RuoShui 8045-II Digital Multimeter

1. Introduction

The RuoShui 8045-II is a high-precision benchtop digital multimeter designed for laboratories, factories, radio hobbyists, and general household use. It features a 19999-count True RMS display, offering strong stability and accurate measurements for various electrical parameters including AC/DC voltage, AC/DC current, resistance, capacitance, frequency, and transistor hFE.

2. Package Contents

Please check the package contents upon receipt to ensure all items are present and undamaged:

• Packing Box
• RuoShui 8045-II Desktop Multimeter
• Power Cable
• Adapters (if applicable)
• Test Leads (red and black)
• Product Manual (this document)

3. Product Overview

Familiarize yourself with the components and controls of your RuoShui 8045-II Digital Multimeter.

3.1 Front Panel Controls and Display

1. LCD Display: 19999-count digital display with VA reverse display, 4 1/2 digits of precision, and symbol display.
2. Screen Switch: Toggles the display on/off.
3. Data Hold Button (HOLD): Freezes the current reading on the display.
4. Relative Value Button (REL): Measures the relative value by subtracting a stored reference value.
5. AC+DC Selector Switch: Toggles between AC and DC measurement modes.
6. Max/Min Button (MAX/MIN): Records and displays the maximum or minimum measured value.
7. Range Knob: Rotary switch to select measurement functions and ranges.
8. Common Input (COM): Negative input terminal for all measurements.
9. V/Ω/Hz Input: Positive input terminal for Voltage, Resistance, and Frequency measurements.
10. 200mA Input Terminal: Positive input terminal for current measurements up to 200mA.
11. 2/20A Input Terminal: Positive input terminal for high current measurements up to 20A (10 seconds max, 20A fused).

3.2 Rear Panel Features

12. Voltage Transfer Switch: Selects between 110V and 220V AC input for power.
13. Power Switch: Main power on/off switch for the device.
14. Fuse Box: Contains the main power fuse (200mA/250V) for protection.
15. Power Outlet: AC power input socket.

3.3 Key Features

• True RMS Measurement: Provides accurate readings for non-sinusoidal AC waveforms.
• Auto Range: Automatically selects the appropriate measurement range.
• Backlit Display: Improves readability in low-light conditions.
• Low Voltage Alert: Indicates when the internal battery (if used for memory/RTC, though main power is AC) is low.
• Bracket Design: The instrument stand can be rotated for optimal viewing angles, allowing for horizontal placement, supported use, or handheld operation.

4. Setup and Initial Operation

4.1 Power Connection

1. Ensure the multimeter's main power switch (13) on the rear panel is in the 'OFF' position.
2. Verify the Voltage Transfer Switch (12) is set to the correct voltage for your region (110V or 220V).
3. Connect the provided power cable to the Power Outlet (15) on the rear panel and then to a suitable AC power source.
4. Flip the Power Switch (13) to the 'ON' position. The LCD display should illuminate.

4.2 Test Lead Connection

Always connect the test leads to the correct input terminals for the desired measurement to prevent damage to the multimeter or the circuit being tested.

• Connect the black test lead to the COM (Common) input terminal (8).
• For Voltage (V), Resistance (Ω), Frequency (Hz), and Capacitance (Cx) measurements, connect the red test lead to the V/Ω/Hz input terminal (9).
• For current measurements up to 200mA, connect the red test lead to the 200mA input terminal (10).
• For high current measurements up to 20A, connect the red test lead to the 2/20A input terminal (11).

5. Operating Instructions

This section provides general guidelines for using your multimeter. Always refer to the specific measurement function on the range knob and ensure proper test lead connections.

5.1 General Measurement Procedure

1. Connect the test leads as described in Section 4.2 for the desired measurement.
2. Turn the Range Knob (7) to the appropriate function and range. If unsure, start with a higher range or use the 'AUTO' setting if available for that function.
3. Connect the test probes to the circuit or component to be measured.
4. Read the value on the LCD Display (1).
5. After measurement, disconnect the test leads from the circuit, then from the multimeter. Turn the range knob to 'OFF' or a safe position.

5.2 Specific Measurement Functions

5.2.1 Resistance Measurement

To measure resistance, turn the range knob to the 'Ω' (Ohm) setting. Connect the test leads to the V/Ω/Hz (red) and COM (black) terminals. Place the probes across the component to be measured. The display will show the resistance in Ohms (Ω), kilo-Ohms (kΩ), or Mega-Ohms (MΩ).

