Autoranging True RMS Multimeter TM-87 / TM
Contents
1. Fig 8 Using the instrument for Capacitance measurement bh Selecting the position 2 Insert the test leads into the jacks the red plug into HzVQuA jack and black plug into COM jack see Fig 8 3 Connect the red and black test clamps to the capacitor terminals respecting if necessary the proper polarities The capacitance value is shown on display 4 Pressing the R SEL key to select the correct range or using the Autorange feature see paragraph 4 2 4 If the capacitance value under test is unknown select the highest range 5 Ifthe message O L is displayed the maximum readable value is reached 6 For HOLD function Minimum and Maximum value measurement and Relative measure please refer to paragraph 4 2 15 TM 87 TM 88 4 3 8 Frequency measurement bh CAUTION The maximum input for AC voltage is 750Vrms Do not attempt to measure higher voltages to avoid electrical shocks or damages to the instrument TENMARS TM 87 Fig 9 Using the instrument for Frequency measurement Selecting the position Hz Insert the test leads into the jacks the red plug into HzVQuA jack and black plug into COM jack see Fig 9 Connect the test leads to the circuit under test The frequency value will be displayed Pressing the R SEL key to select the correct range or using the Autorange feature see paragraph 4 2 4 If the freqency value under test is unknown select the highest range If the message O L is displayed t2. TM 87 TM 88 4 3 MEASUREMENTS 4 3 1 DC Voltage measurement CAUTION The maximum input for DC voltage is 1000V Do not attempt to measure higher voltages to avoid electrical shocks or damages to the instrument MAL CATH HoF i EU E puien gt L A i i A il 1 COM ei d Fig 2 Using the meter for DC Voltage measurement 1 Selecting the position V 2 Pressing the R SEL key to select the correct range or using the Autorange feature see paragraph 4 2 4 If the voltage value under test is unknown select the highest range 3 Insert the test leads into the jacks the red plug into HzVQuA jack and black plug into COM jack see Fig 2 4 Connect the red and black test leads to the positive and negative poles of the circuit under test respectively The voltage value is displayed 5 If the message O L is displayed select a higher range 6 Ihe symbol on the instrument display indicates that voltage has opposite direction with regard to the connection 7 For HOLD function Minimum and Maximum value measurement and Relative measure please refer to paragraph 4 2 i TM 87 TM 88 4 3 2 AC Voltage measurement CAUTION The maximum input for AC voltage is 750Vrms Do not attempt to measure higher voltages to avoid electrical shocks or damages to the instrument Fig 3 Using the instrument for AC Voltage measurement 1 Selecting the position Va 2 Pressing the R SEL key to select the correct ran
3. 3 8 Frequency measurement sessssssssssesseseeeeee nennen nnne renun sa ananas esas nnne sn nns 16 4 3 9 Temperature test Only for TMS 17 5 MAINTENANCE E 18 51 General Ino dure ME 18 ma Balon OD ACS MN ui iii ii aida 18 5 3 FUSO TEDIACSMEM Dusan OO DO A 19 s ee Un ee ee ee aaa 19 5 5 End oiite nenne nnnsenennenn 19 6 TECHNICAL SPECIFICATIONS EE 20 Oe EECa AUS a 20 6 1 1 Electrical specifications E 22 AA 22 SA He E CN 23 6 2 Ie MMIC INN EE 23 6 2 1 Environmental conditions 23 622 EMS By RE 23 BI ACCESO MES epo vba qnse ope RN MN EMINENS 23 6 3 1 Standard ACCC SONOS user Puta ERE SU A 23 A re sE E OH Oe 24 7 1 Warranty Conditions 24 Pita Aller SA EE 24 TM 87 TM 88 1 TM 87 TM 88 SAFETY PRECAUTIONS AND PROCEDURES This meter is in compliance with safety Standards EN 61010 1 related to electronic measuring instruments For your own safety and to avoid damaging the instrument follow the procedures described in this instruction manual and read carefully all notes preceded by this symbol N When taking measurements Avoid doing that in humid or wet places make sure that humidity is within the limits indicated in paragraph 6 2 1 Avoid doing that in rooms where explosive gas combustible gas steam or excessive dust is present Keep you insulated from the object under test Do not touch exposed metal parts such as test lead ends sockets fixing objects circuits etc Avoid doing that if you
