag 5 2 20 mm Overvoltage category CAT The power cord bundled as a standard accessory which has a voltage rating of 125 V AC and a dielectric withstand voltage of 1250 V for one minute is intended for use in Japan only The power cord must be changed to enable use outside of Japan or at a voltage higher than 125 V AC For information please contact NF Corporation AN CAUTION The power supply voltage setting is factory set at 100 V AC Please confirm this setting AN WARNING e Always remove the power plug from the outlet before changing the power supply voltage setting or replacing a fuse Set the power supply voltage control switch correctly to one of the three possible voltage setting positions Note that the 120 V setting position has about 2 mm of loose positioning above and below Check the power supply voltage control switch s setting before turning on the power e Use only fuses that have the specified capacity M2177 2 2 2 4 Power Supply and Grounding 2 Grounding AN WARNING Always ground this product using a grounding line conne
25. le resistor which can be used to vary the meter s sensitivity in a range from 0 to 10 dB Two weighting filters WEIGHT can be added see option 1 and option 2 in Figure 4 1 Block diagram CCIR ARM can be changed to another filter if specified when ordering The DETECTOR block uses a full wave rectifier circuit that includes an operational amplifier The RMS detector uses a squaring circuit in a semiconductor The AUTORANGING LOGIC block is used to adjust ATT1 and ATT2 according to the DC signal output of the DETECTOR in order to set the optimum range When using the dB linear scale option LOG AMP is inserted between DETECTOR and the meter In such cases the DC output is logarithmic ATTI PREAMP ATT2 SENSITIVITY WEIGHT DRIVE AMP AC OUT AMP FLAT AUS Figure 4 1 Block diagram M2177 4 1 5 Maintenance 5 1 OUTING setae eet eta ii ias 5 1 5 2 Operation Checks seccion 5 1 5 3 Adjustment and Calibration 5 3 M2177 5 1 Outline 5 1 Proper maintenance is required to keep this device optimum condition Normally such maintenance includes the following four steps 1 Operational check Make sure the device operates correctly according to the rated values 2 Adjustment and calibration If the device is not operating correctly adjust or calibrate the specified parts 3 Detecting fault locations If there are f
26. nse speed When the dB linear scale option is attached the output may become negative in which case a nonpolarized electrolytic capacitor should be used Also when the dB linear scale option is attached the DC output becomes logarithmic output The meter scale becomes 1 V when at 0 dBV or 0 V when at 10 dBV i e 0 1 V dB 10k 52 w To DC output wou 2 To recorder LINE 50 60 Hz Use this connector to connect the power cord Make sure the power cord plug is fully inserted so it will not come loose easily A fuse holder is located below this connector The cap on the fuse holder can be removed with a flat head screwdriver after the power cable has been removed 2 4 Power Supply and Grounding M2177 3 2 3 2 3 2 Connections Y Connections Connect the signal cable to the input terminal If a reduced input capacity is desired use a shorter line to connect the M2177 to the object to be measured via the shortest possible distance When using this voltmeter as a waveform monitor or amplifier connect an oscilloscope or similar device to the AC output terminal When using a recorder to record data connect it to the DC output terminal 3 3 Startup The M2177 operates via the following sequence 1 59 DA E 3 4 1 2 3 4 2177 Make sure the power switch is correctly set for the power supply voltage to be used Plug in the power cord Check the meter s
27. ode SENSITIVITY Sensitivity adjuster This adjuster is able to alter the meter s sensitivity in 10 dB increments When the dial is turned completely clockwise the value that was set with RANGE will become the meter sensitivity When the dial is turned counterclockwise until the UNCAL lamp lights up the sensitivity is reduced and this may prevent direct readouts in which case relative values must be read This sensitivity adjuster is used for S N and or decibel measurements INPUT Input terminal This is a receptacle that is used to connect input signals Its input impedance is 1 and its parallel capacity is 25 pF or less If the M2177 s internal protection circuits are activated and the PROTECT lamp lights up disconnect any excessive input and or switch to a lower sensitivity range O RANGE Sensitivity switching When the HOLD AUTO button on the right is pressed the range becomes fixed in HOLD mode When the pressed button is released to its previous position AUTO mode is set and the optimum range is set automatically When the range is fixed in HOLD mode turning the UP DOWN knob on the left side clockwise sets a higher sensitivity range and turning it counterclockwise sets a lower sensitivity range Even when in AUTO mode if the measured value is near the edge of the meter s scale this UPDOWN knob can be turned to set the optimum range When measuring an unknown voltage start in the 100 V range and th
28. rd or downward one range at a time e Power supply 100V 120V 230V AC 10 50 60 Hz 25 VAmax Overvoltage category CAT II 1 4 2 Mechanical ratings e Dimensions 140 W 177 H 300 D mm not including protruding parts e Weight 3 5 kg Typ 1 43 Installation requirements e Ambient temperature and humidity In operation 0 C to 40 C 10 to 95 RH no condensation In storage 10 C to 50 10 to 85 RH no condensation e Contamination level 2 M2177 1 4 1 4 Specifications AD 1 4 44 Options e Filters options when ordering used for weighting etc Two filters can be added three can be added if CCIR ARM is removed The CCIR ARM can also be changed to CCIR DIN 45405 Noise gt 2 Either CCIR or CCIR ARM can be selected but not both 1 3 oct band pass filter The following frequencies in the 10 Hz to 20 kHz range 10 12 5 16 20 25 31 5 40 50 63 80 Example fo 100 Hz 315 Hz 800 Hz 1 kHz e dB linear scale option when ordering Voltage scales 2 2 to 11 0 7 to 3 5 Decibel scales 13 to 1 10 to 3 dBm 0 dBm 1 mW 600 Q DC output voltage 1 V with full scale input no load 0 V with 10 dB of full scale input no load M2177 1 5 1 4 Specifications JFeued 149402 eued Buisseooud eoeung sud 220 DO B wm
