User`s Guide Digital Multimeter Extech 420
Contents
1. Function Range Resolution Accuracy Frequency 5 000Hz 0 001Hz 1 5 reading 5 digits 50 00Hz 0 01Hz 500 0Hz 0 1Hz a Mig 1 2 reading 2 digits 50 00kHz 0 01kHz 500 0kHz 0 1kHz PONE ee 1 5 reading 4 digits 10 00MHz 0 01MHz Sensitivity 0 8V rms min 20 to 80 duty cycle and lt 100kHz 5Vrms min 20 to 80 duty cycle and gt 100kHz Duty Cycle 0 1 to 99 9 0 1 1 2 reading 2 digits Pulse width 100us 100ms Frequency 5Hz to 150kHz Temp 20 to 750 C 1 C 3 0 reading 3 digits type K 4 to 1382 F 1 F probe accuracy not included NOTE Accuracy specifications consist of two elements e reading This is the accuracy of the measurement circuit e digits This is the accuracy of the analog to digital converter Diode Test Continuity Check Temperature Sensor Input Impedance AC Response ACV Bandwidth Display Overrange indication Auto Power Off Polarity Measurement Rate Low Battery Indication Battery Fuses Operating Temperature Storage Temperature Operating Humidity Storage Humidity Operating Altitude Weight Size Safety Test current of 0 3mA maximum open circuit voltage 1 5V DC typical Audible signal will sound if the resistance is less than 1500 approx test current lt 0 7mA Requires type K thermocouple gt 7 5MQ VDC amp VAC Average responding 50Hz to 1kHz 4000 count backlit liquid crystal OL is displayed 15 minutes approximately2. 5 ALWAYS discharge filter capacitors in power supplies and disconnect the power when making resistance or diode tests 6 ALWAYS turn off the power and disconnect the test leads before opening the covers to replace the fuse or battery 7T NEVER operate the meter unless the back cover and the battery and fuse covers are in place and fastened securely 4 EX420 en GB v3 4 4 15 Controls and Jacks CON OY CN c 9 10 11 4000 count LCD display HOLD SELECT button Function switch mA UA and A input jacks COM input jack Positive input jack RANGE hold button RELATIVE button Backlight button Protective holster Note Tilt stand and battery compartment are on rear of unit Symbols and Annunciators Continuity Diode test Battery status Test lead connection error nano 10 capacitance micro 105 amps cap milli 10 volts amps A Amps kilo 10 ohms F Farads capacitance mega 10 ohms Q Ohms Hertz frequency V Volts Percent duty ratio REL Relative Alternating current AUTO Autoranging Direct current HOLD Display hold Degrees Fahrenheit C Degrees Centigrade AUTO IR ya HOLD m uid mun DOOD EX420 en GB v3 4 4 15 Operating Instructions WARNING Risk of electrocution High voltage circuits both AC and DC are very dangerous and should be measured with great care 1 ALWAYS turn the function switch to the OFF position when t
3. Automatic no indication for positive Minus sign for negative 2 times per second nominal s B is displayed if battery voltage drops below operating voltage One 9 volt NEDA 1604 battery mA HA ranges 0 5A 250V fast blow A range 20A 250V ceramic fast blow 5 C to 40 C 41 F to 104 F 20 C to 60 C 4 F to 140 F Max 80 up to 31 C 87 F decreasing linearly to 50 at 40 C 104 F lt 80 2000 meters 7000ft maximum 342g 0 753Ib includes holster 187 x 81 x 50mm 7 36 x 3 2 x 2 0 includes holster For indoor use and in accordance with the requirements for double insulation to IEC1010 1 2001 EN61010 1 2001 Overvoltage Category IIl 600V and Category II 1000V Pollution Degree 2 13 EX420 en GB v3 4 4 15 Maintenance WARNING To avoid electrical shock disconnect the meter from any circuit remove the test leads from the input terminals and turn OFF the meter before opening the case Do not operate the meter with an open case This MultiMeter is designed to provide years of dependable service if the following care instructions are performed 1 KEEP THE METER DRY If it gets wet wipe it off 2 USE AND STORE THE METER IN NORMAL TEMPERATURES Temperature extremes can shorten the life of the electronic parts and distort or melt plastic parts 3 HANDLE THE METER GENTLY AND CAREFULLY Dropping it can damage the electronic parts or the case 4 KEEP THE METER CLEA