4. manufacturer will not be responsible for any damage to persons or things The warranty doesn t apply to e Accessories and batteries not covered by warranty e Repairs made necessary by improper use including adaptation to particular applications not provided in the instructions manual or improper combination with incompatible accessories or equipment e Repairs made necessary by improper shipping material causing damages in transit e Repairs made necessary by previous attempts for repair carried out by unskilled or unauthorized personnel e Instruments for whatever reason modified by the customer himself without explicit authorization of our Technical Dept The contents of this manual may not be reproduced in any form whatsoever without the manufacturer s authorization Our products are patented and our logotypes registered We reserve the right to modify specifications and prices in view of technological improvements or developments which might be necessary 7 2 AFTER SALE SERVICE Shouldn t the instrument work properly before contacting your distributor make sure that batteries are correctly installed and working check the test leads and replace them if necessary Make sure that your operating procedure corresponds to the one described in this manual Should you need for any reason to return back the instrument for repair or replacement take prior agreements with the local distributor from whom you bought it Do not forget
5. the installation make sure that the rotary selector is positioned on the right function Make sure that LCD and rotary selector indicate the same function 2 TM 87 TM 88 1 2 DURING USE CAUTION An improper use may damage the instrument and or its components or injure the operator e When changing the range first disconnect the test leads from the circuit under test in order to avoid any accident e When the instrument is connected to measuring circuits never touch any unused terminal e When measuring resistors do not add any voltage Although there is a protection circuit excessive voltage could cause malfunctioning e f during measurement the displayed values remain constant check whether the HOLD function is active 1 3 AFTER USE e After using the instrument turn it off e f you expect not to use the instrument for a long period remove the battery to avoid leakages of battery liquids which may damage its inner components 1 4 MEASURING OVERVOLTAGE CATEGORIES DEFINITIONS EN 61010 1 Safety requirements for electrical equipment for measurement control and laboratory use Part 1 General requirements gives a definition of measuring category usually called overvoltage category Paragraph 6 7 4 Measuring circuits OMISSIS circuits are divided into the following measurement categories e Measurement category IV is for measurements performed at the source of the low voltage installation Examples are electrici
6. the technical specifications contained in this manual and such compliance is guaranteed for 1 year Annual recalibration is recommended 3 4 STORAGE After a period of storage under extreme environmental conditions exceeding the limits mentioned in paragraph 6 2 1 let the instrument resume normal measuring conditions before using it 4 OPERATING INSTRUCTIONS 4 1 INSTRUMENT DESCRIPTION 4 1 1 Front panel o i e on o o o E E o amp 9 b amp TM 87 TM 88 LEGEND L LCD 2 HOLDKey 3 PK REL Key 4 MV MNKey 5 R SEL Key Backlight YY Key OFF position DCV position ACV position 10 Posizione Q 1l St position 12 position 13 Hz position 14 ADC position C and F position TIV 88 15 AAC position DCuA and ACUA position TIM 88 16 DCAand ACA position 17 COMAand VK uA C F vo NA Fig 1 Instrument description TM 87 TM 88 4 2 DESCRIPTION OF FUNCTION KEYS When pressing a key the corresponding symbol is displayed with a beep To resume default state turn the selector on another function 4 2 1 HOLD key By pressing HOLD key the measured value is frozen on the display where the symbol HOLD appears Press again HOLD to disable this function and resume normal operation 4 2 2 PK REL key This key have the double function of measuring max min peak values active for V and uA positions of rotary selector and performing relative measurements REL for V A Hz
