Victor 79A+ Digital Process Multimeter User Manual

1. Introduction

This manual provides detailed instructions for the safe and effective use of the RuoShui Victor 79A+ Digital Process Multimeter. Please read this manual carefully before operating the device.

General Description

The Victor 79A+ is an industrial, battery-powered instrument designed for field maintenance. It integrates the functionalities of a digital multi-meter and process signal sources. This meter conforms to safety standards IEC 61010-1 (600V CAT.IV and 1000V CAT.III) for Electrical Equipment for Measurement, Control, and Laboratory Use. Its dual-color plastic enclosure provides IP65 protection, making it suitable for harsh environments.

The device offers both measurement and output functions:

• Measurement functions: AC/DC voltage, Ohm, capacitance, DC/AC current, on-off test, diodes, frequency, thermocouples, thermal resistance. It also features data display and retention, and measurement of relative values.
• Output functions: DC voltage, resistance, frequency, thermocouples, thermal resistance, and DC current (constant output, manual stepping, and SIMULATE).
• Loop inspection: Supplies power to 24V circuits and simultaneously measures current, with a built-in 250 Ω HART loop resistance.

Packaging Accessories

Upon receiving the product, inspect it for any damage during transportation and ensure all components are present. Keep packaging materials for future transportation.

Standard accessories include:

• One multi-function calibrator (the main unit)
• One packing box
• One Product Manual (this document)
• One pair of testing wires (including an alligator clip)
• Four 1.5V alkaline cells (LR6) - Note: Batteries are not included in the package.
• One 500mA/250V quick-acting fuse
• One soft portable bag

Optional accessories:

• One power adapter

2. Safety Warnings

This meter is designed, produced, and inspected according to IEC 61010-1 safety standards. Adherence to the following warnings and regulations is crucial for safe operation and to prevent damage to the meter or personal injury.

Warning: Refers to an activity that may endanger the user.

Caution: Refers to an activity that may damage the meter or the tested equipment.

Notice: Refers to necessary understanding of meter operations and characteristics.

International Symbols

The label ⚠ marked on the meter indicates that the meter must be operated according to relevant instructions in this manual for safety purposes.

3. Setup and Basic Operation

Starting Up the Meter

To power on the meter, turn the rotary switch to any function position. The meter will perform a self-inspection and display relevant information on the screen before operations begin.

Notice: To ensure correct power-on operations, the meter should only be restarted after being powered off for at least 5 seconds.

Automatic Shutdown

By default, the meter will automatically switch off if no operation is performed within 10 minutes. If the meter automatically switches off, turn the rotary switch to the OFF position before restarting. The automatic shutdown function can be configured by the user (refer to "Meter Settings" section).

Notice: Automatic shutdown consumes approximately 300uA of current. It is recommended to turn the rotary switch to the OFF position when the meter is not in use to conserve battery life.

Low Battery Indication

The symbol + shown on the screen indicates low battery power. Replace the batteries as soon as possible.

Warning: To avoid electric shock or personal injury due to incorrect readings, replace batteries immediately when the + symbol is displayed.

Panel Introduction

The meter's panel features an LCD display, various buttons, a function knob, and input/output ports. Measurement functions are indicated by white characters, while output functions are indicated by yellow characters. Functions marked in blue on the rotary switch can be selected using the blue button.

Key components and their functions:

1. LCD display
2. Automatic/manual start and stop key
3. Relative value / 25%, 100% or digit-setting output
4. Backlight
5. Frequency/duty cycle/waveform output
6. Range gear knob
7. Input point for measurement (+)
8. Input point for loop power supply
9. Select leftwards
10. Select rightwards/change measuring speed
11. Decrease the setting value
12. Select the blue-button function
13. Increase the setting value
14. Common point
15. V/Ω Equal port
16. Adapter power supply hole
17. Pen slot
18. Bracket

Rotary Switch

Turn the rotary switch to any function position to start the meter. The meter will then display the standard screen for that function. When a new function is selected, the meter will default to automatic range mode. Settings for a specific function only apply to that function and do not affect others.

