User's Guide Autoranging Multimeter Extech EX503
Introduction Congratulations on your purchase of the Extech EX503 Autoranging Multimeter. This meter measures AC/DC Voltage, AC/DC Current, Resistance, Capacitance, Frequency, Diode Test, and Continuity plus Thermocouple Temperature. It features a waterproof, rugged design for heavy duty use. Proper use and care of this meter will provide many years of reliable service.
CAUTIONS • Improper use of this meter can cause damage, shock, injury or death. Read and understand this user manual before operating the meter. • Always remove the test leads before replacing the battery or fuses. • Inspect the condition of the test leads and the meter itself for any damage before operating the meter. Repair or replace any damage before use. • Use great care when making measurements if the voltages are greater than 25VAC rms or 35VDC. These voltages are considered a shock hazard.
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 1000VDC/AC rms mA AC/DC 400mA AC/DC A AC/DC 10A AC/DC (20A for 30 sec) Frequency, Resistance, Capacitance, Diode Test, Continuity 600VDC/AC rms 2.
Controls and Jacks 1. 4,000 count LCD display 2. RANGE button 3. Hz and % button 4. Mode button 5. Function switch 6. mA, µA and 10A input jacks 7. COM input jack 8. Positive input jack 9. Backlight button 10. REL button 11. HOLD button Note: Tilt stand and battery compartment are on rear of unit.
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 the 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. DC VOLTAGE MEASUREMENTS CAUTION: Do not measure DC voltages if a motor on the circuit is being switched ON or OFF.
DC CURRENT MEASUREMENTS CAUTION: Do not make 20A current measurements 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 4000µA DC, set the function switch to the µA position and insert the red test lead banana plug into the µA/mA jack. 3.
RESISTANCE MEASUREMENTS WARNING: To avoid electric shock, disconnect power 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 Ω CAP position. 2. Insert the black test lead banana plug into the negative COM jack. Insert the red test lead banana plug into the positive Ω jack. 3. Press the MODE button to indicate “Ω" on the display. 4.
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. 1. Set the rotary function switch to the Ω CAP position. 2. Insert the black test lead banana plug into the negative COM jack. Insert the red test lead banana plug into the positive V jack. 3. Press the MODE button to indicate “nF” on the display. 4.
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.
Maintenance WARNING: To avoid electric shock, disconnect the test leads from any source of voltage before removing the back cover or the battery or fuse covers. WARNING: To avoid electric shock, do not operate your meter until the battery and fuse covers are in place and fastened securely. 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.
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. A B A B A F1 F2 REPLACING THE FUSES WARNING: To avoid electric shock, disconnect the test leads from any source of voltage before removing the fuse cover. 1. Disconnect the test leads from the meter. 2.
Specifications Function DC Voltage Range 400mV Resolution 0.1mV 4V 40V 400V 1000V 0.001V 0.01V 0.1V 1V ±(1.5% reading + 2 digits) 400mV 0.1mV ±(2.0% reading + 10 dgts) 4V 40V 400V 1000V 0.001V 0.01V 0.1V 1V ±(2.5% reading + 5 dgts) 400μA 0.1μA ±(1.0% reading + 3 digits) 4000μA 40mA 400mA 10A 1μA 0.01mA 0.1mA 0.01A ±(2.5% reading + 10 digits) AC Current 400μA 0.1μA ±(2.5% reading + 10 digits) Resistance 4000μA 40mA 400mA 10A 400Ω 1μA 0.01mA 0.1mA 0.01A 0.1Ω ±(3.
Function Duty Cycle Range 0.1 to 99.9% Resolution 0.1% Accuracy ±(1.2% reading + 2 digits) Pulse width: 100µs to 100ms, Frequency: 5Hz to 150kHz o o o o NOTE: Accuracy is stated at 65 F to 83 F (18 C to 28 C) and less than 75% RH. Note: Accuracy specifications consist of two elements: • (% reading) – This is the accuracy of the measurement circuit. • (+ digits) – This is the accuracy of the analog to digital converter. Enclosure Double molded, waterproof (IP67) Shock (Drop Test) 6.
