DIGITAL MULTIMETER 1. Introduction Thank you for buying the. This digital multimeter has a large LCD, a data-hold function and a backlight. The device uses a very practical safety mechanism that keeps the user from connecting measuring leads to the wrong jacks It is ideal for use in open air, workshops and schools and for home and hobby applications. 2. Safety The meter complies with the standards IEC-1010-1, CAT.II 1000V and CAT. III 600V overvoltage. Respect the following safety instructions to ensure maximum personal safety and to keep the device itself in good working order : Protect yourself against electroshocks. Do not use this device for any other application than those described in this manual. Do not use the device around explosive gases, vapour or dust. Disconnect the circuit you wish to test and discharge all capacitors before measuring resistance, continuity, diodes or capacity. Measure a known voltage to verify the meter's operation. Have the device serviced if the measurement of that known voltage doesn't yield the expected result. Connect the black test lead with the COM jack first and then connect the red test lead with the jack of your choice; always disconnect the red test lead and then the black one. For current measurements you should check the meter's fuse and turn off the power to the circuit under test before connecting the meter to the circuit. This device comes with a number of safety mechanisms: a varistor protects the Ω and V connection against transients > 1000V. A PTC resistor protects the device against overvoltages up to 1000V during resistance, capacity, temperature, continuity and diode measurements. This meter's VΩ, µa/ma and A connections are protected against the faulty connection of test leads. The jacks that can't be used for the selected function are closed off. The selector closes off all jacks that cannot be used with the function currently selected. The selector is blocked when it encounters a function that is incompatible with the selected jack. Remove the red test lead first and install a new range or function. Make sure the device was not damaged in transit. Make sure the insulation of the test leads is not damaged and/or the wire itself is not exposed. Full compliance with safety standards can only be guaranteed if the device is used with the supplied test leads. If necessary, they should be replaced with identical leads or leads with identical electric ratings. All test leads should be in good working order. Never exceed the specified limit values for the various measurement ranges. Do not touch unused terminals when the meter is connected to a circuit. Place the range selector switch in the highest position if the value to be measured is unknown beforehand. Do not measure voltages > 1000V above earth ground in Cat. II installations or 600V in Cat. III installations. The REL symbol is displayed when the relative mode is activated. Beware of dangerous voltages. Exercise extreme caution when working with voltages in excess of 60VDC or 30Vrms AC. Keep your fingers behind the probe barriers while using the device. Do not connect the leads to a voltage source while the function switch is in one of the following modes : current, resistance, capacitance, inductance, temperature, frequency, diode, transistor or continuity. Disconnect all test leads from the circuit to be tested prior to selecting a different function or range. When performing measurements on TV's or switching power circuits, the user should keep in mind that voltage surges may occur at test points. These surges may damage the meter. 1
Never perform resistance and continuity measurements on live circuits. Never perform capacitance measurements unless the capacitor in question has been fully discharged. Have the device checked by a qualified technician in case of malfunction. Never use the meter if the back panel is not in place and firmly fixed. Do not use or store the device in areas exposed to direct sunlight, high temperatures or high humidity. 2.1. Symbols Important safety information, consult the manual! Double insulation DC (direct current) AC or DC (alternating current or direct current) Earth ground Fuse Low battery AC (alternating current) 2.2 Maintenance Do not remove the back cover while a voltage is being applied. Only a qualified technician can handle repairs. Always disconnect the test leads from all current sources before opening the meter. Replace the three AAA batteries when the symbol is displayed. Replace blown fuses with an identical one or a fuse with identical voltage and current ratings : F 200mA/250V (quick-acting, max. resistance 2Ω), F 10A/250V ( quick-acting ). Use a damp cloth and a mild detergent to clean the device. Never apply abrasives or solvents. Place the power switch in the OFF position when the device is not being used Remove the batteries to keep them from leaking if the device is to be stored for a prolonged period of time. 3. Front Panel Description 1. LCD display 2. Keypad 3. Rotary switch 4. Terminals 5. Battery cover 2