7. ACrms 400 0MHz 0 1MHz Not declared Minimum pulse duration 25ns 30 lt Duty Cycle lt 70 Capacitance Overload protection 4 000nF 0 001nF 40 00nF 0 01nF Not declared 400 0nF 4 000uF 0 001uF o 40 004 F 0 01 n 2 0 rdg 8dgt 600Vrms 4 000mF 000mF x 001 et A 40 00mF LO 0 ordg 20dat Temperature 40 C 0 C 1 8 rdg 3 C 1 C 400 C 1 0 rdg 3 C Max input voltage for 401 C 800 C 2 0 rdg 3 C thermocouple DC60V AC24V 40 F 32 F 1 8 rdg 5 F 33 F 778 F 1 0 rdg 5 F 779 F 1382 F 2 0 rdg 5 F The tolerance of temp probe excluded 21 TM 87 TM 88 6 1 1 Electrical specifications Conversion TRMS Measuring rate 1 5 times per second Temperature coefficient 0 15x accuracy C lt 18 C and gt 28 C NMRR Normal Mode Rejection Ratio gt 50dB for DC parameters and 50 60Hz CMRR Common Mode Rejection Ratio gt 100dB from DC up to 60Hz on DCV gt 60dB from DC up to 60Hz on ACV 6 1 2 Safety The instrument complies to EN 61010 1 Insulation Class 2 Double insulation Pollution degree 2 Overvoltage category CAT IV 600V CAT III 1000V V Q uA Max height 2000m 22 TM 87 TM 88 6 1 3 General data Mechanical characteristics Dimensions 163 L x 88 W x 48 H mm Weight including batteries approx 400g Power supply Battery type 1 x 9V battery NEDA1604 JISOO6P IEC6F22 Indication of low batteries the symbol is displayed when batteri
8. Autoranging True RMS Multimeter TM 87 TM 88 User s manual Cor Cau 4 gt de Trms 2 gt e Hz uA A rer _ _CATHI 1000V FUSED A vn i HB2 T M8700000 Contents 1 SAFELY PRECAUTIONS AND PROCEDURES ees s eia ee eei er Exp ee 2 US PEE c uas 2 j E BOIS U e eo oo E o oil O 3 E AUST SS eses 3 1 4 Measuring overvoltage categories definitions ooonccccnnncccccnncccconncnncnnnncnnnnnncnnnns 3 2 GENERAL DESCRIPTION 4 2 1 Mean value and TRMS detmton nnne 4 2 2 True root mean square value and crest factor deimmton 4 2 ce le EN POR Oe one eer 5 IL A A 5 9 2 ele Ae Ee erret rimo bote rbbEo rer niire EE Rete hdd ede iiien irienn reinir Eniri 5 PECES ele tee MT UU 5 3 4 Storage eee 5 d ORERATINGINS TRUC HONG aca ine 6 4 1 Instrument description nenne nenne nenne nenne nenne nenn nnnnn nenn nnnnn nnns 6 Alls cendo NEN 6 42 DOSCHDHIOD OL TUMCION EE 7 4 2 1 HOLD key 7 4 2 2 PK REL key 7 EC E GER 7 A A o 7 4 2 5 Backlight key Ki 8 4 2 6 Disable Auto Power Ott 8 do TE un CC 9 4 3 1 DC Voltage measurement nennen nennen nnne nn nnn nnns nana nnns 9 ee Ee ee En En E 10 4 3 3 DC Current measurement nenne nenne nenn nenne nnn rn nnn nenne nennen 11 4 3 4 AC Current measurement nenne anne nnns nnn sns ener nennen 12 4 3 5 Resistance measurement and Continuity Test 13 4 36 IOS TO Nm 14 4 3 7 Capacitance measurement nn nennen 15 4
9. Q St and uA positions of rotary selector This key have the double function of measuring max min peak values active for V and uA positions of rotary selector and performing relative measurements REL for V Hz Q gt gt and C F positions of rotary selector TM 88 Press cyclically PK REL to measure and save peak values Pmax and Pmin symbols on the display correspond to Maximum Peak and Minimum Peak values respectively which are continuously updated by the meter By keeping pressed PK REL key for at least 3 seconds CAL symbol appears on the display and the meter performs an auto calibration permitting a higher accuracy on peak measurements To exit this function keep pressed PK REL for at least one second or rotate the selector on another position By pressing PK REL key the relative measurement is activated the meter saves the offset value on the display and the REL symbol is shown The following measurement will be referred to this offset value By pressing again PK REL key the offset value is shown and the REL symbol is blinking To exit this function keep pressed PK REL for at least one second or rotate the selector on another position 4 2 3 MX MN key By pressing MX MN key maximum and minimum values are measured Both values are stored and automatically updated as soon as an higher value MAX or lower value MIN are measured by meter The symbol corresponding to the desired function i
10. e replaced LEGEND Disconnect the test leads from the input terminals Remove the fixing screws from the back case and detach it Remove the battery replacing it with new one 9V NEDA1604 JIS006P IEC6F22 respecting the polarity signs and replace the back case and screws Use the appropriate battery disposal methods for your area Fig 10 Battery replacement 18 TM 87 TM 88 5 3 FUSE REPLACEMENT CAUTION Before replacing fuses disconnect test leads from any energized circuit to avoid electrical shock x A LEGEND A O 1 Turn OFF the meter and AAA Dees disconnect the test leads from the IEG UL MER y input terminals sn 2 Unscrew the four fixing screws of in cg AE the back holster and remove it DA eas 3 Remove the defective fuse and Af Lhe m I ID install a new fuse of the same size fa c D Sy 4 and rating fast 10A 1000V wa oe DE Bussmann type Make sure the D ses Z n new fuse is centered in the fuse gt POE yn holder Re screw the back holster Lo Fig 11 Fuse replacement 5 4 CLEANING To clean the instrument use a soft dry cloth Never use a wet cloth solvents or water 5 5 END OF LIFE Caution this symbol indicates that equipment and its accessories shall be subject to a separate collection and correct disposal NENNEN 19 TM 87 TM 88 6 TECHNICAL SPECIFICATIONS 6 1 TECHNICAL FEATURES The accuracy is indicated as of reading number o
