Aneng SZ18 Digital Multimeter User Manual

LCD Display

The multimeter's LCD display shows various readings and indicators. Key elements include:

• AUTO: Indicates auto-ranging mode. The product selects the range with the best resolution.
• MANU: Indicates manual range mode. The user selects the range.
• F: Capacitance test (Farad).
• Δ: Relative mode indicator.
• Diode Symbol: Diode test mode.
• Continuity Symbol: Continuity test mode.
• %: Duty cycle test mode.
• Secondary Display: Shows secondary measurements.
• AC/DC Symbols: Indicate AC or DC current/voltage.
• T-RMS: Indicates True RMS measurement capability for sinusoidal and nonsinusoidal waveforms.
• Battery Symbol: Indicates low battery.
• Negative Reading Symbol: Indicates a negative reading.
• HOLD: Indicates the display is frozen on the current reading.
• V.F.C: Frequency converter test mode.
• MAX/MIN: Displays maximum or minimum values.
• Measurement Units: Displays units like Hz, V, A, Ω, %, °C, °F, mF, µF, mA, µA.
• Analog Bar Graph: Visual representation of the measurement.
• Primary Measurement Display: Shows the main measurement result.

Function Buttons

The multimeter features several buttons for operation:

• SELECT/V.F.C: Short press to switch among functions. Long press to enter V.F.C function.
• RANGE/REL: Short press to change range. Push for more than 2 seconds to enter relative mode. The product stores the present reading as a reference, zeroes the display, and subtracts the stored reading from subsequent readings. Long-press again to exit relative mode.
• MAX/MIN: Press to switch MAX/MIN test. Long press for 2 seconds to quit MAX/MIN mode.
• HOLD: Push once to hold the current reading. Push again to continue normal operation. Long press for over 2 seconds to turn on the flashlight; long press again to turn off the flashlight.

Rotary Button

The rotary button selects measurement modes. The OFF position turns off the product.

• The product automatically powers off after 15 minutes of inactivity.
• A built-in beeper sounds 5 times 1 minute before auto power off.
• To restart from auto power off, press the SELECT button or turn the rotary switch back to OFF and then to a needed position.
• To disable Auto Power Off: Hold down the SELECT button while turning on the product. Five beeps indicate successful disabling.

Measure AC/DC Voltage

1. Connect the black test lead to the COM Terminal and the red lead to the VΩHz+ Terminal.
2. To measure voltage under 99.99mV, turn the rotary to the mV range. To measure voltage higher than 99.99mV, turn the rotary to the V range. Press SELECT to switch to AC voltage test mode if needed.
3. Touch the probes to the correct test points of the circuit to measure the voltage.
4. Read the measured voltage on the screen.

*Do not measure voltage that exceeds the extremes as indicated in the Specifications. *Do not touch high voltage circuits during measurements.

Measure AC/DC Current

1. Connect the black test lead to the COM Terminal and the red lead to the A or µA/mA Terminal (choose based on the value of the current to be measured).
2. Turn the rotary to µA, mA, or A.
3. Break the circuit path to be measured, connect the test leads across the break, and apply power.
4. Read the measured current on the display.

*Do not measure current that exceeds the extremes as indicated in the Specifications. *Use the mA Terminal when measuring unknown current, then switch to the µA Terminal if necessary. *Do not input voltage at this setting.

Measure Resistance

1. Connect the black test lead to the COM Terminal and the test lead to the VΩHz+ Terminal.
2. Turn the rotary to the Ω symbol, press SELECT to enter Resistance Mode. The screen will show "OL" if the resistance is too high.
3. Touch the probes to the desired test points of the circuit to measure the resistance.
4. Read the measured resistance on the display.

*Disconnect circuit power and discharge all capacitors before you test resistance. *Do not input voltage at this setting.