4. LCD Description Number Symbol Explanation 1 Low-battery indicator 2 - Indicates negative readings 3 Indicator for AC voltage and AC current 4 Indicator for DC voltage and DC current 5 AUTO Autorange indicator 6 Indicator for diode test mode 7 Indicator for continuity check 8 DATA-H Indicator for data -hold mode 9 REL Indicator for relative measurement mode 10 C Temperature measuring unit 11 V, mv A, ma, µa MΩ, kω, Ω The unit of voltage The unit of current The unit of resistance 12 OL Overrange indication 5. Accessories user manual test leads 'K'-type thermocouple multifunctional socket 6. Operating Instructions 6.1. Data-Hold Mode Press the HOLD button to activate the data-hold mode ("DATA-H" is displayed). Enabling this function in the autorange mode makes the device switch to manual ranging mode. The measured value is saved and the selected range remains the same. Cancel the data-hold function by changing the measurement mode, pressing the RANGE button or pressing the HOLD button again. 6.2. Manual Ranging and Autorange Mode In the autorange mode the meter automatically selects the best range, allowing you to switch test points without having to reset the range. In the manual mode the user selects the range, making it possible to lock the meter in a specific range. AUTO is displayed when the device is in the autorange mode. The autorange mode is the default mode for measurement functions involving more than one range. Press the RANGE button to enter the manual ranging mode (AUTO is erased from the display). The range increases every time RANGE is pressed. The meter jumps to the lowest range if you press RANGE while the highest range is selected. Exit the manual ranging mode by holding the RANGE button for two seconds. The meter returns to the autorange mode and AUTO is displayed. 3
6.3. Battery Saver The standby mode is activated when no button is pressed for 30 minutes. Press HOLD or turn the selector to return to the normal display mode. You can deactivate this feature by holding the yellow button when you turn on the device. 6.4. Relative Measurement Mode The meter displays relative measurements for all functions except frequency measurements. Choose the desired function with the selector and touch a circuit with the test leads. This circuit now forms the basis for all future relative measurements. Press the REL button to store the measured value and activate the relative measurement mode. The difference between the reference value and subsequent reading is displayed. Hold the REL button for more than 2 seconds to return to the normal operation mode. 6.5. AC and DC Voltage Measurements Do not attempt to measure voltages in excess of 1000VDC or AC rms. Do not apply more than 1000VDC or AC between the common terminal and earth ground to protect the device from damage. The meter measures voltages in the following ranges : 400mV, 4000V, 40V, 400V and 1000V (the 400mV AC range is only available in the manual ranging mode. 1. Put the selector in the DCV, ACV or DCmV range. 2. Connect the black test lead with the COM jack and the red test lead with the V jack. 3. Connect the test leads with the circuit under test. 4. Read the display. The polarity of the red lead is indicated in case of a DCV measurement. Remarks : The device may display unstable readings, especially in the 400mV range, even though no test leads are connected with input terminals. Make contact between the measuring tips of the leads connected to the COM and V jacks in order to short these jacks if you suspect that the displayed value is incorrect. The display should read 0V. Measure the AC voltage first for increased accuracy when measuring the DC component of an AC voltage. Take note of this voltage and select a DC range higher than or equal to the measured AC voltage. This improves the accuracy of the DC measurement and keeps the input protection from activating. 