29. re RMS detection 30 uV range 5 from 20 Hz to 30 kHz 10 from 5 Hz to 50 kHz 100 to 100 V range 3 from 20 Hz to 100 kHz 10 from 5 Hz to 250 kHz Average AVE detection 30 uV range 2596 from 10 Hz to 30 kHz 21095 from 5 Hz to 50 kHz 100 uV range 2596 from 10 Hz to 100 kHz 21090 from 5 Hz to 250 kHz 300 uV to 100 V rang 2396 from 20 Hz to 100 kHz X596 from 7 Hz to 200 kHz 21090 from 5 Hz to 500 kHz Quasi peak Q PEAK detection 30 uV range 2596 from 20 Hz to 10 kHz 220906 from 5 Hz to 30 kHz 100 uV to 100 V range 2596 from 20 Hz to 10 kHz 21095 from 10 Hz to 30 kHz 22090 from 5 Hz to 100 kHz 1 2 1 4 Specifications r A e Inputs Input connector BNC R Input impedance 1 25 pF or less Non destructive maximum input voltage 30 mV to 100 V range Peak value of AC DC 250 V 30 uV to 10 mV range AC 5 V peak peak value of AC DC 250 V Overvoltage category CAT 1 e Sensitivity adjustment range 0 to 10 dB or more e Weighting filters JIS A JIS C1502 JIS C JIS C1502 DIN 45405 AUDIO and CCIR ARM are included Two additional filters can be added three can be added if CCIR ARM is removed The CCIR ARM can also be changed to CCIR e Measurement methods True root mean square RMS detection Average detection and root mean square indication calibrated by sine wave Quasi peak detection calibrated by sin
30. t stable during HOLD mode Does the measured signal include any low frequency components Is the signal source s impedance too high M2177 6 1 7 Standard Data 7 1 On Standard Data iterato cad 7 1 1 2 Standard Data eee id 7 1 M2177 7 1 On Standard Data ELS 7 1 On Standard Data The standard data described below has been recorded for the M2177 s weighting filter characteristics At NF Corporation this standard data is used as a reference when attempting to minimize variation in performance as one of the company s guality control technigues When this data is measured for a product s various performance features the average measured value should be this standard value In some cases the M2177 s characteristics fall short of the standard data but users can rest assured that the results of strict testing are used to check for full compliance with rated values before products are shipped 7 2 Standard Data Figure 7 1 JIS C1502 JIS A characteristics diagram nennen 7 2 Figure 7 2 JIS C1502 JIS C characteristics dia gram sendet 7 2 Figure 7 3 CCIR ARM characteristics did 7 3 Figure 7 4 DIN 45405 AUDIO characteristics diagram n 7 3 Figure 7 5 DIN 45405 NOISE characteristics diagram n 7 4 Figure 7 6 CCIR characteristics diagram rn mn en Bu 7 4 Figure 7 7 characteristics diagram nennen 7 5 M2177 7 1 7 2 Standard Data
31. tion 0 to 10 dB e Meter includes mirror for easier legibility e linear scale is available as an option 1 3 Applications e Large meters are used to facilitate in line inspections e The sensitivity adjuster can be used to measure S N ratios e This product can also be used as a signal conditioner variable gain preamplifier e This product can be used as an attenuator for input up to 250 Vpeak For sine waves it can be used as a sensitivity adjuster for up to 176 Vrms e Voltage variation data can be recorded by connecting a recorder or A D board to this product s DC output terminals M2177 1 1 1 4 Specifications 1 4 1 4 1 M2177 Specifications Electrical ratings Measurement range Voltage measurement range 30 u Vrms full scale CD to 100 Vrms full scale 1 3 series 14 ranges 1 Full scale is defined as level 10 on a meter with an 11 level scale Frequency range True root mean square RMS detection 30 uV range 5 Hz to 50 kHz 100 pV to 100 V range 5 Hz to 250 kHz Average AVE detection 30 uV range 100 uV range 5 Hz to 50 kHz 5 Hz to 250 kHz 300 uV to 100 V range 5 Hz to 500 kHz Quasi peak Q PEAK detection 30 uV range 5 Hz to 30 kHz 100 to 100 V range 5 Hz to 100 kHz Meter measurement accuracy 23 C 5 C 1 5 full scale or above CAL Percentage vs full scale is shown True root mean squa
32. utoranging AC Voltmeter Noise Meter is a full scale AC voltmeter that features an autoranging function Four types of weighting filters are standard equipped and two additional filters can be added as options The detection mode can be switched among root mean square detection RMS average value detection AVE and quasi peak detection Q PEAK modes so the M2177 can also be used as a noise meter The M2177 includes an AC output terminal that enables it to be used as a signal conditioner The M2177s input impedance is typically 1 MQ and it can be connected to the probe of various commercial oscilloscopes Since the M2177 also includes a DC output terminal it can be used as an AC DC converter with measurement values saved to a recorder Specification when ordering the M2177 Additional weighting filters can be specified gt 1 4 4 Options 5 linear scale option is available to make the decibel scale an evenly incremented scale 1 2 Features e High seed auto range switching Approximately 100 ms per range e High sensitivity 30 full scale e Switchable display modes Display modes are root mean square detection average detection or quasi peak detection e Weighting filters Four types JIS A JIS C DIN 45405 AUDIO and CCIR ARM are included Up to two more types of weighting filters can be added as built in options Includes AC and DC output terminals Includes sensitivity adjustment func
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