4. point where you wish to measure current 7 Touch the black test probe tip to the negative side of the circuit Touch the red test probe tip to the positive side of the circuit 8 Apply power to the circuit 9 Read the current in the display 7 EX420 en GB v3 4 4 15 AC CURRENT MEASUREMENTS CAUTION Do not make current measurements on the 20A scale for longer than 30 seconds Exceeding 30 seconds may cause damage to the meter and or the test leads 1 Insert the black test lead banana plug into the negative COM jack 2 For current measurements up to 4000pA AC set the function switch to the yellow pA position and insert the red test lead banana plug into the uA mA jack 3 For current measurements up to 400mA AC set the function Switch to the yellow mA position and insert the red test lead banana plug into the pA mA jack 4 For current measurements up to 20A AC set the function switch to the yellow 20A range and insert the red test lead banana plug into the 20A jack 5 Press the SELECT button to indicate AC on the display 6 Remove power from the circuit under test then open up the circuit at the point where you wish to measure current 7 Touch the black test probe tip to the negative side of the circuit Touch the red test probe tip to the positive side of the circuit 8 Apply power to the circuit 9 Read the current in the display RESISTANCE MEASUREMENTS WARNING To avoid electric shock disconnect power
5. test probes to the diode under test Forward voltage will Set the function switch to the green 3j position typically indicate 0 400 to 0 700V Reverse voltage will indicate OL Shorted devices will indicate near OV and an open device will indicate OL in both polarities CAPACITANCE MEASUREMENTS WARNING To avoid electric shock disconnect power to the unit under test and discharge all capacitors before taking any capacitance measurements Remove the batteries and unplug the line cords Set the rotary function switch to the green 4r position Insert the black test lead banana plug into the negative COM jack Insert the red test lead banana plug into the positive jack Touch the test leads to the capacitor to be tested Read the capacitance value in the display 9 EX420 en GB v3 4 4 15 FREQUENCY MEASUREMENTS i 2 3 4 DUTY CYCLE 1 2 3 4 5 Set the rotary function switch to the green Hz position Insert the black lead banana plug into the negative COM jack and the red test lead banana plug into the positive Hz jack Touch the test probe tips to the circuit under test Read the frequency on the display Set the rotary function switch to the Hz position Insert the black lead banana plug into the negative COM jack and the red test lead banana plug into the positive Hz jack Press the SELECT key momentarily to select in the display Touch the test probe tips
6. 14 EX420 en GB_v3 4 4 15 REPLACING THE FUSES WARNING To avoid electrical shock disconnect the meter from any circuit remove the test leads from the input terminals and turn OFF the meter before opening the case Do not operate the meter with an open case 8 9 A Disconnect the test leads from the meter Remove the protective rubber holster Remove the battery cover two B screws and the battery Remove the four A screws securing the rear cover Lift the center circuit board straight up from the connectors to gain access to the fuse holders Gently remove the old fuse and install the new fuse into the holder Always use a fuse of the proper size and value 0 5A 250V fast blow for the 400mA range 20A 250V fast blow for the 20A range Align the center board with the connectors and gently press into place Replace and secure the rear cover battery and battery cover WARNING To avoid electric shock do not operate your meter until the fuse cover is in place and fastened securely Copyright 2013 2015 FLIR Systems Inc All rights reserved including the right of reproduction in whole or in part in any form 1SO 9001 Certified www extech com 15 EX420 en GB_v3 4 4 15
7. EXTECH User s Guide INSTRUMENTS Digital Multimeter Extech 420 Introduction Congratulations on your purchase of the Extech 420 part number EX420 Autoranging Multimeter This meter measures AC DC Voltage AC DC Current Resistance Capacitance Frequency Duty Cycle Diode Test and Continuity plus Thermocouple Temperature Proper use and care of this meter will provide many years of reliable service Safety International Safety Symbols This symbol adjacent to another symbol or terminal indicates the user must refer to the manual for further information This symbol adjacent to a terminal indicates that under normal use hazardous voltages may be present Double insulation gp This WARNING symbol indicates a potentially hazardous situation which if not avoided could result in death or serious injury CAUTION This CAUTION symbol indicates a potentially hazardous situation which if not avoided may result damage to the product MAX This symbol advises the user that the terminal s so marked must not be 600V connected to a circuit point at which the voltage with respect to earth ground exceeds in this case 600 VAC or VDC Ad 2 EX420 en GB_v3 4 4 15 CAUTIONS e Improper use of this meter can cause damage shock injury or death Read and understand this user manual before operating the meter e Always remove the test leads before replacing the battery or fuses e Inspect the condition of the