Test Diodes and Continuity

1. Connect the black test lead to the COM Terminal and the red lead to the VΩHz+ Terminal.
2. Turn the rotary to the Diode/Continuity symbol (often combined with Ω), press SELECT to enter the continuity Mode.
3. To test continuity, touch the probes to the desired test points of the circuit. The built-in beeper will beep when there is a short circuit (low resistance).
4. To test diodes, connect the red probe to the anode side and the black probe to the cathode side of the diode being tested. Then read the forward bias voltage value on the display. If the polarity of the test leads is reversed or the diode is broken, the display reading shows "OL".

*Do not input voltage at this setting. *Disconnect circuit power and discharge all capacitors before you test diode.

Measure Capacitance

1. Connect the black test lead to the COM Terminal and the red lead to the VΩHz+ Terminal.
2. Turn the rotary to the Capacitance symbol (F), press SELECT to enter capacitance Mode.
3. Connect the red probe to the anode side and the black probe to the cathode side of the diode being tested (for diode capacitance measurement, though typically capacitance is measured across component leads). For general capacitance measurement, connect probes to the component leads.
4. Read the measured capacitance value on the display once the reading is stabilized.

*Disconnect circuit power and discharge all capacitors before you test diode.

Measure Frequency and Duty Cycle

1. Connect the black test lead to the COM Terminal and the red lead to the VΩHz+ Terminal.
2. Turn the rotary switch to the Frequency/Duty Cycle symbol (often combined with V.F.C or Hz), press SELECT to enter frequency test function (for ≥10V, 1~100KHz); or turn the rotary switch to the Hz mV range, press SELECT to enter frequency test function (for ≤10V, 1~5MHz).
3. If the frequency is between 100kHz and 5MHz, press SELECT to enter AC mV position. Touch the probes to the desired test points; the vice display will show frequency. Then press SELECT again; the main display will show frequency and the vice display will show duty cycle.

Measure Temperature

1. Connect the black test lead to the COM Terminal and the red lead to the VΩHz+ Terminal.
2. Turn the rotary to the Temperature symbol (°C/°F), press SELECT to enter the temperature Mode. The main display will show Celsius and the vice display will show Fahrenheit.
3. Touch the probes to the desired test points.
4. Read the measured temperature on the display.

*Do not input voltage at this setting.

Test NCV (Non-Contact Voltage)

1. Turn the rotary to the NCV position, press SELECT to enter the NCV Mode.
2. Hold the product and move it around. The built-in beeper will beep when the inner sensor detects AC voltage nearby. The stronger the voltage is, the quicker the beeper beeps.

Measure V.F.C (Voltage to Frequency Converter)

1. Connect the black test lead to the COM Terminal and the red lead to the VΩHz+ Terminal.
2. Turn the rotary to the V.F.C symbol, long press SELECT to enter V.F.C mode. The screen will show voltage when the test leads are placed at the correct circuit.

Measure Square Wave

1. Connect the black test lead to the COM Terminal and the red lead to the VΩHz+ Terminal.
2. Turn the rotary switch to the Square Wave/Output symbol (often combined with V.F.C), and the default output frequency is 50Hz. To change the output frequency, press the SEL button.
3. Touch the probes to the desired test points.

*Do not input voltage at this setting.

Clean the Product

Wipe the product with a damp cloth and mild detergent. Do not use abrasives or solvents. Dirt or moisture in the terminals can affect readings. *Remove the input signals before you clean the product.

Replace the Batteries

When the low battery symbol (?) is shown on the display, batteries shall be replaced as follows:

1. Remove the test leads and turn off the product before replacing the batteries.
2. Loosen the screw on the battery door and remove the battery door.
3. Replace the used batteries with new batteries of the same type (1.5V AAA * 3).
4. Place the battery door back and fasten the screw.

Replace the Fuses

When a fuse is blown or does not work properly, it shall be replaced as follows:

1. Remove the test leads and turn off the product before replacing the fuse.
2. Loosen the four screws on the back cover and the screw on the battery door, then remove the battery door and the back cover.
3. Replace the fuse with a new fuse of the same type.
4. Place the back cover and the battery door back and fasten the screws.

General Specifications

Mechanical Specifications

Environmental Specifications

Electrical Specifications

*Frequency response of ACV: 40Hz-1kHz