Rotary Switch Functions:

Buttons

The meter features several buttons for various operations:

• START/RANGE: In measurement mode, push to exit AUTO mode and enter manual range. Hold for 2 seconds to enter AUTO mode. In output mode, selects fixed output range (voltage/frequency) or indexing number (thermocouple/RTD), or starts/stops current output waveforms.
• REL ▲: In measurement mode, saves current reading as an error reference value. Press again to show difference in percentage.
• ON/OFF/HOLD: In measurement mode, enters/exits display hold. In output mode, connects/disconnects output.
• Hz %: In ACV measurement, selects frequency or duty cycle. In output mode, selects automatic ramp/stepping or digit-setting output for current waveforms, or switches frequency output display.
• Left/Right Arrows: Selects output setting digit.
• Up/Down Arrows: Increases/decreases setting digit value. For stepping output, steps up/down by 25% or 100%.
• Blue Button: Selects the blue-button function (alternative function on rotary switch).
• Backlight Button: Turns backlight on or off.

Display Screen

The LCD display provides various indicators and readings:

Input and Output Plugholes

The meter features specific plugholes for various inputs and outputs:

4. Operating Instructions

Range and Speed Selection

• Range Selection: In measurement mode, press the START/RANGE button to select a fixed range. The meter defaults to automatic range mode, selecting the lowest possible range for precision. To switch between auto and manual range, press START/RANGE. Hold for 2 seconds to return to auto range. For diode, on-off test, capacitance, frequency, and duty cycle functions, START/RANGE is not valid. RTD and TC are manual range only.
• Speed Selection: The default measurement speed is slow. Press the RATE button to change the measurement speed.

Measurement Functions

AC Voltage Measurement

1. Turn the rotary switch to the "V" position, then press the blue button to select AC voltage measurement.
2. Plug the black test lead into the "COM" plughole and the red test lead into the "VΩ" plughole.
3. Connect the test leads to the circuit to be measured and read the stable data.
4. Press the Hz % button to display frequency and duty cycle.

DC Voltage Measurement

1. Turn the rotary switch to the "V" position.
2. Plug the black test lead into the "COM" plughole and the red test lead into the "VΩ" plughole.
3. Connect the test leads to the circuit to be measured and read the stable data.

Warning: Do not input voltage higher than DC 1000V or AC 750Vrms. Higher voltages may be displayed but risk damaging the meter. If input voltage exceeds 30V, the screen will show ⚠ as a safety warning.

DC Millivolt Voltage (DCmV) Measurement

1. Turn the rotary switch to the "TC mV" position.
2. Plug the black test lead into the "COM" plughole and the red test lead into the "VΩ" plughole.
3. Connect the test leads to the circuit to be measured and read the stable data.

Resistance Measurement

Warning: To avoid damage, cut off all power supply to the circuit and discharge all capacitors completely before measuring resistance.

1. Turn the rotary switch to the "Ω" position.
2. Plug the black test lead into the "COM" plughole and the red test lead into the "VΩ" plughole.
3. Connect the test leads to the circuit to be measured and read the stable data.

Notice: If the resistance is an open circuit or beyond the maximum range, the screen will show "OL". The measured resistance may differ from the rated value due to the meter's test current passing through all possible paths.

On-off Test

Warning: To avoid damage, cut off all power supply to the circuit and discharge all capacitors completely before performing an on-off test.

1. Turn the rotary switch to the "Ω" position, then press the blue button to select the on-off test function.
2. Plug the black test lead into the "COM" plughole and the red test lead into the "VΩ" plughole.
3. Connect the test leads to the circuit. If resistance is below approximately 50Ω, the buzzer will beep.

Diode Measurement

Warning: To avoid damage, cut off all power supply to the circuit and discharge all capacitors completely before measuring diodes.

1. Turn the rotary switch to the "Ω" position, then press the blue button to select diode measurement.
2. Plug the black test lead into the "COM" plughole and the red test lead into the "VΩ" plughole.
3. Connect the test leads to the diode and read the stable data.

Forward Test: Connect the red lead to the positive pole and the black lead to the negative pole. The screen will show the approximate forward voltage drop (typically 0.5~0.8V).

Reverse Test: Connect the red lead to the negative pole and the black lead to the positive pole. The screen will typically show "OL".

Capacitance Measurement

Warning: To avoid damage, cut off all power supply to the circuit and discharge all capacitors completely before measuring capacitance.

Capacitance is the ability of an element to store electric charges. Units range from nanofarads (nF) to microfarads (µF).