8. N Wipe the case occasionally with a damp cloth DO NOT use chemicals cleaning solvents or detergents 5 USE ONLY FRESH BATTERIES OF THE RECOMMENDED SIZE AND TYPE Remove old or weak batteries so they do not leak and damage the unit 6 IF THE METER IS TO BE STORED FOR A LONG PERIOD OF TIME the batteries should be removed to prevent damage to the unit Battery Replacement 1 Remove the Phillips head screw that secures the rear battery door 2 Open the battery compartment 3 Replace the 9V battery 4 Secure the battery compartment Never dispose of used batteries or rechargeable batteries in household waste As consumers users are legally required to take used batteries to appropriate collection sites the retail store where the batteries were purchased or wherever batteries are sold l Disposal Do not dispose of this instrument in household waste The user is obligated to take end of life devices to a designated collection point for the disposal of electrical and electronic equipment Other Battery Safety Reminders o Never dispose of batteries in a fire Batteries may explode or leak o Never mix battery types Always install new batteries of the same type WARNING To avoid electric shock do not operate the meter until the battery cover is in place and fastened securely NOTE If your meter does not work properly check the fuses and batteries to make sure that they are still good and that they are properly inserted
9. asurements relative to a stored reference value A reference voltage current etc can be stored and measurements made in comparison to that value The displayed value is the difference between the reference value and the measured value 1 Perform the measurement as described in the operating instructions Press the REL button to store the reading in the display and the REL indicator will appear on the display 3 The display will now indicate the difference between the stored value and the measured value 4 Press the REL button to exit the relative mode Note The Relative function does not operate in the Frequency function DISPLAY BACKLIGHT Press the 3 key for to turn on or off the display backlight function HOLD The hold function freezes the reading in the display Press the HOLD key momentarily to activate or to exit the hold function AUTO POWER OFF The auto off feature will turn the meter off after 15 minutes LOW BATTERY INDICATION The amp icon will appear in the lower left conner of the display when the battery voltage becomes low Replace the battery when this appears WRONG CONNECTION INDICATION The 3 icon will appear in the upper right conner of the display and the buzzer will sound whenever the positive test lead is inserted into the 20A or uA mA input jack and a non current green black or red function is selected If this occurs turn the meter off and reinsert the test lead into the proper input jack for the f
10. at no voltage is present CAUTION Do not measure AC voltages if a motor on the circuit is being switched ON or OFF Large voltage surges may occur that can damage the meter Set the function switch to the green V position 2 Press the SELECT button to indicate AC on the display 3 Insert the black test lead banana plug into the negative COM jack Insert red test lead banana plug into the positive V jack 4 Touch the black test probe tip to the neutral side of the circuit Touch the red test probe tip to the hot side of the circuit 5 Read the voltage in the display DC CURRENT MEASUREMENTS CAUTION Do not make current measurements on the 20A scale for longer than 30 seconds Exceeding 30 seconds may cause damage to the meter and or the test leads 1 Insert the black test lead banana plug into the negative COM jack 2 For current measurements up to 4000pA DC set the function switch to the yellow pA position and insert the red test lead banana plug into the uA mA jack 3 For current measurements up to 400mA DC set the function Switch to the yellow mA position and insert the red test lead banana plug into the pA mA jack 4 For current measurements up to 20A DC set the function switch to the yellow 20A range and insert the red test lead banana plug into the 20A jack 5 Press the SELECT button to indicate DC on the display 6 Remove power from the circuit under test then open up the circuit at the