11. es are low Battery life approx 300 hours Auto power OFF after 30 minutes Display opecifications 4 LCD with max reading 3999 counts symbol decimal point sign and bargraph Out of range indications OL or OL 6 2 ENVIRONMENT 6 2 1 Environmental conditions Reference temperature 23 5 C Working temperature 0 30 C Relative humidity lt 80 HR Storage temperature 20 60 C Storage humidity lt 80 HR 6 2 2 EMC and LVD This meter is designed and tested in compliance to the requirements of the European EMC Directive 89 336 EEC modified with 93 68 CEE and in accordance to Low Voltage Directive 73 23 EEC 6 3 ACCESSORIES 6 3 1 Standard accessories The package contains e Pair of test leads e User s manual e Battery e Carrying Case 23 TM 87 TM 88 7 SERVICE 7 1 WARRANTY CONDITIONS This instrument is guaranteed against material or production defects in accordance with Our general sales conditions During the warranty period the manufacturer reserves the right to decide either to repair or replace the product Should you need for any reason to return back the instrument for repair or replacement take prior agreements with the local distributor from whom you bought it Do not forget to enclose a report describing the reasons for returning detected fault Use only original packaging Any damage occurred in transit due to no original packaging will be charged anyhow to the customer The
12. f digits at 23 C 5 C lt 80 HR DC Voltage l Overload 400 0mV 0 5 rdg 3dgt 4 000V 0 001V 40 00V 0 01V 0 5 rdg 2dgt 10MQ lt 100pF SE 400 0V 1000V 1 0 rdg 2dgt AC TRMS Voltage Range Resolution ER Input impedance Overload 9 50 500Hz Pe protection 400 0mV Not declared 1 3 rdg 5dgt 4 000V 0 001V 50 300HZ 1000VDC 40 00V 0 01V IDN 100pF 750VACrms 1 5 rdg 3dgt 400 0V 50 500H2 750V DC Current Overload 400 0uA lt 5mV uA 750Vrms 4000uA 1uA 1 0 rdg 2dgt 10 00A 0 01A Fuse 10A 1000V AC TRMS Current Accuracy Overload 40004A 1 5 rdg 5dat 50 399Hz 2 0 rdg 5dat 400 500Hz 10 004 Fuse 10A 1000V Resistance Range Resolution Accurac Max Open Overload a i Circuit Voltage protection 400 00 1 0 rdg 5dgt about 13V 4 000kQ 0 001kQ 40 00kQ 0 01kQ 0 8 rdg 2dgt 600Vrme 400 0kQ 0 1kQ about 0 45V 4 000M O 0 001MQ 1 0 rdg 2dgt 40 00MQ 0 01MO 1 5 rdg 5dgt 20 ge gen e TM 87 TM 88 Diode Test Resolution meculacy Test Open Overload 0 4 0 8V current Er protection ME 10mV 1 5 rdg 5dgt 60Vms Continuity Test Feature Buzzer Open voltage Overload protection about 1 3V 600Vrms Frequency Sensitivity Overload protection 4 000kHz 0 001kHz gt 1 5VACrms BEE Za 0 1 rdg 2dgt une l Z l 0 1 rag 20g 4 000MHz 0 001MHz aries SEIN 40 00MHz 0 01MHz 5V
13. ge or using the Autorange feature see paragraph 4 2 4 If the voltage value under test is unknown select the highest range 3 Insert the test leads into the jacks the red plug into HzVQuA jack and black plug into COM jack see Fig 3 4 Connect the test leads to the circuit under test The voltage value is displayed If the message O L is displayed select a higher range For HOLD function Minimum and Maximum value measurement and Peak measurement please refer to paragraph 4 2 D o 10 TM 87 TM 88 4 3 3 DC Current measurement CAUTION The maximum input for DC current is 10A Do not attempt to measure higher currents to avoid electrical shocks or damages to the instrument TENMARS TM 87 Fig 4 Using the instrument for DC Current measurement bh Power off the circuit under test Lt es 77 2 Selecting the position Ar The message is shown at display 3 Insert the test leads into the jacks the red plug into A jack and black plug into COM jack see Fig 4 4 Connect the red and the black plugs in series with the circuit whose current is to be measured respecting the polarities 5 Energize the circuit under test The current value will be displayed 6 The message O L means that the detected current exceeds the limits 7 f the measured value is lower than 4mA to get a better resolution e Switch off the circuit under test e urn the selector on uA e Remove the red test lead from A jac
