Mastech MS8235 Digital Multimeter with LAN Tester User Manual

Introduction

The Mastech MS8235 is a versatile 2-in-1 instrument combining a full-featured auto-ranging digital multimeter with a comprehensive LAN cable tester. This device is engineered for precision and safety, making it an essential tool for electricians, network technicians, and DIY enthusiasts. It provides accurate measurements for various electrical parameters and efficiently diagnoses common network cable issues.

Safety Information

Always adhere to safety precautions when operating the Mastech MS8235. Failure to do so may result in electric shock, injury, or damage to the meter or equipment under test.

• CAT III 600V Rating: This meter is designed for measurements in distribution boards, circuit breakers, wiring, including cables, bus-bars, junction boxes, switches, socket outlets in the fixed installation, and industrial use with permanent connection to the fixed installation. Do not exceed the specified voltage and current limits.
• Before each use, inspect the test leads for any damage. Do not use if insulation is cracked or if the leads are exposed.
• Ensure the rotary switch is in the correct position for the desired measurement before connecting the test leads to the circuit.
• Do not attempt to measure voltage or current on circuits exceeding the meter's maximum input ratings.
• Exercise extreme caution when working with live circuits. Always use appropriate personal protective equipment (PPE).
• Never operate the meter with the battery cover removed.
• If the 'Low Battery' indicator appears, replace the batteries immediately to ensure accurate readings.

Product Overview

Front view of the Mastech MS8235 Digital Multimeter with LAN Tester, showing the LCD display, function buttons, rotary switch, and input jacks.

Components and Controls:

• LCD Display: Large digital display (2000 counts) showing measurement values, units (kΩ, kHz, mµVA), function indicators (LANPHONE, AUTO, MAX, battery), and LAN test results (OPEN, SHORT, REVERSED, MISWIRE, SPLIT PAIRS, SHIELD).
• FUNC Button: Selects different functions within a single rotary switch position (e.g., AC/DC, Diode/Continuity).
• RANGE Button: Toggles between auto-ranging and manual ranging modes.
• MAX Button: Displays the maximum measured value.
• HOLD Button: Freezes the current display reading.
• TEST Button (Blue): Initiates the LAN cable test.
• Backlight Button (Yellow): Activates or deactivates the display backlight.
• Rotary Switch: Used to select the desired measurement function (OFF, ~V, =V, Ω, Diode/Continuity, Hz, µA~, mA~, A~, Net Cable, NCV).
• Input Jacks:
  • 10A Jack: For current measurements up to 10A.
  • COM Jack: Common (negative) input for all measurements.
  • VΩHzµAmA Jack: Positive input for voltage, resistance, frequency, diode, continuity, and current measurements up to 200mA.

Setup

Battery Installation:

1. Ensure the meter is turned OFF.
2. Locate the battery compartment on the rear of the meter.
3. Unscrew the retaining screw(s) and remove the battery cover.
4. Insert two (2) AA batteries, observing the correct polarity (+/-) as indicated inside the compartment.
5. Replace the battery cover and secure it with the screw(s).

Connecting Test Leads:

• For most measurements (voltage, resistance, frequency, diode, continuity, and current up to 200mA), insert the black test lead into the COM jack and the red test lead into the VΩHzµAmA jack.
• For high current measurements (up to 10A), insert the black test lead into the COM jack and the red test lead into the 10A jack.

Operating Instructions

General Operation:

• Auto-Ranging: The meter automatically selects the appropriate measurement range. Press the RANGE button to switch to manual ranging if desired.
• Data Hold: Press the HOLD button to freeze the current reading on the display. Press again to release.
• Backlight: Press the yellow backlight button to illuminate the display for better visibility in low-light conditions. Press again to turn off.
• Auto Power Off: The meter will automatically power off after a period of inactivity to conserve battery life.

Multimeter Functions:

1. DC Voltage Measurement (=V):
   • Set the rotary switch to the =V position.
   • Connect the red test lead to the positive side of the circuit and the black test lead to the negative side.
   • Read the DC voltage value on the display.
2. AC Voltage Measurement (~V):
   • Set the rotary switch to the ~V position.
   • Connect the test leads across the AC voltage source.
   • Read the AC voltage value on the display.
3. DC/AC Current Measurement (µA=~, mA=~, A=~):
   • Set the rotary switch to the appropriate current range (µA, mA, or A).
   • Press the FUNC button to select DC or AC current.
   • Connect the meter in series with the circuit. Ensure correct jack usage (VΩHzµAmA for µA/mA, 10A for A).
   • Read the current value on the display.
4. Resistance Measurement (Ω):
   • Set the rotary switch to the Ω position.
   • Ensure the circuit is de-energized before measuring resistance.
   • Connect the test leads across the component to be measured.
   • Read the resistance value on the display.
5. Frequency Measurement (Hz):
   • Set the rotary switch to the Hz position.
   • Connect the test leads across the signal source.
   • Read the frequency value on the display.
6. Diode Test and Audible Continuity:
   • Set the rotary switch to the Diode/Continuity position.
   • Press the FUNC button to toggle between Diode Test and Continuity Test.
   • For Diode Test: Connect the red lead to the anode and black lead to the cathode. Read the forward voltage drop. Reverse leads for reverse bias.
   • For Continuity Test: Connect leads across the circuit. An audible beep indicates continuity (low resistance).
7. Non-Contact Voltage (NCV) Detection:
   • Set the rotary switch to the NCV position.
   • Move the top part of the meter near a live AC voltage source.
   • The meter will beep and the NCV indicator will light up when AC voltage is detected.

LAN Tester Function:

The MS8235 can test RJ45 (Ethernet) and RJ11/RJ12 (Phone) cables for common wiring faults.

1. Set the rotary switch to the Net Cable position.
2. Connect one end of the network cable to the RJ45 port on the top of the meter.
3. Connect the other end of the network cable to the remote unit (if applicable, not explicitly mentioned but implied for full testing).
4. Press the blue TEST button to initiate the cable test.
5. The display will show the status of each wire pair (1-8 and Shield) indicating: OPEN (broken wire), SHORT (short circuit), REVERSED (reversed pair), MISWIRE (incorrect wiring), or SPLIT PAIRS (pairs split between different connectors).
6. For phone cables, the display will indicate RED-TIP and RED-RING status.

Maintenance

Battery Replacement:

When the 'Low Battery' indicator appears on the display, replace the batteries as described in the 'Setup' section to ensure accurate measurements and proper operation.

Cleaning:

Wipe the meter's casing with a damp cloth and mild detergent. Do not use abrasives or solvents. Ensure the meter is completely dry before use.

Troubleshooting

• No Display/Meter Not Turning On: Check battery installation and ensure batteries are fresh.
• Inaccurate Readings: Ensure the correct function is selected on the rotary switch. Check test lead connections. Replace batteries if the 'Low Battery' indicator is on.
• LAN Test Errors: Ensure both ends of the cable are properly connected. Verify the cable type (RJ45/RJ11) matches the test.
• No NCV Detection: Ensure the rotary switch is set to NCV. The NCV function detects AC voltage; it will not respond to DC voltage.

Specifications

Warranty and Support

Mastech products are manufactured to high quality standards. For warranty information, technical support, or service inquiries, please refer to the contact information provided with your purchase or visit the official Mastech website. Keep your purchase receipt as proof of purchase for warranty claims.