1. Turn the rotary switch to the "Ω" position, then press the blue button to select capacitance measurement.
2. Plug the black test lead into the "COM" plughole and the red test lead into the "VΩ" plughole.
3. Connect the test leads in parallel with the capacitor and read the stable data.

Notice: If the capacitance is an open circuit or beyond the maximum range, the screen will show "OL". Measuring large capacitance takes longer. For polarized capacitors, connect the red lead to the positive pole and the black lead to the negative pole. Residual voltage, insulation impedance, and dielectric absorption can cause measurement errors.

Thermocouple (TC) Measurement

Warning: To avoid fire hazard or electric shock, do not connect thermocouples to live circuits.

1. Turn the rotary switch to the "TC mV" position, then press the blue button to select thermocouple measurement.
2. Press the START/RANGE button to select the relevant indexing number.
3. Plug the thermocouple into the "COM" and "VΩ" plugholes. Ensure the positive (+) sign of the thermocouple is inserted into the "VΩ" plughole.
4. Read the measurement data on the screen. The main display shows the temperature value, and "RJ-ON" will appear if cold-end compensation is active.

Thermal Resistance (RTD) Measurement

1. Turn the rotary switch to the "RTD Ω" position, then press the blue button to select thermal resistance measurement.
2. Press the START/RANGE button to select the relevant indexing number.
3. Plug the black test lead into the "COM" plughole and the red test lead into the "VΩ" plughole.
4. Connect the test leads to the output end of the thermal resistor to be measured.
5. Read the stable measurement data on the screen.

DC Current Measurement

Warning: Ensure the rotary switch position and input terminals are consistent with the required measurement mode to avoid damage.

1. Turn the rotary switch to the "mA" position.
2. Plug the black test lead into the "COM" plughole and the red test lead into the "mA" plughole.
3. Connect the test leads to the circuit to be measured and read the stable data.

AC Current Measurement

Warning: Ensure the rotary switch position and input terminals are consistent with the required measurement mode to avoid damage.

1. Turn the rotary switch to the "mA" position, then press the blue button to select AC current measurement.
2. Plug the black test lead into the "COM" plughole and the red test lead into the "mA" plughole.
3. Connect the test leads to the circuit to be measured and read the stable data.

Loop Current Measurement

This function measures current under a constant 24VDC voltage and can be used for measuring the transmitter loop. The meter can be connected to the transmitter instead of a signal regulator.

Warning: The typical loop power supply is 24VDC. Voltage between terminals may exceed 24V depending on conditions like loop current and internal series resistance.

1. Turn the rotary switch to the "LOOP POWER mA HART" position. The screen will show "LOOP POWER".
2. Plug the black test lead into the "mA" plughole and the red test lead into the "LOOP" plughole.
3. Connect the test leads to the circuit to be measured and read the stable data.

Loop Current Measurement with 250Ω HART Resistance

1. Turn the rotary switch to the "LOOP POWER mA HART" position, then press the blue button to select this function. The screen will show "LOOP POWER" and "250Ω HART".
2. Plug the black test lead into the "mA" plughole and the red test lead into the "LOOP" plughole.
3. Connect the test leads to the circuit to be measured and read the stable data.

Output Functions

The meter can output simulated resistance, thermal resistance, DC voltage, thermocouple, frequency, and current values set by the user.

Warning: Do not apply voltage at the output end, as improper voltage can damage internal circuits.

Current Output (SOURCE mode)

This mode outputs a specified current continuously or in manual steps (25% or 100%). It is used for current supply to passive circuits (loops without power supply). The SOURCE mode consumes more battery energy than SIMULATE mode.

Warning: Do not apply voltage of 30V or above on output terminals. Keep voltage between the circuit and earth below 30V. Use original probes and leads.

1. Turn the rotary switch to the "mA SOURCE" position. The screen will show "SOURCE" and "LOOP POWER". Output is set to 0mA.
2. Plug the black test lead into the "COM" plughole and the red test lead into the "LOOP" plughole.
3. Connect the test leads to the circuit to be measured.
4. Press the REL ▲ button to select the indicative value for non-automatic output of current waveforms. Units 'mA' and '25%' (or '100%') will be shown. 0% corresponds to 4mA, and 100% to 20mA.
5. For digit-setting output, use the arrow buttons to select and adjust the digit. Hold an arrow button for 1 second to change values continuously.
6. Press the ON/OFF/HOLD button to connect/disconnect output. "ON" will be shown before output value.