14. he maximum readable value is reached For HOLD function Minimum and Maximum value measurement and Helative measure please refer to paragraph 4 2 16 a TM 87 TM 88 4 3 9 test uM for TM 88 The maximum input of AC voltage is 24Vrms DC voltage is 60V Do not N attempt to measure higher voltages to avoid electrical shocks or damages to the instrument HOLD rege une Be O grt Trms MAX CAT 1000V 104 nv T EET A Fig 10 Using the instrument for Temperature test 1 Selecting the position C F 2 Pressing the R SEL key to select the C and F readinos 3 Insert the banana plug adapter 110 with correct plug into Wa HZuA C jack and plug into COM jack with banana pins to K type socket to adapt other standard K type mini plug temperature probes 4 Connect the other ends of temperature test leads for temperature measurement 17 5 MAINTENANCE 5 1 GENERAL INFORMATION TM 87 TM 88 This is a precision instrument To guarantee its performances be sure to use it according to these instructions and keep it stored on suitable environmental conditions Do not expose it to high temperatures or humidity or direct sunlight Be sure to turn it off after use If you expect not to use the instrument for a long period remove batteries to avoid leakages of battery liquid which could damage its inner components 5 2 BATTERY REPLACEMENT When the low battery indication ig shown the battery it s to b
15. hich would be dispersed in the same period of time by a direct current having an intensity of 1A From this definition comes the numerical to T expression G g Gd The effective value is indicated as RMS root mean square The Crest Factor is defined as the ratio between the Peak Value of a signal and its effective value CF G 2 This value varies according to the waveform of the signal RMS for a purely sinusoidal wave it s worth 42 1 41 In presence of distortions the Crest Factor assumes higher values as long as the wave distortion is higher TM 87 TM 88 3 PREPARATION FOR USE 3 1 INITIAL This instrument was checked both mechanically and electrically prior to shipment All possible cares and precautions were taken to let you receive the instrument in perfect conditions Notwithstanding we suggest you to check it rapidly eventual damages may have occurred during transport if so please contact the local distributor from whom you bought the item Make sure that all standard accessories mentioned in paragraph 6 3 1 are included Should you have to return back the instrument for any reason please follow the instructions mentioned in paragraph 7 3 2 SUPPLY VOLTAGE The instrument is supplied by 1x9V battery type NEDA1604 JISOO6P IEC6F22 When battery is low a low battery indication is displayed To replace insert battery please refer to paragraph 5 2 3 3 CALIBRATION The instrument complies with
16. k and insert it into HzVQuA jack and power the circuit under test Press R SEL key if necessary to select an higher range 8 The symbol on the instrument display indicates that current has opposite direction with regard to the connection 9 For HOLD function Minimum and Maximum value measurement and Relative measure please refer to paragraph 4 2 11 TM 87 TM 88 4 3 4 AC Current measurement CAUTION The maximum input for DC current is 10A Do not attempt to measure higher currents to avoid electrical shocks or damages to the instrument U Tenmars TM 87 zZ Fig 5 Using the instrument for AC Current measurement Power off the circuit under test 2 Selecting the position A By pressing R SEL key to select AC measurement The v symbol is shown at display 3 Insert the test leads into the jacks the red plug into A jack and black plug into COM jack see Fig 5 4 Connect the red and the black plugs in series with the circuit whose current is to be measured 5 Energize the circuit under test The current value will be displayed 6 The message O L means that the detected current exceeds the limits 7 f the measured value is lower than 4mA to get a better resolution e Switch off the circuit under test e urn the selector on uA e Remove the red test lead from A jack and insert it into HzVQuA jack and power the circuit under test Press R SEL key if necessary to select an higher range 8 F