11. he meter is not in use 2 If OL appears in the display during a measurement the value exceeds the range you have selected Change to a higher range NOTE On some low AC and DC voltage ranges with the test leads not connected to a device the display may show a random changing reading This is normal and is caused by the high input sensitivity The reading will stabilize and give a proper measurement when connected to a circuit DC VOLTAGE MEASUREMENTS CAUTION Do not measure DC voltages if a motor on the circuit is being switched ON or OFF Large voltage surges may occur that can damage the meter 1 Set the function switch to the green V position 2 Press the SELECT button to indicate DC on the display 3 Insert the black test lead banana plug into the negative COM jack Insert the red test lead banana plug into the positive V jack 4 Touch the black test probe tip to the negative side of the circuit Touch the red test probe tip to the positive side of the circuit 5 Read the voltage in the display 6 EX420 en GB v3 4 4 15 AC VOLTAGE MEASUREMENTS WARNING Risk of Electrocution The probe tips may not be long enough to contact the live parts inside some 240V outlets for appliances because the contacts are recessed deep in the outlets As a result the reading may show 0 volts when the outlet actually has voltage on it Make sure the probe tips are touching the metal contacts inside the outlet before assuming th
12. t with the skin Always therefore use suitable hand gloves in such cases e See that the batteries are not short circuited Do not throw batteries into the fire 3 EX420 en GB_v3 4 4 15 OVERVOLTAGE CATEGORY III This meter meets the IEC 610 1 2001 standard for OVERVOLTAGE CATEGORY III Cat III meters are protected against overvoltage transients in fixed installation at the distribution level Examples include switches in the fixed installation and some equipment for industrial use with permanent connection to the fixed installation SAFETY INSTRUCTIONS This meter has been designed for safe use but must be operated with caution The rules listed below must be carefully followed for safe operation 1 NEVER apply voltage or current to the meter that exceeds the specified maximum Input Protection Limits Function Maximum Input V DC or V AC 1000V DC 750V AC 200Vrms on 400mV range mA AC DC 500mA 250V fast acting fuse AACIDC 20A 250V fast acting fuse 30 seconds max every 15 minutes Frequency Resistance Capacitance 250Vrms for 15sec max Duty Cycle Diode Test Continuity Temperature 60V DC 24V AC 2 USEEXTREME CAUTION when working with high voltages 3 DO NOT measure voltage if the voltage on the COM input jack exceeds 600V above earth ground 4 NEVER connect the meter leads across a voltage source while the function switch is in the current resistance or diode mode Doing so can damage the meter
13. test leads and the meter itself for any damage before operating the meter Repair or replace any damage before use e Use great care when making measurements if the voltages are greater than 25VAC rms or 35VDC These voltages are considered a shock hazard e Warning This is a class A equipment This equipment can cause interferences in the living quarters in this case the operator can be required to carry out adequate measures e Always discharge capacitors and remove power from the device under test before performing Diode Resistance or Continuity tests e Voltage checks on electrical outlets can be difficult and misleading because of the uncertainty of connection to the recessed electrical contacts Other means should be used to ensure that the terminals are not live e Ifthe equipment is used in a manner not specified by the manufacturer the protection provided by the equipment may be impaired e This device is not a toy and must not reach children s hands It contains hazardous objects as well as small parts that the children could swallow In case a child swallows any of them please contact a physician immediately e Donotleave batteries and packing material lying around unattended they can be dangerous for children if they use them as toys e Incase the device is going to be unused for an extended period of time remove the batteries to prevent them from training e Expired or damaged batteries can cause cauterization on contac