6.6. Resistance Measurements Disconnect the circuit to be tested and make sure that all capacitors are fully discharged before measuring the incircuit resistance. The meter measures resistances in the following ranges : 400Ω, 4000kΩ, 40kΩ, 400kΩ, 4000MΩ and 40MΩ. 1. Select the Ω range with the selector 2. Connect the black test lead with the COM and the red test lead with the VΩ terminal. 3. Connect the test leads with the circuit under test and read the displayed value. Tips : In order to ensure the greatest accuracy when measuring low resistances : short the test leads prior to measurement and memorise the test probe resistance. Subtract the test probe resistance from the actual measured value. Do not use the 40MΩ range for in-circuit resistance measurements. The device may need a few seconds to produce a stable reading in the 40MΩ range, which is normal when measuring high resistances. The overrange indication 1 is displayed when the input is not connected e.g. in case of an open circuit 4
6.7. Diode Test Disconnect circuit power and discharge all capacitors before testing diodes. 1. Put the selector in the Ω range. 2. Press the yellow key once to activate the diode test. 3. Connect the black test lead with the COM and the red test lead with the VΩ jack. 4. Connect the red lead with the anode and the black lead with the cathode of the diode to be tested. 5. The device displays the approx. forward voltage of the diode. 6.8. Continuity Test Deactivate the circuit to be tested and make sure all capacitors have been fully discharged prior to measuring the circuit s continuity. 1. Put the selector in the Ω range. 2. Press the yellow button twice to activate the continuity test mode. 3. Connect the black lead with the COM jack and the red test lead with the Ω jack. 4. Connect the test leads with two points of the circuit to be tested. 5. The built-in buzzer sounds if continuity exists. 6.9. Capacitance Measurements Disconnect the test leads from the circuits to be measured before testing a capacitor in order to avoid electroshocks. Also make sure the capacitors have been discharged fully before inserting them into the socket. The device measures capacitance in the following ranges : 50.00nF, 500.0nF, 5.000µF, 50.00µF and 100.0µF. The device may need a few seconds to produce a stable reading, which is normal when measuring high capacitance values. Note that accuracy for measurements below 500pF is not guaranteed. Subtract the residual capacitance of the meter and the leads to improve the accuracy of measurements < 50nF. 1. Put the selector in the range. 2. Connect the black lead with the COM jack and the red test lead with the jack (or use the multifunctional socket). 3. Make sure the capacitor has been fully discharged and connect the test leads with the capacitor to be tested. 4. Read the value from the LCD. 6.10. Frequency and Duty Cycle Measurements 1. Put the selector in an AC voltage or AC current range and press the Hz % button. 2. Read the frequency of the AC signal from the display. 3. Press the Hz % button again to make a duty cycle measurement. 4. Read the percentage of duty cycle from the display. Notes : Use shielded cable to measure small signals in a noisy environment. Do not measure frequencies > 1000V to avoid electroshocks or damage to the device. 5
6.11. Temperature Measurements Do not connect the thermocouples with electrical circuits in order to avoid electroshocks. Do not use this device when voltages on the measurement surface exceed 60V DC or 24V rms. AC. Do not measure temperatures in a microwave oven. 1. Put the selector in the C position and read the current ambient temperature from the LCD. 2. Connect K-thermocouples with the COM and the C terminals (or use the multifunctional socket). Observe the polarity! 3. Touch the test object with the thermocouple. 4. Read the stable temperature from the LCD. 6.12. Current Measurements Do not perform current measurements on circuits with a potential > 600V above earth ground in order to avoid user injury and damage to the device. Check the fuse before you start your measurements. Use the proper terminals, function and range for your measurement. Never measure voltages (do not perform parallel measurements) when the selector is positioned on a current range. This device measures currents in the following ranges : 400µA, 4000µA, 40mA, 400mA, 4000A and 10A 1. Deactivate the circuit to be tested before connecting it to the meter and discharge all capacitors. 2. Put the selector in the µa, ma or A range. 