RuoShui 8145C Automatic Digital Multimeter User Manual

1. Introduction

This manual provides essential information for the safe and effective operation of the RuoShui 8145C Automatic Digital Multimeter. Please read this manual thoroughly before using the instrument and keep it for future reference.

Figure 1: RuoShui 8145C Smart Desktop Multimeter. Features include 4 1/2 digit display, True RMS measurement, Voltage, Current, Backlit display, Data hold, USB data transfer, and Large screen display.

2. Safety Information

Always observe the following safety precautions when operating the multimeter:

• Ensure the correct function and range are selected before making measurements.
• Do not exceed the maximum input values for any range.
• Use caution when working with voltages above 60V DC or 30V AC RMS.
• Disconnect test leads from the circuit before changing functions.
• Replace fuses only with the specified type and rating.
• Do not operate the meter if it appears damaged or if the case is open.

3. Package Contents

Verify that all items listed below are included in your package:

• Desktop Multimeter (RuoShui 8145C)
• Product Manual
• Software CD
• USB Serial Communication Line
• Test Leads
• Power Cable
• Test Clips
• RS232 Connection Line (for some models)

Figure 2: Packaging Accessories for the RuoShui 8145C Digital Multimeter.

4. Product Overview

4.1 Front and Rear Panel

Figure 3: Front and Rear Panel Components.

1. Display screen
2. Backlight button
3. Auto/manual range button
4. Instrument configuration key (Config)
5. Function selection keys (DCV, DCA, Ω, ACV, ACA, Hz, REL, RATE, TEMP, HOLD, MAX/MIN/AVG)
6. Input terminals (VΩ, COM, mA, 10A)
7. Power selection switch
8. Switch
9. Fuse box
10. Power connector
11. USB interface

4.2 Display Features

• White LED backlight
• Adjustable backlight time
• 4 1/2 digits precision
• Symbol display for various functions

Figure 4: Segment LCD Display and Multimeter Dimensions.

5. Setup

5.1 Power Connection

Connect the provided power cable to the power connector (10) on the rear panel of the multimeter and then to a suitable AC power outlet. Ensure the power selection switch (7) is in the correct position for your local voltage (AC 110V/220V).

5.2 USB Connection (Optional)

The multimeter can be connected to a computer for data transfer and analysis using the provided USB serial communication line. Connect one end to the USB interface (11) on the rear panel and the other to your computer's USB port. Install the software from the included CD.

Figure 5: Desktop Multimeter and Computer Connection via USB.

6. Operation

Turn on the multimeter using the power switch (8). Select the desired measurement function using the function selection keys (5).

6.1 Function Demo Video

6.2 Basic Measurements

• Voltage (DCV/ACV): Connect test leads to VΩ and COM terminals. Select DCV or ACV function.
• Current (DCA/ACA): Connect test leads to mA or 10A and COM terminals. Select DCA or ACA function. Ensure correct current input terminal is used based on expected current.
• Resistance (Ω): Connect test leads to VΩ and COM terminals. Select Ω function.
• Capacitance: Connect test leads to VΩ and COM terminals. Select the capacitance function (often combined with Ω or a dedicated button).
• Frequency (Hz): Connect test leads to VΩ and COM terminals. Select Hz function.
• Diode Test: Connect test leads to VΩ and COM terminals. Select diode test function.
• Continuity Test: Connect test leads to VΩ and COM terminals. Select continuity function (often combined with Ω or diode test).
• Temperature (TEMP): Use a compatible temperature probe (not always included) connected to the appropriate terminals. Select TEMP function.

6.3 Advanced Functions

• Auto/Manual Range: Press the AUTO button (3) to switch between automatic and manual ranging. In manual mode, use the arrow keys to select the desired range.
• Backlight: Press the backlight button (2) to turn the display backlight on/off or adjust its settings.
• Data Hold (HOLD): Press the HOLD button to freeze the current reading on the display. Press again to release.
• MAX/MIN/AVG: Use these functions to record maximum, minimum, or average readings over a period.
• REL (Relative Measurement): This function measures the difference between a stored reference value and the current reading.
• Config: The instrument configuration key (4) allows access to advanced settings and calibration options. Refer to the software manual for detailed usage.

7. Maintenance

7.1 General Care

• Keep the multimeter clean and dry. Use a soft, damp cloth for cleaning; do not use abrasives or solvents.
• Store the instrument in a cool, dry place away from direct sunlight and extreme temperatures.
• Avoid dropping or subjecting the multimeter to strong impacts.

7.2 Fuse Replacement

If the current measurement function fails, the fuse may need replacement. Refer to the fuse box (9) location on the rear panel. Always replace with a fuse of the same type and rating as specified on the instrument (e.g., 250mA/250V for the mA input, 10A/250V for the 10A input).

8. Troubleshooting

• No Display/Power: Check power cable connection and ensure the power switch is ON. Verify the power outlet is functional.
• Incorrect Readings: Ensure test leads are correctly connected to the appropriate input terminals and the correct function/range is selected. Check battery level if applicable (though this is a bench-top model, some internal components might have backup batteries).
• "OL" or Overload Indication: The measured value exceeds the selected range. Switch to a higher range or verify the circuit.
• No Current Measurement: Check the fuse for the current input. Replace if blown.
• USB Connection Issues: Ensure the software is correctly installed and the USB cable is securely connected. Try a different USB port.

9. Specifications

The following table details the specifications for the RuoShui 8145C and 8246A models:

Figure 6: Detailed Specifications for 8145C and 8246A Models.

Note: Specifications are subject to change without notice. Refer to the latest product documentation for the most accurate information.

10. User Tips

• For precise resistance measurements, ensure test leads are properly calibrated or compensated for lead resistance.
• When measuring capacitance, ensure the capacitor is fully discharged before connecting the multimeter.
• Utilize the data hold function (HOLD) for stable readings in fluctuating environments.
• The MAX/MIN/AVG functions are useful for monitoring signal variations over time.

11. Warranty and Support

For warranty information, technical support, or service inquiries, please contact your local distributor or the manufacturer directly. Keep your purchase receipt as proof of purchase.