17. notice anomalous conditions such as breakages deformations fractures leakages of battery liquid blind display etc Be particularly careful when measuring voltages exceeding 20V to avoid risk of electrical shocks The following symbols are used 1 1 2 al e gt CAUTION refer to the instruction manual an improper use may damage the instrument or its components Danger high voltage risk of electric shocks Double insulated meter AC voltage or current DC voltage or current PRELIMINARY This instrument has been designed for use in environments of pollution degree 2 lt can be used for VOLTAGE and CURRENT measurements on installations of overvoltage CAT III 1000V and CAT IV 600V This instrument is not suitable for measurements of non sine wave voltage and current When using the instrument always respect the usual safety regulations aimed at protecting you against the dangerous electric currents and protecting the instrument against incorrect operations Only the leads supplied with the instrument guarantee compliance with the safety Standards in force They must be in good conditions and if necessary replaced with identical ones Do not test or connect to any circuit exceeding the specified overload protection Do not effect measurements under environmental conditions exceeding the limits indicated in paragraphs 6 1 1 and 6 2 1 Make sure that batteries are properly installed Before connecting the test probes to
18. o RENE CH r ido i 600 AL Fig 7 Using the instrument for Diode test Selecting the position PF 2 Insert the test leads into the jacks the red plug into HzVQuA jack and black plug into COM jack 3 Connect the test leads to the diode under test observing the proper polarities see Fig 7 The threshold voltage value of direct polarization is shown at display The meter displays the diode voltage to approximately 0 4 0 9V for good junction 4 f the threshold voltage value is OV the diode P N junction is shorted circuit 5 f the message O L is displayed the diode terminals are reversed or the diode P N junction is damaged 6 For HOLD function Minimum and Maximum value measurement and Relative measure please refer to paragraph 4 2 14 TM 87 TM 88 4 3 7 Capacitance measurement CAUTION Before taking capacitance measurements in circuit remove power from the circuit being tested and discharge all capacitors Use the short test lead pair for measurement to reduce the stray capacitance Before connecting the test capacitor observe the display which may have a reading other than zero every time the range is changed Subtract this offset reading from the displayed reading of the test result of a capacitor to obtain the true value Connect the test capacitor to the inputs respecting the polarity connections when required Due to internal delay time bargraph it s no operative in Capacitance measurement
19. or HOLD function Minimum and Maximum value measurement Peak measurement for NuA position and for Relative measurement for A position please refer to paragraph 4 2 12 TM 87 TM 88 4 3 5 Resistance measurement and Continuity Test CAUTION Before taking resistance measurements on the circuit remove power from the circuit being tested and discharge all capacitors oC war E Fig 6 Using the instrument for Resistance measurement and Continuity test Selecting the position Q 2 Insert the test leads into the jack the red plug into HzVQuA jack and black plug into COM jack see Fig 6 3 Connect the test leads to the circuit under test The resistance value is displayed 4 Pressing the R SEL key to select the correct range or using the Autorange feature see paragraph 4 2 4 If the resistance value under test is unknown select the highest range 5 If the message O L is displayed a higher range must be selected 6 The continuity test is always active and the test is performed using the test leads in the same way of resistance measurement The buzzer is on for resistance values lt 35Q 7 For HOLD function Minimum and Maximum value measurement and Relative measure please refer to paragraph 4 2 13 TM 87 TM 88 4 3 6 Diode test CAUTION Before taking diode test on remove power from the circuit being tested and discharge all capacitors TENMARS TM 87 y A DM E A s Trms L