3. Press the yellow button to select DCA or ACA measuring mode. 4. Connect the black test lead with the COM jack and the red test lead with the ma jack for measurements up to 400mA. Move the red test lead to the A jack for measurements up to 10A. 5. Cut the circuit to be tested. Touch the more negative side of the break with the black test tip. Touch the more positive side of the break with the red test tip. Switch the two test tips in case of a negative reading. 6. Turn on the power to the circuit and read the display. Be sure to note the measurement units at the right side of the display (µa, ma or A). When only "OL" is displayed, it indicates overrange situation and the higher range has to be selected. 7. Turn off power to the circuit and discharge all capacitors. Remove the meter and restore the circuit to normal operation. 7. Specifications Max. accuracy is achieved during a one-year period after calibration. Ideal circumstances require a temperature of 18 to 28 C (64 to 82 F) and a max. relative humidity of 75%. 7.1 Voltage Input Impedance (nom.) DC mv (mv ) 400mV 0.1mV ± 1.0% of rdg + 10 digits 4V 1mV DC voltage (V ) 40V 10mV ± 0.5% of rdg + 3 digits > 10MΩ < 100pF 400V 100mV 1000V 1V AC voltage (V ) 400mV 0.1mV ± 3.0% of rdg + 3 digits 4V 1mV 40V 10mV ± 1.0% of rdg + 3 digits > 5MΩ < 100pF 400V 100mV 1000V 1V Overload protection : 1000V DC or AC rms 6
Frequency range for AC voltage measurements : 40-500Hz Response for AC voltage measurements : average, calibrated in rms of a sine wave The 400mV range is a strictly manual range 7.2 Frequency 7.3 Resistance 7.4 Diode Test Frequency Hz (10Hz - 100KHz) 50Hz 0.01Hz 500Hz 0.1Hz ± 0.1% of rdg + 3 digits 5000Hz 0.001Hz 50KHz 0.01Hz 100KHz 0.1Hz Overload protection : 1000V DC or AC rms Resistance Ω 400Ω 0.1Ω ± 0.5% of rdg + 3 digits 4000kΩ 1Ω 40kΩ 10Ω ± 0.5% of rdg + 2 digits 400kΩ 100Ω 4000MΩ 1kΩ 40MΩ 10kΩ Overload protection : 1000V DC or AC rms Function Range Resolution Test Condition Accuracy Diode test 1V 0.001V forward DC current ± 1mA reversed DC voltage ± 1.5V ± 1.0% Overload protection : 1000V DC of AC rms 7.5 Continuity Test Function Range Resolution Description Test Condition Continuity 400Ω 0.1Ω continuity buzzer 75Ω open-circuit voltage : ± 0.5V Overload protection : 1000V DC of AC rms 7.6 Capacitance Capacitance 50nF 10pF <10nF: ± [5.0% of (rdg - 50 digits) +1 digit] ± 3.0% of rdg + 10 digits) 500nF 100pF 5µF 1nF ± (3.0% of rdg + 5 digits) 50µF 10nF 100µF 100nF Overload protection : 1000V DC or 1000V AC rms 7
7.7 Temperature -55 to 0 C 0.1 C ± 9.0% of rdg + 2 C degrees Celsius ( C) 1 to 400 C 0.1 C ± 2% of rdg + 1 C 401 to 1000 C 1 C ± 2% of rdg Overload protection : 1000V DC or 1000V AC rms 7.8 Current DC current 400µA 0.1µA µa 4000µA 1µA DC current 40mA 0.01mA ma 400mA 0.1mA DC current 4A 1mA A 10A 10mA AC current 1, 2 400µA 0.1µA µa 4000µA 1µA AC current 1, 2 400mA 0.01mA ma 400mA 0.1mA AC current 1, 2 4A 1mA A 10A 10mA Overload protection : F 10A/600V fuse for A range, F 500mA/600V fuse for µa and ma ranges Maximum input current : 400mA DC or AC rms for µa and ma ranges, 10A DC or AC rms for A ranges. For measurements > 5A : max. 4 minutes of uninterrupted measuring followed by 10 min. OFF, unknown above 10A 1 : frequency range 40Hz - 200Hz 2 : average response, calibrated in rms of a sine wave 8. Maintenance 8.1. General Always disconnect the test leads from all current sources before opening the meter. Protect the device against water to avoid electroshocks. Use a damp cloth and a mild detergent to clean the device. Never apply abrasives or solvents to the meter. Dirt or moisture in the terminals can affect the readings. Clean the terminals periodically: turn the device off and remove all test leads. Use a mild cleaning agent to clean the terminals. 8.2. Replacing the Fuse 1. Put the selector in the OFF position. 2. Disconnect all test leads and/or any connectors from any circuit under test. 3. Open the battery cover with a screwdriver and remove it. 4. Gently remove the fuse. 5. Install a new fuse with the following ratings : F 10A/600V Ø6.3x32 and F 500mA/600V Ø5x20 6. Screw the battery compartment closed again. 8
8.3. Battery Replacement Replace the batteries immediately when the low-battery indicator appears ( ). In order to avoid electroshocks, you should disconnect the test leads before opening the case or the battery compartment. 1. Put the selector in the OFF position. 2. Disconnect all test leads and/or any connectors from circuits under test. 3. Open the battery cover with a screwdriver and remove it. 4. Remove the old batteries and insert three new AAA-batteries of 1.5V 5. Close the battery compartment again. 9