1. Introduction
This manual provides essential information for the safe and effective operation of your UNI-T Digital Multimeter. Please read this manual thoroughly before use and keep it for future reference. UNI-T multimeters are versatile tools designed for electrical measurements in various applications, from basic home use to professional industrial settings.
Product Overview Video
2. Safety Information
Always observe safety precautions when using any electrical testing equipment. Failure to do so may result in injury or damage to the meter or equipment under test.
- Ensure the meter is in good working condition before use.
- Do not apply voltage or current that exceeds the maximum rated input for the meter.
- Use appropriate personal protective equipment (PPE), such as insulated gloves and safety glasses.
- Never use the meter on circuits with voltages exceeding its CAT rating.
- Replace batteries and fuses only with the specified type and rating.
- Avoid using the meter in wet environments or during electrical storms.
3. Product Features and Components
UNI-T Digital Multimeters offer a range of features depending on the model. Common features include:
- AC/DC Voltage and Current Measurement
- Resistance, Capacitance, and Frequency Measurement
- Diode and Continuity Test
- Non-Contact Voltage (NCV) Detection
- Temperature Measurement (with appropriate probe)
- True RMS for accurate AC measurements
- Automatic Range and Automatic Shutdown
- Data Hold and Max/Min functions
- Backlight for low-light conditions
4. Setup
4.1 Battery Installation
Most UNI-T multimeters require AA or AAA batteries. Refer to your specific model's battery compartment for details.
- Turn off the multimeter and disconnect all test leads.
- Locate the battery compartment cover on the back of the meter.
- Use a screwdriver to open the cover.
- Insert new batteries, observing the correct polarity (+ and -).
- Replace the cover and secure it with the screw.
4.2 Connecting Test Leads
Always connect the black test lead to the 'COM' (common) jack. Connect the red test lead to the appropriate input jack for your measurement (e.g., 'VΩmA' for voltage/resistance/small current, 'A' for high current).
5. Operating Instructions
The following are general operating guidelines. Always refer to the specific instructions for your multimeter model.
5.1 Basic Measurements
- Voltage Measurement (AC/DC):
- Turn the rotary switch to the V~ (AC Voltage) or V- (DC Voltage) position.
- Connect the black test lead to the COM jack and the red test lead to the VΩmA jack.
- Connect the test probes in parallel to the circuit or component being measured.
- Read the voltage value on the display.
- Current Measurement (AC/DC):
- Turn the rotary switch to the A~ (AC Current) or A- (DC Current) position. Select the appropriate range (mA or A).
- Connect the black test lead to the COM jack. Connect the red test lead to the mA or A jack, depending on the expected current.
- Connect the test probes in series with the circuit.
- Read the current value on the display.
- Resistance Measurement:
- Turn the rotary switch to the Ω position.
- Connect the black test lead to the COM jack and the red test lead to the VΩmA jack.
- Connect the test probes across the component to be measured. Ensure the circuit is de-energized.
- Read the resistance value on the display.
- Continuity Test:
- Turn the rotary switch to the Ω or ))) position.
- Connect the test leads as for resistance measurement.
- Touch the probes to the two points of the circuit. A continuous beep indicates continuity.
- Diode Test:
- Turn the rotary switch to the Ω or ))) position, then press 'SELECT' to choose diode test.
- Connect the test leads as for resistance measurement.
- Connect the red probe to the anode and the black probe to the cathode of the diode. Read the forward voltage drop. Reverse the probes to check for open circuit.
5.2 Advanced Features
- Non-Contact Voltage (NCV): Many models feature NCV detection. Place the NCV sensor near a live conductor to detect AC voltage without contact. The meter will indicate with an audible beep and/or LED light.
- Temperature Measurement: For models like UT890C and UT89X, connect a K-type thermocouple to the meter and select the temperature function. The UT890C can measure from -40°C to 1000°C.
- LED Test Function (UT89XD only): The UT89XD model can output approximately 12V/5mA voltage for testing LEDs.
- High Voltage Measurement (UT892): The UT892 model supports AC/DC voltage measurement up to 2000V. It features a high voltage red backlight alarm for measured values over 1500V.
6. Maintenance
6.1 Cleaning
Wipe the meter casing with a damp cloth and mild detergent. Do not use abrasives or solvents.
6.2 Battery Replacement
When the battery indicator appears on the display, replace the batteries as described in the Setup section (4.1 Battery Installation).
6.3 Fuse Replacement
If the meter fails to measure current, the fuse may be blown. Refer to the specific model's manual for fuse specifications and replacement instructions. Always use a fuse with the correct voltage and current rating.
7. Troubleshooting
- No display or dim display: Check battery level and replace if necessary.
- Incorrect readings: Ensure correct function selection, proper test lead connection, and that the circuit is within the meter's measurement range.
- No current measurement: Check and replace the fuse if blown.
- 'OL' or 'OVER' on display: Indicates an overload or out-of-range measurement. Select a higher range or check the circuit.
8. Specifications
Specifications vary by model. Below are tables for common models. Always refer to your specific model's documentation for precise details.
8.1 UT890C / UT890D+ Specifications
8.2 UT105+ / UT107+ Technical Indicators
8.3 UT89X / UT89XD / UT89XE Data Parameters
8.4 UT123 / UT123D Technical Parameters
9. User Tips
- Always start with the highest range when measuring an unknown voltage or current to prevent damage to the meter.
- For accurate resistance readings, ensure the component is isolated from the circuit.
- Utilize the 'HOLD' function to freeze a measurement on the display for easier reading in difficult positions.
- The 'MAX/MIN' function is useful for capturing transient peaks or troughs in measurements over time.
- Keep your multimeter clean and store it in a protective case to prolong its lifespan.
10. Warranty and Support
UNI-T products are designed for reliability and performance. For warranty information, technical support, or service, please contact your local UNI-T distributor or visit the official UNI-T website. Keep your purchase receipt as proof of purchase.