20. rgraph is also available The selected quantity is displayed with indication of measuring unit and active functions The instrument disposes of an Auto Power Off function consisting in an automatic switching off 30 minutes after last selector rotation or function selection 2 1 MEAN VALUE AND TRMS DEFINITION Safety testers for AC quantities are divided in two big families e MEAN VALUE instruments measuring only the value of the wave at the fundamental frequency 50 or 60 Hz e TRUE ROOT MEAN SQUARE or TRMS instruments measuring the true root mean square value of the quantity under test In presence of a perfectly sinusoidal wave both families provide identical results While in presence of distorted waves readings are different Mean value instruments provide only the value of the fundamental wave while TRMS instruments provide the value of the entire wave including harmonics within the passband of the instrument Accordingly if the same quantity is measured with both kinds of instruments the measured values are identical only if the wave is purely sinusoidal Should it be distorted TRMS instruments provide higher values than MEAN VALUE instruments 2 2 TRUE ROOT MEAN SQUARE VALUE AND CREST FACTOR DEFINITION The effective current value is defined as follows In an interval of time equivalent to a period an alternate current with effective value having an intensity of 1A by passing ona resistor disperses the same energy w
21. s displayed MAX for maximum value MIN for minimum value MX MN key is disabled when HOLD function is active To exit this function keep MX MN key pressed for at least 1 second or rotate the selector to another position 4 2 4 R SEL key By pressing R SEL key the manual selection of measured range exception A and A positions and the selection of a double function which are included on selector by choosing between Q measure and AC or DC Current are possible The MANU symbol is shown at display by pressing R SEL key and the cyclically pressure of the key change the measuring range and fix the decimal point on the display Press R SEL key at least 1second or rotate the selector to exit from this function and restore the AUTO symbol at display TM 87 TM 88 4 2 5 Backlight key Y By pressing key it s possible to activate the backlight function on the display The function automatically disabled itself after some seconds and is available on each position of the rotary selector 4 2 6 Disable Auto Power OFF When the meter is to be used for long periods of time the operator might want to disable the AutoPowerOFF function Once the AutoPowerOFF function is disabled the meter stays on continuously To disable the AutoPowerOFF function e Switch OFF the meter e Turn ON the meter keeping pressed PK REL MX MIN and R SEL keys The AutoPowerOFF function is automatically activated when turning ON again the meter
22. to enclose a report describing the reasons for returning detected fault Use only original packaging Any damage occurred in transit due to non original packaging will be charged anyhow to the customer The manufacturer will not be responsible for any damage to persons or things 24 1
23. ty meters and measurements on primary overcurrent protection devices and ripple control units e Measurement category Ill is for measurements performed in the building installation Examples are measurements on distribution boards circuit breakers wiring including cables bus bars junction boxes switches socket outlets in the fixed installation and equipment for industrial use and some other equipment for example stationary motors with permanent connection to fixed installation e Measurement category ll is for measurements performed on circuits directly connected to the low voltage installation Examples are measurements on household appliances portable tools and similar equipment e Measurement category l is for measurements performed on circuits not directly connected to MAINS Examples are measurements on circuits not derived from MAINS and specially protected internal MAINS derived circuits In the latter case transient stresses are variable for that reason the norm requires that the transient withstand capability of the equipment is made known to the user 3 u TM 87 TM 88 2 GENERAL DESCRIPTION This meter performs the below listed measurements DC and AC TRMS Voltage DC and AC TRMS Current Resistance and Continuity test Frequency Capacitance Diode test All selectable by means of a 10 position rotary selector including OFF position Functions keys are also available see chapter 4 2 An analogical ba
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