Current Output (SIMULATE mode)

In SIMULATE mode, the meter draws current from an external voltage source via the SIMULATE(+) terminal. It can simulate a two-wire transmitter in loop tests.

Warning: Before connecting test leads, turn the rotary switch to any milliampere output position. Otherwise, low impedance may cause current up to 35mA in the circuit. Apply voltage as per Figure 4.3; do not connect inversely.

Notice: The meter can be connected to test a transmitter or signal regulator. When external power supply current is 20mA, keep voltage within 15-48V.

1. Turn the rotary switch to the "mA SIMULATE" position. The screen will show "SOURCE" and "SIMULATE". Output is set to 0mA.
2. Plug the black test lead into the "COM" plughole and the red test lead into the "mA" plughole.
3. Connect the test leads to the circuit to be measured.
4. Other button operations are the same as in SOURCE mode.

Voltage Output

1. Turn the rotary switch to the "VTC" position. The screen will show "SOURCE".
2. Plug the black test lead into the "COM" plughole and the red test lead into the "mA" plughole.
3. Connect the test leads to the input end of the user meter.
4. Press the START/RANGE button to select a range (100mV, 1V, or 10V).
5. Use the arrow buttons to select and adjust the setting digit. Hold an arrow button for 1 second to change values continuously.
6. Press the ON/OFF/HOLD button to connect/disconnect output. "ON" will be shown.

Frequency Output

1. Turn the rotary switch to the "VTC" position, then press the blue button to select frequency output. The screen will show "SOURCE" and "Hz".
2. Plug the black test lead into the "COM" plughole and the red test lead into the "mA" plughole.
3. Connect the test leads to the input end of the user meter.
4. Press the START/RANGE button to select the output range (1~100 Hz, 0.1~1.1KHz, 1.0~11.0 KHz).
5. Use the arrow buttons to select and adjust the setting digit. Hold an arrow button for 1 second to change values continuously.
6. Press the ON/OFF/HOLD button to connect/disconnect output. "ON" will be shown.

Simulated Output of Resistance and Thermal Resistance (RTD)

Notice: Resistance simulation uses a four-wire system for calibration. If using two-wire, consider errors from lead resistance (approx. 0.1Ω). Capacitance between the meter's output terminal and the meter under test greater than 0.1µF may cause incorrect resistance. For correct output simulation, the excitation current should be within 0.5mA~2mA. An excitation current of +1mA is recommended for precision.

1. Turn the rotary switch to the "RTD Ω" position. The screen will show "SOURCE". Press the blue button to select resistance or thermal resistance (RTD) output. The screen will show the unit 'Ω' or '°C', and the thermal resistance indexing number 'Pt100'.
2. Plug the black test lead into the "LOOP" plughole and the red test lead into the "mA" plughole.
3. Connect the test leads to the input end of the user meter.
4. For thermal resistance (RTD) function, press the START/RANGE button to select the relevant indexing number.
5. Use the arrow buttons to select and adjust the setting digit. Hold an arrow button for 1 second to change values continuously.
6. Press the ON/OFF/HOLD button to connect/disconnect output. "ON" will be shown.

5. Maintenance

This chapter covers basic maintenance steps. Any repair, calibration, or maintenance not covered here should be performed by experienced personnel or by contacting authorized service centers.

General Maintenance

• Clean the meter enclosure regularly with a wet cloth and mild detergent. Do not use abrasive agents or solvents.
• If the meter is not used for a long time, remove the batteries.
• Impurities or moisture in plugholes can affect readings. To clean connection ports:
  1. Switch off the meter and remove all test leads.
  2. Clean impurities from the connection ports.
  3. Clean each connection port with a new swab dipped in alcohol.

Battery Replacement

This meter uses four 1.5V (LR6) alkaline batteries.

Warning: To avoid electric shock or personal injury, remove test leads from the meter before opening the battery cover. Tighten screws on the battery cover before using the meter.

Notice: Do not mix old and new batteries. Pay attention to battery polarity markings inside the battery box. Remove batteries if the meter is not used for a long time. Dispose of used batteries according to local regulations.