14. to the circuit under test Read the duty cycle on the display CONTACT TEMPERATURE MEASUREMENTS 1 2 3 4 Note The temperature probe is fitted with a type K mini connector A mini connector to Set the function switch to the black Type K C or F position Insert the Temperature Probe into the input jacks making sure to observe the correct polarity Touch the Temperature Probe head to the part whose temperature you wish to measure Keep the probe touching the part under test until the reading stabilizes about 30 seconds Read the temperature in the display banana connector adaptor is supplied for connection to the input banana jacks 10 EX420 en GB_v3 4 4 15 AUTORANGING MANUAL RANGE SELECTION When the meter is first turned on it automatically goes into AutoRanging This automatically selects the best range for the measurements being made and is generally the best mode for most measurements For measurement situations requiring that a range be manually selected perform the following 1 Press the RANGE key The AUTO display indicator will turn off 2 Press the RANGE key to step through the available ranges until you select the range you want 3 To exit the Manual Ranging mode and return to AutoRanging press and hold the RANGE key for 2 seconds Note Manual ranging does not apply for the Capacitance Frequency and Temperature functions RELATIVE MODE The relative measurement feature allows you to make me
15. to the unit under test and discharge all capacitors before taking any resistance measurements Remove the batteries and unplug the line cords 1 Set the function switch to the green Q position 2 Insert the black test lead banana plug into the negative COM jack Insert the red test lead banana plug into the positive jack 3 Press the SELECT button to indicate O on the display 4 Touch the test probe tips across the circuit or part under test It is best to disconnect one side of the part under test so the rest of the circuit will not interfere with the resistance reading 5 Read the resistance in the display 8 EX420 en GB v3 4 4 15 CONTINUITY CHECK WARNING To avoid electric shock never measure continuity on circuits or wires that have voltage on them 1 2 Insert the black lead banana plug into the negative COM jack Insert the red test lead banana plug into the positive Q jack 3 Press the SELECT button to indicate on the display 4 Touch the test probe tips to the circuit or wire you wish to check 5 If the resistance is less than approximately 1500 the audible signal will sound If the circuit is open the display will indicate OL DIODE TEST 1 Set the function switch to the green j position 2 Insert the black test lead banana plug into the negative COM jack and the red test lead banana plug into the positive diode jack 3 Press the SELECT button to indicate on the display 4 Touch the
16. unction selected 11 EX420 en GB v3 4 4 15 Specifications Function Range Resolution Accuracy DC Voltage 400mV 0 1mV 0 3 reading 2 digits 4V 0 001V 40V 0 01V 0 5 reading 2 digits 400V 0 1V 1000V 1V 0 8 reading 3 digits AC Voltage 50 to 400Hz 400Hz to 1kHz 400mV 0 1mV 1 5 reading 15 2 5 reading 15digits digits 4V 0 001V 40V 0 01V d 6 42 59 reading 8 digits 400V 0 1V ae 750V 1V 1 8 reading 6 3 reading 8 digits digits DC Current 400uA 0 1uA SUDO TER 1 5 reading 3 digits 40mA 0 01mA 400mA 0 1mA i ON 2 5 reading 5 digits 20A 0 01A AC Current 50 to 400Hz 400Hz to 1KHz 400A 0 1uA AA GT mA B5 a 8 3 096 reading 7 digits 400mA 0 1mA 4A 0 001A 3 0 reading 8 3 5 reading 10 20A 0 01A digits digits Resistance 400Q 0 10 0 8 reading 4 digits 4kQ 0 001kQ 0 8 reading 2 digits 40kQ 0 01kQ 400kQ 0 1kQ 1 0 reading 2 digits 4MQ 0 001MQ 40MQ 0 01MQ 3 0 reading 5 digits Capacitance 40nF 0 01nF 5 0 reading 7 digits 400nF 0 1nF 3 0 reading 5 digits 4uF 0 001 nF 3 5 reading 5 digits 40uF 0 01uF 100uF 0 1uF 5 0 reading 5 digits NOTE Accuracy is stated at 18 C to 28 C 65 F to 83 F and less than 75 RH 12 EX420 en GB_v3 4 4 15
Download Pdf Manuals
Related Search