5.2.2 Diode Measurement

Turn the range knob to the diode symbol (▶|). Connect the test leads to the V/Ω/Hz (red) and COM (black) terminals. Place the red probe on the anode and the black probe on the cathode of the diode. The display will show the forward voltage drop. Reverse the probes to check for reverse bias; an 'OL' (Overload) reading indicates a good diode in reverse bias.

5.2.3 Capacitance Measurement

Turn the range knob to the 'Cx' (Capacitance) setting. Connect the test leads to the V/Ω/Hz (red) and COM (black) terminals. Ensure the capacitor is discharged before testing. Place the probes across the capacitor terminals. The display will show the capacitance in Farads (F), micro-Farads (µF), nano-Farads (nF), or pico-Farads (pF).

5.2.4 Voltage Measurement (AC/DC)

Turn the range knob to 'V=' for DC voltage or 'V~' for AC voltage. Connect the test leads to the V/Ω/Hz (red) and COM (black) terminals. Connect the probes in parallel with the circuit or component where voltage is to be measured. Use the AC+DC selector switch (5) if needed for combined AC+DC measurements.

5.2.5 Current Measurement (AC/DC)

Turn the range knob to the appropriate 'A=' for DC current or 'A~' for AC current range (e.g., 200mA, 2A, 20A). Connect the test leads to the COM (black) and either the 200mA (10) or 2/20A (11) input terminal (red), depending on the expected current. Connect the multimeter in series with the circuit. Ensure the circuit is de-energized before connecting the multimeter in series.

5.2.6 Frequency Measurement

Turn the range knob to the 'Hz' (Frequency) setting. Connect the test leads to the V/Ω/Hz (red) and COM (black) terminals. Connect the probes to the signal source. The display will show the frequency in Hertz (Hz), kilo-Hertz (kHz), or Mega-Hertz (MHz).

5.2.7 Transistor (hFE) Measurement

Turn the range knob to the 'hFE' setting. Insert the transistor leads into the appropriate NPN or PNP sockets on the front panel. The display will show the hFE value.

6. Maintenance

6.1 Cleaning

To clean the multimeter, wipe the case with a damp cloth and a mild detergent. Do not use abrasives or solvents. Ensure the device is powered off and disconnected from all power sources and circuits before cleaning.

6.2 Fuse Replacement

The multimeter is protected by a fuse located in the fuse box (14) on the rear panel. If the multimeter fails to power on or a current measurement range stops working, the fuse may need replacement.

1. Ensure the multimeter is powered off and disconnected from the AC power source.
2. Locate the fuse box (14) on the rear panel.
3. Carefully open the fuse box cover.
4. Remove the old fuse and replace it with a new fuse of the specified rating: 200mA/250V.
5. Close the fuse box cover securely.

Warning: Always replace fuses with ones of the identical type and rating to prevent fire or electric shock hazards.

7. Troubleshooting

If you encounter issues with your RuoShui 8045-II Multimeter, try the following basic troubleshooting steps:

• No Display/No Power: Check the power cable connection, ensure the power switch is ON, and verify the fuse (see Section 6.2).
• 'OL' (Overload) Reading: This indicates the measured value exceeds the selected range. Switch to a higher range or ensure the component is not open-circuited (for resistance) or short-circuited (for current).
• Inaccurate Readings: Ensure test leads are correctly connected and fully inserted. Check for damaged test leads. Verify the correct function and range are selected.
• No Reading for Current: Ensure the multimeter is connected in series with the circuit and the correct current input terminal (200mA or 2/20A) is used. Check the fuse for the current range.
• Display Flickering: Ensure stable power supply.

If problems persist after attempting these steps, please contact customer support.

8. Specifications

9. User Tips

• Always ensure the multimeter is set to the correct function and range before connecting to a circuit.
• For voltage measurements, connect the multimeter in parallel with the component. For current measurements, connect it in series.
• When measuring resistance or capacitance, ensure the component is isolated from the circuit and fully discharged.
• Utilize the 'HOLD' function to freeze readings for easier recording, especially in hard-to-reach areas.
• The 'MAX/MIN' function is useful for capturing transient peaks or dips in measurements over time.
• Keep the display backlight on in dimly lit environments for better visibility.

10. Warranty and Support

For any questions, technical assistance, or warranty claims regarding your RuoShui 8045-II Digital Multimeter, please contact the seller or manufacturer directly. Keep your purchase receipt as proof of purchase.