1. Shut down the meter and disconnect all test leads.
2. Lift the holder, remove the four screws on the battery box with a cross screwdriver, and then remove the battery door.
3. Install four new 1.5V (LR6) alkaline batteries into the box, observing polarity.
4. Assemble the battery door and tighten the screws.

Fuse Replacement

The mA input plughole is protected by a 500mA/250V quick-acting fuse. Use only defined fuses to avoid personal injury and meter damage.

Warning: Use only specified 500mA/250V quick-acting fuses.

To check if the fuse is blown:

1. Turn the rotary switch to the "mA" position.
2. Plug the black test lead into "COM" and the red test lead into "mA".
3. Measure resistance between the test leads with an ohmmeter. If resistance is about 20Ω, the fuse is OK. If the meter indicates an open circuit, the fuse is blown.

To replace a fuse (refer to Figure 5.2):

1. Remove test leads and switch off the meter.
2. Remove the protective cover and the four screws on the lower enclosure with a cross screwdriver, then remove the lower enclosure.
3. Replace the quick-acting fuse on the main board.
4. Assemble the lower enclosure.
5. Fit on the protective cover.

6. Meter Settings

Default factory settings can be modified. Some settings are general, applicable to all functions, while others are specific to certain functions.

Selection of Setting Items

To enter setting mode, ensure the meter is shut down. Press the START/RANGE button, then turn the rotary switch to any position other than OFF. The auxiliary display will show setting items, and the main display will show factory defaults. Press the RATE button to cycle through setting items. Press the Hz % button to save settings (the main display will show "SAVE"). Shut down the meter after setting is completed.

7. Technical Specifications

Safety and Conformity

• Overload protection: V~COM terminal: AC1000V/10 seconds; mAV terminal: 500mA/250V quick-acting fuse.
• Regulatory compliance: IEC61010-1 (CAT IV 600V, CATIII1000V, pollution level II).
• Electromagnetic compatibility: Consistent with Group 1 and Class B of IEC61326-1.
• Surge protection: 8kV (As per IEC61010.1-2001).
• Authentication mark: CE.
• Quality standard: Developed, designed, and produced according to ISO 9001.

General Characteristics

Detailed Precision Indexes for Measurement

Precision is affirmed within one year after calibration, with a work temperature of 23±5°C and relative humidity of 75%. Precision is marked as: ± ([reading%] + count), where "count" is the increased or decreased number at the lowest significance digit.

Notes on Measurement Precision:

• AC measurement: True RMS, 20Hz~1kHz, range of 10%~110%.
• Thermocouple measurement adopts the ITS-90 temperature scale. Precision does not include errors in cold-end compensation or influences of thermo-electrical potential.
• Thermal resistance measurement adopts the Pt100-385 temperature scale. Precision does not include errors due to lead resistance.
• For frequency measurement, readings for signals below 3Hz will be zero.

Detailed Precision Indexes for Output

Input Characteristics

8. User Tips

Based on common user experiences and questions, here are some tips for using your Victor 79A+ Digital Process Multimeter:

• Battery Life: To maximize battery life, always turn the rotary switch to the OFF position when the meter is not in use, even with automatic shutdown enabled.
• Probe Connection: Ensure test leads are securely connected to the correct plugholes for the desired measurement to prevent inaccurate readings or damage.
• Capacitor Discharge: Always discharge capacitors before testing them to avoid damage to the meter and ensure accurate readings.
• Fuse Check: If current measurements are inconsistent or the meter doesn't function as expected in current modes, check the fuse as described in the Maintenance section.
• Environmental Conditions: While the meter is robust (IP65), avoid prolonged exposure to extreme temperatures or high humidity, especially without moisture condensation, to maintain precision.

9. Warranty and Support

The present operation instruction is subject to change without notice. The content of this instruction manual is regarded as correct at the time of publication. If any user finds mistakes, omissions, or other issues, they are requested to contact the manufacturer.

The manufacturer is not liable for any accident or hazard arising from customer misuse or inadvertent operation of the device.

The functions described in this operation instruction should not be used as grounds to apply this product to a particular purpose not explicitly stated or intended.

A comprehensive user manual is also available in PDF format from the manufacturer.

For technical support or service inquiries, please refer to the contact information provided by your retailer or the manufacturer's official website.

10. Product Video

Watch this video to see the manufacturing process of Victor/RuoShui multimeters, showcasing the quality control and assembly procedures.